Flow control system for aircraft maneuvering and related methods

Abstract

A system is designed to control leading-edge vortex flow and liftoff on aircraft using supersonic jet (SSJs) positioned on the wing surface. Flight control inputs for flight attitude and status inputs from aircraft systems are processed to determine the necessary SSJ activation to influence the leading-edge vortex flow over the wing, achieving the desired flight attitude. The system can activate SSJs for specific durations, directions, and amount of activation levels. Additionally, the system can manage multiple SSJs to expel air in various directions, influencing the aircraft's roll, yaw, and pitch moments and change lift at trimmed pitch.

Description

FLOW CONTROL SYSTEM FOR AIRCRAFT MANEUVERINGAND RELATED METHODSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to co-pending U.S. Provisional Patent Application No. 63 / 645,264, filed May 10, 2024 and titled “Time-Dependent Leading-Edge Vortex Control.” The entire contents of the above-identified priority application are hereby incorporated by reference herein.TECHNICAL FIELD

[0002] The subject matter disclosed herein relates to flow control systems and methods for aircraft maneuvering, and, more particularly, to wing leading-edge vortex control to affect the forces and moments acting on an aircraft, thus producing stability and maneuverability.BACKGROUND

[0003] The field of aerodynamics has long been focused on improving the efficiency and control of aircraft, particularly in the context of tailless designs and advanced wing configurations. Traditional aircraft control methods, such as wing warping and surface deflection, have been the cornerstone of flight control since the early 20th century. However, as aircraft designs have evolved, particularly with the advent of stealth and unmanned aerial vehicles, the limitations of these conventional control mechanisms have become more apparent. Tailless aircraft, such as those with delta wings or blended wing body designs, present unique challenges in maintaining stability and control due to their inherent aerodynamic characteristics.

[0004] The need for innovative control solutions is further driven by the desire to enhance the performance and maneuverability of these advanced aircraft configurations. The leading-edge vortex (LEV) is an aerodynamic feature that can significantly influence the lift and stability of an aircraft. In tailless designs, the ability to control the LEV can provide substantial benefits in terms of pitch control and overall aerodynamic efficiency. However, traditional control surfaces are often inadequate for managing the complex flow dynamics associated with LEVs, especially in configurations with sharp leading edges and high sweep angles. This issue has led to a growing interest in active flow control techniques that can dynamically influence theaerodynamic forces acting on an aircraft, offering the potential for improved performance and control in challenging flight conditions.Tests on swept back wings of airplane models suggest that an LEV created on such wings affects the pressure distribution on the wings and hence the forces and moments acting on a wing (for example, lift, drag, pitch, roll, and yaw). On thin wings and low incidence angles , the LEV is confined to the leading-edge (LE) region of the wing, resulting in its name LEV.. However, as the incidence angle increases the LEV might separate from the surface and move away from the LE. A discontinuity in the surface of the wing, such as a crank, a snag, a fence, or a vortilon, may hasten the separation process of the LEV (referenced as LEV liftoff), which may be unsteady and result in large periodic oscillations in the flow that may cause buffet and wing-drop. This LEV liftoff thus restricts the usage of the wing to low lift coefficients that are far below the stalling angle of the wing. .SUMMARY

[0005] In some aspects, the techniques described herein relate to a system to control leadingedge vortex flow and liftoff on aircraft, including: at least one supersonic jet (SSJ) disposed on a surface of a wing; a storage device; and a processor communicatively coupled to the storage device, wherein the processor executes application code instructions that are stored in the storage device to cause the system to: receive control inputs for a flight attitude from a peripheral device, the control inputs indicating a desired force in pitch, roll, and / or yaw, lift at trimmed pitch, or change therein, for the aircraft; receive status inputs from aircraft systems, sensors, or components indicating airspeed, angle of incidence, altitude, bank angle, local airflow over the wing, or other suitable inputs; determine, based on the control inputs and the status inputs, an amount of SSJ activation to influence flow of a leading-edge vortex (LEV) over the wing to execute the desired flight attitude; and communicate instructions to one more SSJs to activate for a specified time, in a specified direction, and with a specified amount of activation to achieve the desired flight attitude.

[0006] In some aspects, the techniques described herein relate to a system, wherein the peripheral device is a flight controller.

[0007] In some aspects, the techniques described herein relate to a system, wherein for each instructed SSJ, an SSJ controller receives the instructions and activates the SSJ for the specified time and with the specified amount of activation.

[0008] In some aspects, the techniques described herein relate to a system, wherein for each instructed SSJ, an SSJ controller receives the instructions, controls the SSJ to turn its amount of activation in the specified direction, and activates the SSJ for the specified time and with the specified amount of activation.

[0009] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs, each of the SSJs configured to expel a jet of air in a different direction with respect to the other SSJs, and wherein determining an amount of SSJ activation includes determining at least one of the SSJs to activate based on the desired direction of expelled air.

[0010] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs disposed on a left side of the wing and a plurality of SSJs disposed on a right side of the wing, and wherein determining an amount of SSJ activation includes determining at least one of the SSJs to activate on the left side of the wing and at least one of the SSJs to activate on the right side of the wing.

[0011] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ activated on the left side of the wing expels air with a vector component in a direction of air flowing over the wing, and the at least one SSJ activated on the right side of the wing expels air with a vector component in a direction opposite to air flowing over the wing

[0012] In some aspects, the techniques described herein relate to a system, wherein the specified direction is angled with respect to a direction of travel of the wing through air.

[0013] In some aspects, the techniques described herein relate to a system, wherein the specified direction includes at least a vector component that is in the direction of travel of the wing through air.

[0014] In some aspects, the techniques described herein relate to a system, further including an air source that provides compressed air to the at least one SSJ.

[0015] In some aspects, the techniques described herein relate to a system, wherein the air source includes a compressor.

[0016] In some aspects, the techniques described herein relate to a system to control leadingedge vortex flow and liftoff on aircraft, including: a wing; and at least one supersonic jet (SSJ) disposed on a surface of the wing relative to a location of liftoff of a leading-edge vortex (LEV) generated over the wing, the at least one SSJ being oriented such that a jet output from the at least one SSJ influences flow of the LEV over the wing.

[0017] In some aspects, the techniques described herein relate to a system, wherein the jet output from the at least one SSJ influences the flow of the LEV by promoting or delaying liftoff of the LEV from the wing.

[0018] In some aspects, the techniques described herein relate to a system, wherein the jet output from the at least one SSJ influences the flow of the LEV by changing a location on the wing where liftoff of the LEV occurs.

[0019] In some aspects, the techniques described herein relate to a system, wherein the jet output from the at least one SSJ influences the flow of the LEV by controlling the interaction of multiple LEVs generated over the wing.

[0020] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ outputs the jet at an angle with respect to a direction of travel of the wing through air.

[0021] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ outputs the jet with at least a vector component that is in the direction of travel of the wing through air.

[0022] In some aspects, the techniques described herein relate to a system, wherein the jet output from the at least one SSJ is pulsed in relation to a periodicity of liftoff of the LEV from the wing to influence flow of the LEV over the wing.

[0023] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a single SSJ.

[0024] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs.

[0025] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs that are activatable individually or in groups of two or more.

[0026] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs, and wherein less than all of the SSJs are activated at the same time.

[0027] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs, and only one of the SSJs is activated at a time.

[0028] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs, and a different one or more of the SSJs is activated to provide a desired control depending on an attitude of the aircraft to which the wing is attached.

[0029] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a plurality of SSJs on a left side of the wing and a plurality of SSJs on a right side of the wing, and wherein at least one SSJ on the left side of the wing and at least one SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0030] In some aspects, the techniques described herein relate to a system, wherein the at least one SSJ includes a single SSJ on a left side of the wing and a single SSJ on a right side of the wing, and wherein the SSJ on the left side of the wing and the SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0031] In some aspects, the techniques described herein relate to a system, further including an aircraft to which the wing is attached.

[0032] In some aspects, the techniques described herein relate to a system, wherein the aircraft is a tailless aircraft.

[0033] In some aspects, the techniques described herein relate to a system, wherein the wing includes a swept back wing.

[0034] In some aspects, the techniques described herein relate to a system, wherein the wing includes a crank, and wherein the at least one SSJ is positioned relative to the crank where liftoff of the LEV occurs.

[0035] In some aspects, the techniques described herein relate to a system, wherein the jet output from the SSJ is angled within a range of about 0° to about 360° with respect a direction of flight of the wing.

[0036] In some aspects, the techniques described herein relate to a system, wherein the jet output from the SSJ is angled within a range of about 15° to about 195° degrees with respect to a direction of flight of the wing.

[0037] In some aspects, the techniques described herein relate to a system, wherein the jet output from the SSJ is angled about 15°, about 60°, about 105°, about 150°, or about 195° with respect to a direction of flight of the wing.

[0038] In some aspects, the techniques described herein relate to a method to control leadingedge vortex flow and liftoff on aircraft, including: providing a wing; providing at least one air jet disposed on an upper surface of the wing relative to a location of liftoff of a leading-edge vortex (LEV) generated over the wing, the at least one air jet being oriented such that a jet ofair output from the at least one air jet influences flow of the LEV over the wing; and expelling a jet of air from the at least one air jet.

[0039] In some aspects, the techniques described herein relate to a method, wherein the at least one air jet includes a pneumatic jet actuator.

[0040] In some aspects, the techniques described herein relate to a method, wherein the pneumatic jet actuator includes one of a supersonic jet or a sweeping jet actuator.

[0041] In some aspects, the techniques described herein relate to a method, wherein the jet of air output from the at least one air jet influences the flow of the LEV by promoting or delaying liftoff of the LEV from the wing.

[0042] In some aspects, the techniques described herein relate to a method, wherein the jet of air output from the at least one air jet influences the flow of the LEV by changing a location on the wing where liftoff of the LEV occurs.

[0043] In some aspects, the techniques described herein relate to a method, wherein the jet of air output from the at least one air jet influences the flow of the LEV by controlling the interaction of multiple LEVs generated over the wing.

[0044] In some aspects, the techniques described herein relate to a method, wherein the at least one SSJ outputs the jet at an angle with respect to a direction of travel of the wing through air.

[0045] In some aspects, the techniques described herein relate to a method, wherein the at least one SSJ outputs the jet with a vector component that is in the direction of travel of the wing through air.

[0046] In some aspects, the techniques described herein relate to a method, wherein the jet of air output from the at least one air jet is pulsed in relation to a periodicity of liftoff of the LEV from the wing to influence flow of the LEV over the wing.

[0047] In some aspects, the techniques described herein relate to a method, wherein the at least one air jet includes a single air jet.

[0048] In some aspects, the techniques described herein relate to a method, wherein the at least one air jet includes a plurality of air jets.

[0049] In some aspects, the techniques described herein relate to a method, wherein the at least one air jet includes a plurality of supersonic jets (SSJs) on a left side of the wing and a plurality of SSJs on a right side of the wing, and wherein an air jet is expelled from at least one SSJ on the left side of the wing and at least one SSJ on the right side of the wing to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0050] In some aspects, the techniques described herein relate to a method, wherein the air jet expelled from the at least one SSJ on the left side of the wing includes a vector component in a direction of travel of the wing through the air and the air jet expelled from the at least one SSJ on the right side of the wing includes a vector component that is opposite to the direction of travel of the wing through the air.

[0051] In some aspects, the techniques described herein relate to a method, wherein the provided at least one air jet includes a supersonic jet (SSJ) on a left side of the wing and an SSJ on a right side of the wing, and wherein the SSJ on the left side of the wing and the SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0052] In some aspects, the techniques described herein relate to a method, wherein the SSJ on the left side of the wing and the SSJ on a right side of the wing expel air in different directions relative to a flow of air over the wing.

[0053] In some aspects, the techniques described herein relate to a method, further including providing an aircraft to which the wing is attached.

[0054] In some aspects, the techniques described herein relate to a method, wherein the provided wing includes a swept back wing including a crank, and wherein the at least one air jet is positioned relative to the crank where liftoff of the LEV occurs.

[0055] In some aspects, the techniques described herein relate to a method, wherein the provided wing includes a swept back wing, and wherein the at least one pulsating air jet is positioned close to the apex of the wing.

[0056] In some aspects, the techniques described herein relate to a system to control leadingedge vortex flow and liftoff on aircraft as shown and described.

[0057] In some aspects, the techniques described herein relate to a method to control leadingedge vortex flow and liftoff on aircraft as shown and described.

[0058] In some aspects, the techniques described herein relate to a flight control system to control leading-edge vortex flow and liftoff on aircraft as shown and described.BRIEF DESCRIPTION OF THE DRAWINGS

[0059] An understanding of the features and advantages of the invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention may be utilized, and the accompanying drawings of which:

[0060] Figure 1 is a plan view of a tailless aircraft having a blended-body lambda wing incorporating a flow control system for flight control and maneuvering.

[0061] Figure 2 is a block diagram depicting an aircraft flight control system 200 to control forces and moments on aircraft.

[0062] Figure 3 as a block flow diagram depicting an aircraft flight control method 300 to control forces and moments on aircraft.

[0063] Figure 4 depicts a computing machine and a module.

[0064] Figures 5a-5c are plots of streamlines showing the effect of jet orientation on the LEV structure.

[0065] Figures 6a-6b show the effect of Aspect Ratio (AR) on the LEV structure and pitch moment due to actuation (ACLM) dependence on the jet orientation (P) for (a) a short outer wing with an AR=2.34 and (b) a longer outer wing with an AR=3.9, at a crank angle of 0°.

[0066] Figure 7 shows the pitch moment due to actuation (ACLM) dependence on the jet orientation (P) for a long outer wing with an AR=3.9 at a crank angle of 30°.

[0067] Figure 8 depicts cross-sectional and plan views of the SWIFT model design of the wing depicting various design parameters and features.

[0068] Figure 9 depicts graphs showing the effect of location of a pair of sweeping jet actuators (SJAs), disposed normal to the LE, on pitch (CLM), yaw (CLN), and roll (CLL) moments using nij =3.5 g / s.

[0069] Figure 10 depicts graphs showing the effect of location of a pair of supersonic jets (SSJs), disposed normal to the LE, on CL , CLN, and CLL using approximately the same power that was used in conjunction with the SJA results shown in Figure 9.

[0070] Figure 11 depicts graphs showing the effect of changing the jet orientation of a single SSJ located approximately at location S9 of Figure 1 (location L9 of Figure 8) on CLM, CLN, and CLL using mj=2 g / s.

[0071] The figures herein are for illustrative purposes only and are not necessarily drawn to scale.DETAILED DESCRIPTION

[0072] This disclosure provides systems and methods to control a leading-edge (LE) vortex(LEV) and its liftoff on aircraft, by small pneumatic jet actuators, such as supersonic jets steady (SSJs), positioned on a wing surface. By preventing LEV liftoff from the surface or controlling its path after separation, more pitch-trimmed lift may be extracted from the wing,thus gaining stability and reducing flutter. Changing the jet orientation with respect to freestream can assist with preventing liftoff and / or controlling the path of the LEV after separation for varying conditions. The SSJs can be used to actively manipulate the formation, structure, and trajectory of the LEV, thereby influencing the aerodynamic stability and control of the aircraft. The system may include a processor that determines the amount of SSJ activation needed to influence the LEV flow based on control and status inputs. Instructions can be communicated to selected SSJs to activate them for a specified time, direction, and amount of activation to achieve the desired flight attitude or other desired characteristics. The SSJs expel a jet of air to modify the LEV structure, delay its liftoff, or change the location of its liftoff on the wing. If the aircraft design generates two or more LEVs, the SSJs actuation may affect one or more LEV structures, and their interaction. This approach may enable an on- demand modulation of aerodynamic forces and moments for aircraft maneuvering, particularly in tailless aircraft with swept wings or the family of delta wing configurations.

[0073] An LEV on an airplane model is found to lift-off, change its orientation, and proceed periodically outboard, causing large pressure oscillations. The result of liftoff of the LEV is known as flutter or buffet, but the flow mechanism leading to the liftoff and flutter was not understood previously and neither was it predicted by computational fluid dynamics (CFD). CFD considers liftoff of the LEV to be continuous or quasi-continuous and is therefore based on time-averaged flow data. The technology described herein has identified a periodic relationship of the LEV’S liftoff. A crank or a protuberance in the LE may initiate and promote the process of the LEV’s liftoff that may start at low incidence and continue over a wide range of incidence angles prior to stall. A high-speed, small jet may delay the vortex liftoff and change its path, thus alleviating the buffet while also providing pitch control and increased lift at trimmed pitch. Detailed, time resolved mapping of the flow, and its surface pressure provides a design tool that avoids flutter by using active flow control (AFC). Flutter on swept back wings (such as a swept, delta, diamond, X, or similar wings, which may be referred to herein collectively as “swept wings”) may be controlled through the manipulation of the LEV over the wing, including control of an LEV that is periodically being shed over the wing. The LEV structure, path, and interaction of multiple LEVs are controlled based on conventional LEV analysis and / or based on time-dependent data that assesses the periodic flow of the LEV over the wing over time.

[0074] Identification of this periodic vortex shedding allows control of the LEV via active flow control (AFC). One or more high-speed jets positioned relative to the LEV and liftoff locations,can delay the vortex liftoff and change its path, thus alleviating the buffet while also providing pitch, roll, and / or yaw control. In certain instances, a single jet is sufficient.

[0075] Conventional wing and aircraft design analyzes LEV liftoff and flow. At liftoff, the LEV flows downstream and outboard and affects airflow over the outer portion of the wing, and corresponding control surfaces. Combat aircraft with swept wings utilize a separated LEV to enhance the effectiveness of control surfaces, thus improving maneuverability. As angle of incidence increases, the wing will lose lift due to separation induced by LEV liftoff. The flow separation and the associated flutter reduce the wing and aircraft performance and limit the flight envelope. It thus restricts the usage of the aircraft to low lift coefficients that are far below the stalling angle of the wing. To compensate for the flutter effect, designers increase wing size or change shape to provide additional lift at various angles of incidence, and / or stiffen the wings to provide better structural integrity, thus increasing weight. Thus, conventional aircraft design based on assumed steady or quasi-steady flow of the LEV requires a relatively larger wing to provide sufficient lift at various angles of incidence within the flight envelope to accommodate for the loss of lift caused by the flutter associated with LEVs.

[0076] Identification of the periodic (time-dependent) nature of LEVs allows increased control of LEVs for flight. For example, the location of unsteadiness associated with LEVs can be changed relative to the wing or aircraft control surfaces to increase lift at the same angles of incidence and to change aircraft pitching or other moments for maneuverability. Providing increased lift can allow utilization of a smaller aircraft wing to provide the same performance characteristics of previous larger wings; however, the smaller wings have reduced weight and drag characteristics leading to overall increased aircraft performance.

[0077] Active flow control (AFC) can be utilized to control LEV liftoff and flow. One or multiple sweeping jet actuators (SJAs) and / or supersonic jets (SSJs) (or other suitable air jet) can be utilized in AFC to control LEV liftoff and flow. A high speed, small jet disposed relative to the location of LEV liftoff may delay the vortex liftoff and change its path, thus alleviating the buffet while also providing pitch and yaw control.

[0078] In one example of the technology described herein, a small jet positioned relative to the LE changes the location of liftoff of the LEV, which changes the characteristics of the flow over the wing. The wing provides slightly higher lift under controlled conditions, and the buffet associated with the oscillatory aspect of the LEV can be reduced or eliminated over a larger range of angles of incidence. This design also mostly affects pitching moment when controlled over both wings; however, asymmetric application of the LEV control on the left and rightwings can be used to control yaw and roll moments, thus changing its course or responding to gusts.

[0079] In wing design, increasing the angle of incidence at a given speed commonly increases lift. At a certain point, the angle of incidence cannot be further increased because of flutter induced by liftoff of the LEV. Various factors affect the location of LEV liftoff, such as wing design, speed, angle of attack, current maneuver, and current pitch, roll, and yaw moments. Wing size, shape, or other wing characteristics are increased to increase lift at lower angles of incidence.

[0080] The technology described herein delays the liftoff of the LEV as angle of incidence is increased, which results in reduced flutter for the same angle of incidence compared toa configuration without the technology. Accordingly, the technology described herein allows a wing to produce increased lift at higher angles of incidence. The design improvements also result in reducing the size, weight, drag, and other characteristics associated with the wing, which increase the flight characteristics of corresponding aircraft. For example, a smaller wing can be provided to obtain the same lift as a previous conventional wing. Or, a conventional wing will provide more lift with the technology described herein at a given airspeed, angle of incidence, etc., resulting in increased maneuverability for the corresponding aircraft.

[0081] As described herein, the unsteady liftoff of the LEV produces flutter of the wing.. Second or multiple LEVs may form and develop along the span of the wing. The technology described herein has identified the time-dependent (periodic) nature of the LEV liftoff and travel. This process repeats multiple times per second causing pressure oscillations at the wing tips, which results in the flutter experienced by the wing / aircraft. Delaying or otherwise controlling the LEV liftoff reduces the experienced flutter for a given angle of incidence / airspeed, thereby increasing the performance of the wing. Additionally, controlling the LEV structure and trajectory affects pitch, roll, and yaw moments on the aircraft and can be controlled to provide desired flight characteristics and / or to improve wing performance and design.Examples

[0082] Now having described the embodiments of this disclosure in general, the following Examples describe some additional embodiments, features, and attributes of this disclosure. While embodiments of this disclosure are described in connection with the following examples and the corresponding text and figures, there is no intent to limit embodiments of this disclosureto this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of embodiments of this disclosure. The following examples are put forth to provide those of ordinary skill in the art with a complete disclosure and description of how to perform the methods and use the technology disclosed and claimed herein. Efforts have been made to ensure accuracy with respect to numbers (for example, amounts, temperature, etc.), but some errors and deviations should be accounted for.

[0083] LEV flow control systems and methods for aircraft flight control and maneuvering will now be discussed in more detail with reference to Figures 1-4. Figure 1 is a plan view of a tailless aircraft 100 having a blended-body lambda wing 102 incorporating a flow control system for flight control and maneuvering. Figure 2 is a block diagram depicting an aircraft flight control system 200 to control forces and moments on aircraft. Figure 3 as a block flow diagram depicting an aircraft flight control method 300 to control forces and moments on aircraft. Figure 4 depicts a computing machine 2000 and a module 2050, which will be discussed in further detail near the end of this description.

[0084] Referring now to Figure 1, the system for controlling leading-edge vortex (LEV) flow and liftoff on aircraft is illustrated. The wing 102 is depicted with various labeled components and directional arrows for understanding the airflow dynamics and force vectors involved in the system

[0085] Locations SI to S10 indicate positions of pneumatic jet actuators, such as supersonic jets (SSJs) 104, on the wing 102 that influence the LEV. Figure 1 depicts five SSJs 104 (as a representation) at locations S1-S5 on a left side of the wing 102 and five SSJs 104 at locations S6-S10 on a right side of the wing 102. The SSJs 104 at locations S1-S10 are positioned near the crank in the wing 102 denoted by the change in angle of the leading edge of the wing 102. As the crank effects LEV liftoff, locating the SSJs 104 at locations S1-S10 in the vicinity of the crank increases the effectiveness of the SSJs 104.

[0086] Although depicted as ten SSJs 104 in Figure 1, any suitable number of SSJs may be utilized. For example, one, two, or any desired number of SSJs 104 may be utilized on each side of the wing. A single SSJ 104 may be suitable for desired performance. For example, on each side of the wing, a single SSJ 104 with a fixed output direction, or a single SSJ 104 having a variable output within a 0-360 degree range, may be located near the wing crank, or at another suitable location, to improve the wing’s performance. Alternatively, multiple SSJs 104 may be utilized to increase the effective area of jet interaction of the flow over the wing.

[0087] Each of the SSJs 104 at locations S 1-10 may incorporate desired characteristics for the location / airflow. For example, each of the SSJs 104 may have a variable output within a 0-360 degree range. Alternatively, each of the SSJs 104 at locations S1-S5, and locations S6-S10, may have different, fixed directional outputs, and the system may select which of the SSJs 104 to activate to provide a jet output in a desired direction. Or, each of the SSJs 104 at locations S1-S5 and locations S6-S10 may comprise a number of SSJs 104 that each have different, fixed directional outputs, and the system may select which of the SSJs 104 at a particular location (e.g., locations corresponding to SSJs 104 at locations S1-S10) to activate to provide a jet output in a desired direction and from a desired location.

[0088] One, fewer than five, or more than five SSJs 104 may be utilized on each side of the wing 102, and disposed at a selected location, to provide the desired effects. For example, a single SSJ 104 may be utilized at location S2 and a single SSJ 104 may be utilized at location S9. These single SSJs 104 may have a variable output within a 0-360 degree range, may have a fixed directional output, or may include multiple SSJs with different, fixed directional outputs.

[0089] The arrows labeled A, B, C, and D in Figure 1 indicate different directions, representing movement, airflow, or force vectors that interact with the wing’s surface. These directions are for understanding how the system manipulates the LEV to achieve desired aerodynamic effects, such as pitch, roll, or yaw control / moments. The aircraft 100 moves in flight in the direction A. Accordingly, air flows over the wing 102 in the direction B. The SSJs output jets of air in various directions For example, as shown in Figure 1, SSJ S3 is outputting a jet in a direction C of 350° relative to the flight path, while SSJ S8 is outputting a jet in a direction D of 135° relative to the flight path. In this case, the jet output in the direction C includes a vector component in the direction A of the flight path (against the direction B of the airflow), and the jet output in the direction D includes a vector component against the direction A of the flight path (in the direction B of the airflow).

[0090] The compass roses showing the beta symbol with angles (e.g., representative angles 0°, 90°, 180°, 270°, 350°, 135°) indicate jet output direction in relation to the aircraft flight direction A and the inboard section of each side of the wing 102. Zero degrees indicates the direction A of flight, 90° indicates a direction perpendicular to the direction A toward the inboard section of the wing 102, 180° indicates the direction B of airflow over the wing 102 that is opposite to the flight direction A, and 270° indicates a direction perpendicular to thedirection A toward the outboard section of the wing 102. This orientation is for modulating the aerodynamic forces and moments on the aircraft.

[0091] The design depicted in Figure 1, with its labeled components and directional indicators, aligns with actively controlling the LEV to enhance aircraft maneuverability. The SSJs 104, positioned at strategic locations on the wing, can be activated in specified directions and amount of activation to influence the LEV’S flow, thereby achieving the desired flight attitude. This setup is particularly relevant for tailless aircraft with swept wings, where traditional control surfaces may be less effective or less desirable.

[0092] Figure 1 illustrates how the system determines the amount of SSJ activation needed to influence the LEV flow over the wing. By adjusting the orientation and amount of activation of the SSJs 104, the system can delay or alter the liftoff of the LEV, control the periodicity of secondary vortices, and ultimately modulate the aircraft’s aerodynamic performance. The interaction between the labeled components and the directional arrows highlights the system’s capability to achieve control over the aircraft’s flight dynamics.

[0093] SSJs 104 described herein may be installed in a wing in any suitable manner. For example, the nozzle for an SSJ may be coupled to the surface of a wing, or the nozzle for an SSJ may be recessed in the surface of the wing to reduce drag. In either case, the nozzle can be coupled to the wing in any suitable manner, such as by welding or mechanical connection, such as a nut / bolt type system, rivets, or other suitable connection.

[0094] Other components of the SSJ are installed inside the aircraft, for example, inside the wing, fuselage, or other aircraft structure. Multiple sources exist for the source of the power on which the actuators rely. Compressed air can be bled from the engine, or a dedicated small (micro) compressor can be provided for each actuator or subset of actuators. For small jet outputs, each SSJ 104 may have a micro-compressor that supplies the compressed air, or individual micro-compressors may supply compressed air to multiple SSJs 104. Supply lines, power, processors / controllers, plenums, compressors, and any other components can be mounted to the aircraft in any suitable manner, such as by welding or with suitable fasteners, such as bolts, rivets, brackets, etc., with the corresponding nozzle positioned to dispense its output along the exterior surface of the wing in a desired direction relative to the leading edge of the wing or the airflow over the wing.

[0095] Figure 2 is a block diagram depicting an aircraft flight control system 200 to control forces and moments on aircraft. The flight control system 200 comprises a storage device 204, a processor 202 communicatively coupled to the storage device 204, and one or more SSJs 104coupled to the processor 202. The processor 202 executes application code instructions that are stored in the storage device 204 to cause the system 200 to control moments and forces on aircraft. For example, the processor 202 receives control inputs for flight attitude(s) from a peripheral device, such as a flight controller 208 coupled to an input device (for example, a control stick 210 in the aircraft or at a control station controlling the aircraft). The flight controller 208 inputs indicate a desired force in pitch, roll, and / or yaw, or change therein, for the aircraft. The processor 202 also receives status inputs from other aircraft systems, sensors, or components 212 indicating airspeed, angle of attack, altitude, bank angle, local airflow over the wing, or other suitable inputs. The processor 202 determines, based on the control inputs and the status inputs, an amount of SSJ activation to execute the desired flight attitude and communicates instructions to one more SSJs 104 to activate for a specified time, in a specified direction, and with a specified amount of activation. At each instructed SSJ 104, an SSJ controller 206a receives the instructions, controls the SSJ 104 to turn its amount of activation in the specified direction (or controls the SSJ oriented in a fixed direction as specified) based on the received instructions, and activates the SSJ 104 for the specified time and with the specified level of activation based on the received instructions.

[0096] In certain examples, the SSJs 104 may have a fixed orientation. In this case, the processor 202 determines, based on the control inputs and the status inputs, an amount of SSJ activation to execute the desired flight attitude and communicates instructions to one more SSJs 104 to activate for a specified time and with a specified amount of activation. At each instructed SSJ 104, the SSJ controller 206a receives the instructions, and activates the SSJ 104 for the specified time and with the specified amount of activation based on the received instructions.

[0097] In certain examples, the SSJs 104 may also have a fixed amount of activation output. In this case, the processor 202 determines, based on the control inputs and the status inputs, an amount of SSJ activation to execute the desired flight attitude and communicates instructions to one more SSJs 104 to activate for a specified time. At each instructed SSJ 104, the SSJ controller 206a receives the instructions, and activates the SSJ 104 for the specified time to output the fixed level of activation based on the received instructions.

[0098] Each SSJ 104 may have an individual controller 206a, or one or more controllers 206a may control multiple SSJs 104. In this manner, the processor 202 determines one or more forces and / or moments needed to provide the desired flight attitude, based on the control inputs and the status inputs, and communicates instructions to the SSJs 104 to activate to provide thedetermined forces and / or moments to the aircraft. In response, the SSJs execute the received instructions and activate accordingly to provide the determined forces and / or moments to the aircraft.

[0099] The processer 202 determines, based on the control inputs and the status inputs, the number and location of SSJs 104 to activate. As described herein, SSJs 104 that are activated can provide more or less moment or force based on the location of the activated SSJ 104 on the wing. In this manner, based on the desired amount of control, the processor 202 may determine to active one or multiple SSJs 104.

[0100] The processor 202 also can control conventional aircraft control surfaces, such as rudder, elevator, and ailerons, or other surfaces, to control the aircraft based on the control inputs and the status inputs.

[0101] All components of the flight control system may be installed in an aircraft. Alternatively, certain components may be installed in the aircraft, while other components are located remote to the aircraft, with communications between the components occurring over a network. For example, the SSJs 104 and the aircraft systems, sensors, and components may be installed on the aircraft, and the remaining components may be located remote to the aircraft.

[0102] Although being described herein as being disposed on an upper surface of the wing, the SSJs may be disposed on any suitable location on the wing, such as a lower surface or edges (if applicable) of the wing.

[0103] In summary, the processor 202 is communicatively coupled to the storage device 204. The processor 202 executes application code instructions stored in the storage device 204 to process control inputs received from the control stick 210 via the flight controller 208. These control inputs indicate desired changes in pitch, roll, and yaw for the aircraft.

[0104] The processor 202 also receives status inputs from various aircraft systems, sensors, and components 212, which provide real-time data, such as airspeed, angle of attack, angle of incidence, altitude, and local airflow over the wing. Based on these inputs, the processor 202 determines the necessary activation of the SSJs 104 to influence the flow of the LEV over the wing. The processor 202 then communicates specific control instructions to the SSJ controllers 206, which manage the activation of the SSJs for a specified time, direction, and amount of activation to achieve the desired flight attitude. This design provides a flow of information and control commands, enabling manipulation of the LEV to maintain or alter the aircraft’s flight path.

[0105] The functionality of each component forms the system’s operation. The control stick 210 allows for manual input of flight commands, while the flight controller 208 processes these inputs into a format usable by the processor 202. The processor 202’ s role is to analyze both control and status inputs to determine the optimal SSJ 104 activation strategy. The SSJ controllers 206 execute these strategies by controlling the SSJs 104, which directly affect the LEV’S behavior, thereby influencing the aircraft’s aerodynamic performance. This interaction between components highlights the system’s capability to adjust to changing flight conditions, ensuring stability and control of the aircraft.

[0106] Thus, Figure 2 depicts a system designed to enhance aircraft maneuverability through active flow control, utilizing a network of interconnected components to achieve control over the leading-edge vortex dynamics.

[0107] Figure 3 illustrates a flowchart depicting a method 300 for controlling leading-edge vortex (LEV) flow and lift-off on aircraft. The method 300 outlines a systematic approach to manage aerodynamic forces and moments through active flow control techniques. This process is for achieving desired flight attitudes by manipulating the LEV over the wing using SSJs.

[0108] The method 300 begins with step 305, which involves the processor 202 receiving control inputs for a flight attitude. These inputs are for determining the desired maneuvers in pitch, roll, and yaw and / or lift at trimmed pitch. The control inputs may originate from a peripheral device, such as the flight controller 208, and indicate the necessary adjustments to achieve the desired flight dynamics. This step is for setting the initial conditions for the subsequent operations in the method 300.

[0109] In step 310, the processor also receives status inputs from various aircraft systems, sensors, or components 212. These inputs provide real-time data on parameters such as airspeed, angle of incidence, angle or attack, altitude, and local airflow over the wing. The integration of these status inputs is for accurately assessing the current flight conditions and determining the appropriate SSJ 104 activation required to influence the LEV flow effectively. This step allows the system to adapt to changing flight conditions and maintain optimal control over the aircraft’s aerodynamic performance.

[0110] In step 315, the method 300 further includes the processor 202 determining the amount of SSJ activation needed to influence the LEV flow. This determination involves calculating the specific activation parameters, such as the duration, direction, and amount of activation of the SSJs 104, to achieve the desired flight attitude. For example, the specific activationparameters are calculated to achieve a desired pitch, roll, or yaw moment to thereby provide the desired flight attitude or change.[OHl] The processor 202 then communicates instructions to the SSJs 104, as outlined in step 320, ensuring precise control over the LEV dynamics. The instructions include commands to one more SSJs 104 to activate for the specified time, in a specified direction, and with a specified amount of activation to achieve the desired flight attitude.

[0112] Finally, step 325 involves SSJ controller(s) 206 receive the instructions and activate the SSJs 104 based on the received instructions, completing the method 300 for controlling the LEV flow and liftoff on the aircraft.

[0113] Thus, Figure 3 provides an overview of the method 300 for controlling LEV flow and liftoff, highlighting the integration of control and status inputs to achieve precise aerodynamic control through SSJ activation. The method 300 is designed to enhance the maneuverability and stability of aircraft, particularly those with advanced wing configurations, by actively managing the LEV dynamics.

[0114] The technology described herein is not limited to a supersonic jet, and any suitable jet or jet actuator may be utilized. Additionally, a single jet, or a combination of two or more jets disposed relative to the LEV liftoff location (or locations) and flow directions can be utilized to provide the desired LEV flow control and flutter control at any desired portion of the flight envelope. For example, at a given airspeed and angle of incidence, a jet having a configured velocity and volume of air can be utilized to reduce or eliminate the LEV liftoff. The jet velocity and volume can be configured to provide desired flight characteristic results, and multiple jets can be utilized at locations along the wing. The jet output can be provided continuously, and the velocity and volume can be varied throughout the flight envelope to provide the desired flight characteristics. The jet output also can be provided intermittently as desired to provide the desired flight characteristics at various locations in the flight envelope. Both sides of a wing on an aircraft can include the flow control mechanisms, which can be operated simultaneously the same or independently, as desired.

[0115] For example, to produce a desired pitching moment, corresponding jets on both sides of the wing may be activated simultaneously and in the same amount and / or direction; and to produce a desired rolling or yawing moment, corresponding jets on both sides of the wing may be activated simultaneously in different amounts and / or directions (and / or jets in different locations on opposition sides of the wing (e.g., S1-S5 and S6-S10) may be activated simultaneously in different amounts and / or directions).Test Examples

[0116] Experiments using a modular flat-top lambda wing with a sharp leading edge revealed that the LEV consists of two counter-rotating vortices. The primary vortex on the right side of the wing is large, counterclockwise-rotating, and attached to the separated shear layer. A small, clockwise (negative) rotating secondary vortex is located near the wing surface, situated between the shear layer and the primary vortex. Although smaller in size, this secondary vortex has a comparable vorticity concentration to the primary. It forms due to the upward velocity induced by the primary vortex and the entrainment of the shear layer, which pulls fluid toward the surface separation line. The secondary vortex plays a role in maintaining the equilibrium and stability of the LEV structure.

[0117] An Active Flow Control (AFC) actuator jet, such as an SSJ or other suitable nozzle, is disposed the wing’s top surface, for example, in a circular plug. The jet’s nozzle may be capable of 360° j et rotation to control directional output. Alternatively, multiple nozzles having fixed directional output may be used to select the directional output. This enables more precise manipulation of the LEV without altering the wing geometry. The nozzle output modifies the LEV structure through interaction with the jet. Figures 5a-5c are plots of streamlines showing the effect of jet orientation on the LEV structure. At a station z / b ~ 0.65 normal to the LE produces a baseline LEV structure without jet actuation. The corresponding baseline streamlines of the structure are plotted in Figure 5b. When the actuator (located at z / b « 0.54) is oriented at P = 350° (plotted in Figure 5a), the jet blows towards the secondary vortical structure of the LEV and energizes both the LEV structures by strengthening the vorticity magnitude of the primary and the secondary vortex, increasing the aspect ratio of the LEV. This generated the largest nose-down pitching moment for this configuration. Conversely, rotating the jet to = 150° (plotted in Figure 5c) opposes the primary vortex, disrupting its development and breaking it into multiple weaker vortical structures, with a corresponding large negative vorticity region. This configuration results in a slight nose-up pitching moment.

[0118] The effect of the actuation depends on the jet orientation (P), the lift coefficient (CL) which in turn is dependent on the angle of attack (a), and other geometric parameters like the aspect ratio (AR) and the LE sweep angle (A) of both the inner and outer wing constituting the overall design, leading to different crank angles.

[0119] Figures 6a-6b show the effect of Aspect Ratio (AR) on the LEV structure and pitch moment due to actuation (ACLM) dependence on the jet orientation (P) for (a) a short outerwing with an AR=2.34 and (b) a longer outer wing with an AR=3.9, at Crank angle of 0° (i.e., a straight leading edge wing). The pitch moment coefficient (CLM) for various lift coefficients (CL) was used to quantify the effect of jet orientation, for two configurations with the same inner wing but varying size of the outer wing, thus changing the wing aspect ratio (AR). The zero level indicates no effect of the jet on CLM, whereas negative ACLM indicates nose down pitch moment effect, and positive ACLM indicates nose up pitch moment effect.

[0120] Actuation on the smaller outer wing configuration (AR=2.34) generates a nose down pitching moment with the maximum CLM~ -0.009 for (3=270° at CL=0.4 compared to — 0.025 for AR=3 9 with a relatively larger outer wing, at the same actuator orientation p and CL values. Barely notable nose-up moment of CL ~ 0.001 was generated for p=120° at CL=0.5 at the smaller AR=2.34 wing, but considerable CLM~0.025 was generated when the AR was increased to AR=3.9 for the same at CL=0.4. This exemplifies the effect of outer wing sizing on the pitch moment behavior due to AFC with otherwise constant geometrical parameters. AFC approaches described herein may be used in multi-disciplinary aircraft design optimization, but also may be used to improve the performance of an existing aircraft design.

[0121] Graphing this data is useful to determine preferred jet orientations for achieving desired aerodynamic effects, such as controlling the leading-edge vortex (LEV) and influencing the aircraft’s pitch, roll, and yaw moments. The ability to adjust the jet orientation to achieve specific pitch moment coefficient (CL ) values at different lift coefficients can enhance the aircraft’s maneuverability and stability, particularly in tailless aircraft designs with swept wings or delta configurations. The graph serves as a visual tool for engineers to fine-tune the active flow control system, ensuring that the aircraft maintains desired flight attitudes under varying aerodynamic conditions.

[0122] Figures 6a and 6b illustrate two graphs that depict the relationship between the pitching moment coefficient (CLM) and the jet orientation angle (P) for two distinct wing configurations. Graph (a) represents a configuration with a short outer wing having an aspect ratio (AR) of 2.34, while Graph (b) corresponds to the original outer wing with an AR of 3.9, at Crank angle of 0°. Both graphs plot CLM on the Y-axis and P on the X-axis, showcasing how the pitch moment varies with changes in jet orientation and lift coefficient (CL).

[0123] In Graph (a), the data for the short outer wing configuration with AR=2.34 shows a relatively stable pitch moment across different jet orientations, with slight variations observed at different lift coefficients (CL=0.2, 0.3, 0.4, and 0.5). The curves indicate that the pitch moment remains close to zero, with minor fluctuations as the jet orientation changes. Thissuggests that the short outer wing configuration may offer little pitching moment benefit across various jet orientations

[0124] Conversely, graph (b) for the original outer wing with AR=3.9 demonstrates more pronounced variations in the pitch moment coefficient as the jet orientation changes. The data for lift coefficients CL=0.2, 0.3, and 0.4 reveal significant fluctuations, particularly at certain jet orientations. For instance, at P angles around 120° and 240°, the pitch moment exhibits notable peaks and troughs, indicating that the original outer wing configuration may experience more dynamic changes in pitch moment with varying jet orientations. This behavior suggests that the original outer wing configuration provides substantial pitching moment benefits.

[0125] The comparison between the two graphs highlights the impact of aspect ratio and wing configuration on the pitch moment behavior in response to jet orientation. The short outer wing with a lower aspect ratio appears to offer little room for pitch control, while the original outer wing with a higher aspect ratio shows greater sensitivity to changes in jet orientation. This analysis aligns with improving and / or optimizing aerodynamic control through wing design and strategic jet orientation to maximize the benefit of AFC. Aerodynamic control also may be improved and / or optimized for existing wing designs through strategic jet orientation to maximize the benefit of AFC on such existing designs.

[0126] The crank angle between the inner and outer wing may affect the number and characteristics of LEVs developing and hence the pitch moment. Figure 7 shows the pitch moment due to actuation (ACLM) dependence on the jet orientation ( ) for a longer outer wing with an AR=3.9 at a crank angle of 30°. The modular wing design enabled changing the outer wing’s sweep angle (Aouter) that changed also the crank angle, thus permitting investigation of the crank angle effect on the flow. When the AOuter= 30°, the crank angle representing the difference between the sweep angle of the inner and outer wing is 30°. The same inner wing actuator generated nose-down pitching moment peaking at CLM~ -0.006 at p=270°, and a large nose-up pitch peaking at CLM~ 0.014 at P=360° (representing blowing against the freestream) was obtained. Subsequent investigations were conducted at P=330° to ensure that the jet doesn’t oscillate between inboard and outboard directions. Other investigations were conducted probing the flow with a variety of experimental techniques comparing the effect of crank angles, including a comparison between a sharp leading edge configuration and a blunt leading edge A'Eept wzng / low Zest model (SWiFT) having the same planform shape.

[0127] Particle Image Velocimetry (PIV) was performed at several planes parallel to the wing’s flat-top surface, at various distances away from the wing. These results onceinterpolated provide a volumetric perspective of the flow. For a=10°, velocity parallel to the surface normalized by freestream velocity (Vx / Uco) shows the formation and evolution of the LEV from the wing-root with high Vxmagnitudes until it reaches the crank (x / c -0.67) for the baseline flow. The slow moving flow downstream (x / c >0.67) is part of vortex lift-off, where due to low axial momentum the structure separates and lifts-off from the surface. LEV lift-off is better visualized when looking at a plane normal to the wing surface oriented along the LEV core axis, Ainner.core- 68°. The LEV core is represented by high Vxmagnitudes which decelerate to stagnation (Vx=0), and even recirculation, when traveling downstream. LEV lift-off is a dynamic process resulting in unsteady loads on the wing, leading to flutter or buffet, which is not desirable. Another LEV forms over the outer wing starting from the crank, proceeding along its LE until it is being engulfed by the tip flow.

[0128] Actuation at p=270° (in outboard direction normal to the free stream) energizes the primary vortex of the inner wing LEV, thus providing axial momentum to the vortical fluid resulting in an extension of high Vxmagnitudes almost until the trailing edge (TE). This subsequently reduces the vortex lift-off Vxmagnitude and size of the low momentum fluid within the probed volume, effectively delaying the LEV lift-off process. A larger region of higher Vxmagnitude flow (higher suction pressure) downstream of the pitch moment reference line (MRP at x / c=0.51) results in a nose-down pitching moment. The actuator’s spanwise location coinciding with the region where Vxtransitions from high-speed to low-speed flow improves the performance. Actuation at this angle has minimal effect on the outer wing LEV.

[0129] Whereas actuation at P=330° increases the angular momentum thus increasing the swirl ratio inadvertently promoting the vortex lift-off. Local flow is accelerated but doesn’t affect the transition location of high speed to low-speed flow. In turn, it intensifies the recirculation in the post lift-off flow. The local velocity near the actuator increases, but the lifted-off vortex is more intense. Actuation negatively impacts the outer wing LEV due to its interaction with the inner wing LEV hampering its development. The combined loss of suction pressure due to intense low-speed flow in the lifted-off vortex, and the regression of the outer wing LEV- results in a nose-up pitch scenario.

[0130] These results provide evidence that active flow control (AFC) by a single steady jet located at a strategic geometric location and oriented relative to the free stream (either through nozzle rotation, a single nozzle oriented in the desired direction, or multiple, selectable nozzles with various directional outputs) may generate sufficient pitching moment capable of controlling an aircraft. This effect is achieved by affecting the path and the structure of theleading edge vortex. Further, a change in the outer wing sweep and size influences the pitching moment resulting from AFC. Integrating AFC at the conceptual aircraft design stage by using a multi-disciplinary optimization approach may be more effective, but adding AFC may also be used to improve the performance of a frozen design. The strategic location is generally relative to the wing crank, such as a location near the crank or just outside of the crank. The strategic location depends upon the wing design and may be identified for each particular design.

[0131] Experiments revealed that the LEV consists of two counter-rotating vortices: A primary vortex - large, counterclockwise-rotating, attached to the separated shear layer; and a secondary vortex - small, clockwise-rotating, located near the wing surface. The research demonstrates that although smaller, the secondary vortex has comparable vorticity concentration to the primary vortex and plays a role in maintaining the equilibrium and stability of the LEV structure.

[0132] Jet orientation can alter the leading-edge vortex (LEV) structure, affecting the aerodynamic performance of the wing. Jet orientation affects the flow over a wing, highlighting the influence of Active Flow Control (AFC) at different angles. Compare three scenarios: AFC at 0=270°, a baseline (BL) without actuation, and AFC at 0=330°, for the flat-top lambda wing with a sharp leading edge with crank of 30°

[0133] In the first scenario (a), AFC at 0=270 shows a distinct flow pattern, with the jet energizing the primary vortex, thereby extending the high-velocity region almost to the trailing edge. This configuration results in a nose-down pitching moment due to the increased axial momentum of the vortical fluid. The baseline scenario (b) without actuation reveals a more stable flow pattern, with a noticeable lift-off of the vortex downstream, indicating a natural separation process. In contrast, the AFC at 0=330° (c) disrupts the primary vortex, promoting vortex lift-off and resulting in a nose-up pitching moment. This configuration intensifies recirculation in the post lift-off flow, as evidenced by the larger negative vorticity region.

[0134] Vx / Uoo (axial velocity parallel to the wing surface normalized by freestream velocity) provides a measure of the velocity changes induced by the different jet orientations. The AFC at 0=270° enhances the flow’s axial momentum, while the AFC at 0=330° increases the swirl ratio, inadvertently promoting vortex lift-off. These variations in flow dynamics underscore the role of jet orientation in controlling the LEV structure and, consequently, the aerodynamic forces and moments on the wing. The ability to manipulate these parameters through AFCoffers a tool for optimizing aircraft performance, particularly in tailless and swept-wing configurations.

[0135] The impact of Active Flow Control (AFC) on the leading-edge vortex (LEV) structure at different jet orientations, specifically P=270° and P=330°, was compared to a baseline (BL) scenario without actuation. Plots can display the velocity component Vxnormalized by the freestream velocity (LLo) across the X and Z axes, providing a visual representation of how the LEV structure is influenced by the AFC.

[0136] For AFC P=270°, the AFC enhances the primary vortex, effectively delaying the LEV lift-off. Regions show increased velocity and vorticity concentration, suggesting a more stable vortex structure. A Mean Reference Point (MRP) serves as a reference for comparing the effects of different jet orientations.

[0137] The BL represents the baseline scenario without any AFC. Here, the LEV structure is less defined, with a baseline flow path. The absence of AFC results in a more dispersed vortex structure, with a broader distribution of velocity magnitudes.

[0138] For AFC P=330°, the AFC increases the angular momentum of the vortex, promoting lift-off. Regions are more concentrated, indicating a stronger vortex that is more prone to liftoff. This configuration results in a dynamic change in the LEV structure, as the increased angular momentum affects the stability and path of the vortex.

[0139] The scale for the velocity component Vx / U«> ranges from -0.5e-02 to 1.4e+00. This scale helps in interpreting the intensity and distribution of the velocity across the different scenarios. The AFC at p=270° and p=330° demonstrates the capability of AFC to modulate the LEV structure, either stabilizing it or promoting lift-off, depending on the desired aerodynamic effect. The strategic use of AFC can thus be employed to control the aerodynamic forces and moments on aircraft.LEV Path and Structure Control Tests

[0140] The flow over a straight (crank 0°) and a cranked (crank 30°) lambda wing planform having a flat upper surface, and a sharp leading edge was investigated experimentally, using flow visualization and particle image velocimetry, while measuring the forces and moments on the model using a five-component force balance. The result indicated that the path and structure of an LEV can be controlled by a jet output relative to a specified direction. A single, small steady jet - a point source of momentum - located just inboard of the crank provided the wing with nose up or down pitch control authority and enabled the wing to be trimmed at high anglesof incidence. To achieve this result, the jet was rotated at various angles relative to the oncoming free stream therefore disrupting the feedback mechanism existing between the primary leading-edge vortex and the separated shear layer that feeds it with vorticity. The experiments were carried out in a low-speed wind tunnel at 25 m / s therefore providing a Reynolds number of approximately 1.2 x 106and a Mach number smaller than 0.1.

[0141] A steady SSJ blowing at total output of 2g / s corresponding to Cfj.,. ft=2C2013, at various angles relative to the free stream, 0, affected the pitching moment in both directions relative to the trimmed baseline condition, thus providing longitudinal control for such a planform. The dependence of the pitch on the blowing angle is given in Figure 6a, where it transpired that blowing inboard, perpendicular to the root chord (0=90°) generated the highest pitch-up, while blowing outboard at 0=270° generated the highest pitch down or most negative CLM. The sensitivity of the nose down pitch to variations in 0 was high, particularly in the range of 210°< 0<27O°, while the sensitivity of the nose up pitch was negligible in the range of 60°< 0<12O°. It is interesting to note that the pitch control authority for the mass flow used increased with lift coefficient provided CL< 0.4.

[0142] Blowing outboard at 0=270° (i.e., perpendicular to the free stream direction) generated a large nose-down pitching moment up to CL =0.42, thus increasing the possibility of a trimmed flight by more than 60% at the maximum jet mass flow selected. At a=8°, the nose down pitch obtained by this blowing reached CLM= -0.026, while rotating the jet to 0=120° resulted in nose up pitch of CLM = +0.013. These values would enable an airplane to maneuver in pitch without the use of movable control surfaces. Oil flow analysis corresponding to the blowing at 0=270° suggests that the j et increased the strength of the secondary vortex, thus pushing the creation of the new LEV toward the wingtip that also shrank the region of the reverse flow. Plotted vorticity contours revealed that the blowing at 0=270° strengthened the primary and the secondary vortex and increased the inclination angle of the shear layer relative to the surface, thus pushing the entire LEV system toward the LE of the outer wing. Blowing at 0=120° weakened the main vortex pushing it in the chordwise direction toward the wake region. Vorticity contours indicate that the core of the main vortex is downstream of the outer wing with a weakened and flattened secondary vorticity, and an increase in the inclination of the shear layer. This enabled the secondary separation line to continue along the span and reach the tip of the outer wing. It might have created a small LEV outboard of the jet’ s nozzle that followed the secondary separation line to the tip. To verify the existence of the patternsobserved, another oil flow visualization using different ingredients was initiated and the patterns were reproduced.

[0143] The secondary vortex spans the entire chord of the outer wing for the baseline flow and its maximum dimensionless vorticity is 60 units. Blowing at P=120° diminished its strength to 20 units and reduced its extent in the vertical and chordwise directions. It strengthened the vorticity in the separated shear layer while weakening the core of the main vortex and reducing its vertical extent. Blowing at p=270° had an opposite effect on the inner secondary vortex whose maximum dimensionless vorticity was increased to 80 units. The main vortex changed its shape and extended much further from the surface when compared to the baseline main vortex.

[0144] Introducing a 30° crank to the outer wing while maintaining the same wingspan and tip orientation affected the baseline flow and with it the forces and moments acting on the wing. The planform of this cranked model was identical to the planform of the Swept Wing Flow Test model (SWiFT), thus enabling one to assess the added effects of SWiFT’s variable thickness, LE radius, and outwash angles. The lift attained by the cranked model differed little from the straight LE lift discussed in the absence of a crank. There is a break in the lift slope around a ~ 8° where dClJda decreased from approximately 0.06 to 0.045. It is interesting to note that at a > 10°, dCi / da oscillates wildly and concomitantly the nose up pitch departure occurs. These may be indicators for unsteadiness and for local flow separation.

[0145] The same single jet that was used in the absence of crank, originated inboard of the crank and consumed a mass flow of 2g / s changed the pitch characteristics of this cranked wing as well. Blowing outboard at p=270° generated a nose-down CLM = -0.007 that was approximately 1 / 3 of the nose down generated in the absence of the crank. However, it enabled trimming the wing up to CL=0.82 by simply increasing the mass flow up to 2g / s while in the absence of the crank the trimming authority of the jet reached only a CL=0.45. Percentagewise, the improvement in both cases was almost identical. The crank changed the sensitivity of the pitch to P, making the nose-up pitch sensitive to the angle of injection while the nose down pitch was insensitive to P in the range of 90°< p < 300°.

[0146] Oil flow visualization and vorticity contours were measured by PIV at a=10°, in addition to the dependence of the pitching moment on CLshown. The crank created a new LEV whose dimensionless vorticity, in the plane parallel with the trailing edge of the inboard wing and being normal to the wing’s surface, was measured by PIV. This new LEV took the role ofthe shear layer that interacted with the primary vortex emanating from the apex on the inboard side while receiving vorticity from the separated shear layer on its outboard side. Its maximum vorticity is an order of magnitude higher than that of the inboard vortex, at that location. It therefore pulled the secondary separation line of the inboard vortex toward it.

[0147] The model could be trimmed up to a=10° without actuation and provide a CL=0.48. To trim the model at CL=0.65 corresponding to a=14° a mass flow of m = 2g / s is required at 0=270°. At this a, the inner vortex secondary separation bends outboard and joins the outboard vortex secondary separation, thus allowing the fluid within the inboard vortex to be entrained by the outer wing vortex. The surface flow between the LE of the outer wing and the secondary separation of its vortex appears to be sluggish and the reversed flow zone at its TE was enlarged when compared with the pattern generated at a=10°.

[0148] The effect of the jet on the vorticity contours on the cranked wing is quite like its effect in absence of the crank. Blowing at 0=270° stretches the inboard vortex in the y-direction (away from the surface) and enhances its vorticity near the shear layer or near the crank-generated new vortex on the outer wing. The stretch in the y-direction is so large that it was even observed by the smoke when the latter was illuminated by a laser sheet. The secondary vortical structure possessing the negative vorticity is enhanced and pushed outward. The two LEVs are distinct with the secondary vorticity between them.

[0149] Blowing at 0=330° on the cranked wing and blowing at 0=120° in the absence of crank virtually eliminated the secondary vortex with its negative vorticity, bringing the two corotating vortices together in the presence of the crank, while stretching the single vortex inboard in the absence of the crank. In both cases, nose-up pitch was achieved. The most effective nose down pitch was also achieved at the same angle of blowing, irrespective of the crank.

[0150] The flow over a generic lambda wing having a sharp leading edge (LE) and a fixed sweep back angle of its inner part was investigated experimentally for two crank angles of the outer wing, while the inner wing’s sweep-back angle was fixed at 60°. The forces and moments acting on this configuration are dominated by the LEVs. It transpired that a LEV consists of three major components: a shear layer that feeds the primary vortex with its angular momentum and vorticity, the primary vortex, and a secondary vortical structure that returns some fluid trapped inside the reattaching to the shear layer, thus providing a feedback loop between the primary vortex and its source of angular momentum. Disrupting that loop by manipulating the ratio of momenta of the inner wing primary vortex affects the vortex strength and its interior composition that results in changes of pressure distribution and affects the pitching moment.A single jet was able to either increase or decrease the pitching moment experienced by the wing, by simply changing its orientation. It can therefore augment the effectiveness or even replace a traditional moving control surface on thin swept-back wings.

[0151] A more in-depth discussion of controlling the path and structure of an LEV by a small jet is provided in H. Kalyankar, A. H. P. Noel, U. Urreiztieta, L. Taubert, and I. Wygnanski, “On Controlling the Path & Structure of a Leading-Edge Vortex by a Single, Small Jet,” AIAA 2025-1450, NATO AVT-350 Task Group, AIAA SciTech Forum and Exposition 2025, January 2025, the entire contents of which are hereby fully incorporated herein by reference.Testing Discrete Jets for Control of Moments on Tailless Aircraft

[0152] A study was conducted to replace the traditional control surfaces on a tailless aircraft model called the Swept Wing Flow Test model (SWiFT) by Active Flow Control (AFC). The model was designed in the UK under the auspices of NATO’s Advanced Vehicle Technology program. Wind tunnel tests focused on the maintenance of trim at high lift coefficients using a single supersonic jet emanating from a small nozzle at an appropriate location and orientation relative to the free stream. The pitch trimmed lift coefficient was tripled even though the AFC parameters were not systematically optimized. To understand the effect of AFC on the flow over such a wing, flow visualization and Particle Image Velocimetry (PIV) were used. Proper Orthogonal Decomposition applied to this data revealed unsteady behavior in the leading-edge vortex lift-off and its advection over the outer wing that was effectively subdued by AFC, thus extending the range of incidence angles that could be flown. Exploratory tests revealed that AFC can provide yaw and roll required for aircraft maneuver.

[0153] Tests were carried out on the Swept Wing Flow Test model, dabbed as the SWiFT, at the Arizona Low Speed Wind Tunnel. The model’s outer mold was designed in the UK by J. Coppin. It represents a generic blended wing configuration of a tailless aircraft that was also tested at the National Transonic Facility at NASA. The tests were carried out at Reynolds number Re=1.66xl06based on the root chord, and they included various AFC configurations consisting of SJAs and SSJs. Forces and moments were measured in addition to flow visualization. The flow was also probed by hot wires and Particle Image Velocimetry (PIV). Proper Orthogonal Decomposition (POD) was used to explore the unsteadiness encountered with the separation of the LEV and its possible contribution to flutter.

[0154] Figure 8 includes cross-sectional and plan views of the SWIFT model design of a wing 802 depicting various design parameters and features. Figure 8 also depicts locations L7-L14on the leading edge of the wing 802 at which various nozzles were located for testing. Such nozzles includes sweeping jet actuators (SJAs) and supersonic jets (SSJs).

[0155] In order to assess the significance of actuation location on the flow, different pairs of small (0.050”x0.080”) SJA and SSJ actuators were calibrated and used on the model. Figure 9 depicts graphs showing the effect of location of a pair of Sweeping Jet Actuators (SJAs), disposed normal to the LE, on pitch (CLM), yaw (CLN), and roll (CLL) moments using nij =3.5 g / s. Figure 10 depicts graphs showing the effect of location of a pair of SSJs, disposed normal to the LE, on CLM, CLN, and CLL using approximately the same power that was used in conjunction with the SJA results shown in Figure 9. Figure 11 depicts graphs showing the effect of changing the jet orientation of a single SSJ located at approximately location S9 of Figure 1 (location L9 of Figure 8) on CL , CLN, and CLL using irij=2 g / s.

[0156] The introduction of actuation near the LE of the outer wing 802 prevented the generation of the spanwise flow near its TE, thus avoiding previous nose-up pitch departure. At a=12° and mass flow nij=2 g / s (CL —0.65), as a representative data, there is a strong spanwise flow in the crank region inboard of the first actuator at location L9 in Figure 8. It is most probably responsible for the nose-up pitch trend that is strengthened with increase of blowing velocity. This trend is exacerbated by the disappearance of the LEV from the outer wing due to the acceleration of the surface flow upstream of the actuators. At a=14°, a separation focus becomes visible near the LE of the crank, and the surface spanwise flow that is so prominently visible near the TE of the crank region at a=12° disappeared at a=14°. Both effects are associated with the nose-down pitch trend. At ot=16° (CL =0.8), the separation focus moved upstream of the mean rotation point and became much larger, suggesting that the LEV on the inboard wing is stronger, thus resuming the nose-up pitch departure trend with increasing a. The introduction of SSJs, whose direction and average rate of spread is much more confined, resulted in more moderate nose-up and nose-down pitch departures.

[0157] The pitch dependence on CL for approximately identical power consumed is plotted for the SJAs in Figure 9 and for the SSJs in Figure 10, and it is compared to the trimmed condition of the baseline model. The baseline model retained its trim up to CL = 0.25 with a nose up pitch departure beyond it. The use of 2 SJAs located near the tip (locations L13-L14 in Figure 8) enabled the maintenance of trim up to CL = 0.6 provided the nij was adjusted for every a, but not exceeding nij = 3.5g / s. Using the inboard actuators slightly increased the trim capabilities provided the actuation was on the outboard wing (locations L9-L10 and L10-L11 in Figure 8),but the blowing required for trim at lower incidence angles depended on the location selected. However, actuation near the crank (locations L9-L10 in Figure 8) resulted in large pitch reversals at CL >0.7. Actuation inboard of the crank (locations L7-L8 in Figure 8) was much less effective limiting the trim capability for the prescribed maximum mass flow to CL ~ 0.45 (Figure 9). The use of this AFC method on a single outer wing could provide a yawing moment of CLN = -0.02 up to CL= 0.6, that generated a rolling moment, CLL= -0.05.

[0158] SSJs of identical nozzle dimensions and using comparable power were less effective in controlling the trim than the SJAs (Figure 9). However, they were more sensitive to the jet locations with the best results being achieved from blowing on the outer wing near the crank (locations L9-L10 in Figure 8). The SSJs did not create large pitch reversals at CL > 0.7 even when applied near the crank, but its largest advantage is the creation of a large yaw without the associated roll.

[0159] It was suspected that the sensitivity of the two SSJs’ actuators to location stems from the orientation of their jets relative to the local flow, and that sensitivity is blurred by the wide sweep angles of the SJAs. Since the most effective pitch control by an SSJ was obtained just outboard of the crank, a single SSJ at location L9 in Figure 8 was tested to assess the flow’s sensitivity to varying jet orientation. The results shown in Figure 11 indicate that a jet whose axis is oriented inboard between 15° < / > < 195° provides the best pitch control that enables trim up to CL=0.57. The configuration also provided favorable yaw and roll moments as shown in Figure 11.

[0160] The addition of AFC to wing design involves many independent variables that interact closely with the conventional wing-design parameters, such as thickness, camber, aspect ratio, sweepback, and taper. In this test campaign, only the AFC variables were changed at various angles of incidence and the flow was probed using force balance, smoke and oil visualization, hot wire anemometry and PIV. Balance measurements indicated that trimmed lift could be increased by two-fold when a single supersonic jet located outboard of the LE crank and oriented inboard at 150° relative to the freestream was introduced. Asymmetric application of AFC could create yaw at acceptable roll. This data confirms the relationship of jet orientation, location, and velocity in addition to its mass flow that was often used to estimate the magnitude of the momentum input.

[0161] Since the SWIFT model has a 30° LE crank that precipitated the liftoff of the LEV from the wing’s surface at moderately low incidence that changed abruptly the trend in the pitching moment behavior, the flow was probed in the crank’s vicinity with and without the applicationof AFC. It helped to assess the combined effect of the crank and the AFC on the LE vortex flow, its path over the outer wing, and its separation from the wing’s surface. It transpired that the mean flow is oriented outboard almost parallel to the LE of the outer wing at a=14°, but it oscillates violently between downstream and upstream oriented directions. These oscillations result in buffet that could be detected on the model even at low freestream speeds. AFC attached the flow and maintained its downstream direction while preventing the detachment of fluid from the main LEV that originated near the wing root.

[0162] The current tests demonstrated the richness of the parameter space involved on the AFC design side, although the wing design was frozen. It concludes that even a single small supersonic jet that is located and oriented properly on the wing can have sufficient control authority to replace conventional control surfaces. The jet area relative to the plane’s planform area is of the order of 10-5, suggesting that AFC may replace some complex control surfaces very effectively.

[0163] A more in-depth discussion on the use of discrete jets for control of moments on tailless aircraft is provided in H. Kalyankar, J. Pompe, L. Taubert, and I. Wygnanski, “On the Use of Discrete Jets for Control of Moments on Tailless Aircraft,” AIAA AVIATION FORUM AND ASCEND 2024, July 2024, the entire contents of which are hereby fully incorporated herein by reference.

[0164] As described herein, an SSJ can be oriented on the wing to expel a jet of air in a specified direction. The direction and amount of activation (such as time and force) can be selected to provide desired pitch, yaw, and rolling moments, or a change in lift at trimmed pitch of an aircraft to which the wing is attached. The direction of an expelled jet is measured with regard to the direction of flight and towards the inboard section of the wing, as described previously with reference to Figure 1. Depending on the desired direction and amount of pitch, yaw, and / or rolling moment, or a change in lift at trimmed pitch, desirable results were achieved with various directions for the expelled air within the range of 0° to 360°, about 15° to about 195°, about 210° to about 270°, about 90° to about 300°, about 60° to about 120°, including all angles in those ranges and specifically 0 / 360°, 90°, 120°, 150°, 180°, 240°, 270°, 330°, 350°, 135°.

[0165] Although described mainly herein as SSJs, any suitable pneumatic jet actuator may be utilized that expels a desired amount / force of air in a desired direction.Systems and Methods to Control Leading-edge Vortex Flow and Liftoff on Aircraft

[0166] Described in certain example embodiments herein are systems and methods to control leading-edge vortex flow and liftoff on aircraft, including tailless aircraft, as shown and described herein.

[0167] Clause 1. A system to control leading-edge vortex flow and liftoff on aircraft, comprising: at least one supersonic jet (SSJ) disposed on a surface of a wing; a storage device; and a processor communicatively coupled to the storage device, wherein the processor executes application code instructions that are stored in the storage device to cause the system to: receive control inputs for a flight attitude from a peripheral device, the control inputs indicating a desired force in pitch, roll, and / or yaw, lift at trimmed pitch, or change therein, for the aircraft; receive status inputs from aircraft systems, sensors, or components indicating airspeed, angle of incidence, altitude, bank angle, local airflow over the wing, or other suitable inputs; determine, based on the control inputs and the status inputs, an amount of SSJ activation to influence flow of a leading-edge vortex (LEV) over the wing to execute the desired flight attitude; and communicate instructions to one more SSJs to activate for a specified time, in a specified direction, and with a specified amount of activation to achieve the desired flight attitude.

[0168] Clause 2. The system of clause 1, wherein the peripheral device is a flight controller

[0169] Clause 3. The system of clause 1, wherein for each instructed SSJ, an SSJ controller receives the instructions and activates the SSJ for the specified time and with the specified amount of activation.

[0170] Clause 4. The system of clause 1, wherein for each instructed SSJ, an SSJ controller receives the instructions, controls the SSJ to turn its amount of activation in the specified direction, and activates the SSJ for the specified time and with the specified amount of activation.

[0171] Clause 5. The system of clause 1, wherein the at least one SSJ comprises a plurality of SSJs, each of the SSJs configured to expel a jet of air in a different direction with respect to the other SSJs, and wherein determining an amount of SSJ activation comprises determining at least one of the SSJs to activate based on the desired direction of expelled air.

[0172] Clause 6. The system of clause 5, wherein the at least one SSJ comprises a plurality of SSJs disposed on a left side of the wing and a plurality of SSJs disposed on a right side of the wing, and wherein determining an amount of SSJ activation comprises determining at least oneof the SSJs to activate on the left side of the wing and at least one of the SSJs to activate on the right side of the wing.

[0173] Clause 7. The system of clause 6, wherein the at least one SSJ activated on the left side of the wing expels air with a vector component in a direction of air flowing over the wing, and the at least one SSJ activated on the right side of the wing expels air with a vector component in a direction opposite to air flowing over the wing.

[0174] Clause 8. The system of clause 1, wherein the specified direction is angled with respect to a direction of travel of the wing through air.

[0175] Clause 9. The system of clause 8, wherein the specified direction includes at least a vector component that is in the direction of travel of the wing through air.

[0176] Clause 10. The system of clause 1, further comprising an air source that provides compressed air to the at least one SSJ.

[0177] Clause 11. The system of clause 1, wherein the air source comprises a compressor.

[0178] Clause 12. A system to control leading-edge vortex flow and liftoff on aircraft, comprising: a wing; and at least one supersonic jet (SSJ) disposed on a surface of the wing relative to a location of liftoff of a leading-edge vortex (LEV) generated over the wing, the at least one SSJ being oriented such that a jet output from the at least one SSJ influences flow of the LEV over the wing.

[0179] Clause 13. The system of clause 12, wherein the jet output from the at least one SSJ influences the flow of the LEV by promoting or delaying liftoff of the LEV from the wing.

[0180] Clause 14 The system of clause 12, wherein the jet output from the at least one SSJ influences the flow of the LEV by changing a location on the wing where liftoff of the LEV occurs.

[0181] Clause 15 The system of clause 12, wherein the jet output from the at least one SSJ influences the flow of the LEV by controlling the interaction of multiple LEVs generated over the wing.

[0182] Clause 16. The system of clause 12, wherein the at least one SSJ outputs the jet at an angle with respect to a direction of travel of the wing through air.

[0183] Clause 17. The system of clause 16, wherein the at least one SSJ outputs the jet with at least a vector component that is in the direction of travel of the wing through air.

[0184] Clause 18. The system of clause 12, wherein the jet output from the at least one SSJ is pulsed in relation to a periodicity of liftoff of the LEV from the wing to influence flow of the LEV over the wing.

[0185] Clause 19. The system of clause 12, wherein the at least one SSJ comprises a single SSJ.

[0186] Clause 20. The system of clause 12, wherein the at least one SSJ comprises a plurality of SSJs.

[0187] Clause 21. The system of clause 12, wherein the at least one SSJ comprises a plurality of SSJs that are activatable individually or in groups of two or more.

[0188] Clause 22. The system of clause 12, wherein the at least one SSJ comprises a plurality of SSJs, and wherein less than all of the SSJs are activated at the same time.

[0189] Clause 23. The system of clause 12, wherein the at least one SSJ comprises a plurality of SSJs, and only one of the SSJs is activated at a time.

[0190] Clause 24. The system of clause 12, wherein the at least one SSJ comprises a plurality of SSJs, and a different one or more of the SSJs is activated to provide a desired control depending on an attitude of the aircraft to which the wing is attached.

[0191] Clause 25. The system of clause 12, wherein the at least one SSJ comprises a plurality of SSJs on a left side of the wing and a plurality of SSJs on a right side of the wing, and wherein at least one SSJ on the left side of the wing and at least one SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0192] Clause 26. The system of clause 12, wherein the at least one SSJ comprises a single SSJ on a left side of the wing and a single SSJ on a right side of the wing, and wherein the SSJ on the left side of the wing and the SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0193] Clause 27. The system of clause 12, further comprising an aircraft to which the wing is attached.

[0194] Clause 28. The system of clause 27, wherein the aircraft is a tailless aircraft.

[0195] Clause 29. The system of clause 27, wherein the wing comprises a swept back wing.

[0196] Clause 30. The system of clause 29, wherein the wing comprises a crank, and wherein the at least one SSJ is positioned relative to the crank where liftoff of the LEV occurs.

[0197] Clause 31. The system of clause 12, wherein the jet output from the SSJ is angled within a range of about 0° to about 360° with respect a direction of flight of the wing.

[0198] Clause 32. The system of clause 12, wherein the jet output from the SSJ is angled within a range of about 15° to about 195° degrees with respect to a direction of flight of the wing.

[0199] Clause 33. The system of clause 12, wherein the jet output from the SSJ is angled about 15°, about 60°, about 105°, about 150°, or about 195° with respect to a direction of flight of the wing.

[0200] Clause 34. A method to control leading-edge vortex flow and liftoff on aircraft, comprising: providing a wing; providing at least one air jet disposed on an upper surface of the wing relative to a location of liftoff of a leading-edge vortex (LEV) generated over the wing, the at least one air jet being oriented such that a jet of air output from the at least one air jet influences flow of the LEV over the wing; and expelling a jet of air from the at least one air jet.

[0201] Clause 35. The method of clause 34, wherein the at least one air jet comprises a pneumatic jet actuator.

[0202] Clause 36. The method of clause 35, wherein the pneumatic jet actuator comprises one of a supersonic jet or a sweeping jet actuator.

[0203] Clause 37. The method of clause 34, wherein the jet of air output from the at least one air jet influences the flow of the LEV by promoting or delaying liftoff of the LEV from the wing.

[0204] Clause 38. The method of clause 34, wherein the jet of air output from the at least one air jet influences the flow of the LEV by changing a location on the wing where liftoff of the LEV occurs.

[0205] Clause 39. The method of clause 34, wherein the jet of air output from the at least one air jet influences the flow of the LEV by controlling the interaction of multiple LEVs generated over the wing.

[0206] Clause 40. The method of clause 34, wherein the at least one SSJ outputs the jet at an angle with respect to a direction of travel of the wing through air.

[0207] Clause 41. The method of clause 34, wherein the at least one SSJ outputs the jet with a vector component that is in the direction of travel of the wing through air.

[0208] Clause 42. The method of clause 34, wherein the jet of air output from the at least one air jet is pulsed in relation to a periodicity of liftoff of the LEV from the wing to influence flow of the LEV over the wing.

[0209] Clause 43. The method of clause 34, wherein the at least one air jet comprises a single air jet.

[0210] Clause 44. The method of clause 34, wherein the at least one air jet comprises a plurality of air jets.

[0211] Clause 45. The method of clause 34, wherein the at least one air jet comprises a plurality of supersonic jets (SSJs) on a left side of the wing and a plurality of SSJs on a right side of the wing, and wherein an air jet is expelled from at least one SSJ on the left side of the wing and at least one SSJ on the right side of the wing to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0212] Clause 46. The method of clause 45, wherein the air jet expelled from the at least one SSJ on the left side of the wing includes a vector component in a direction of travel of the wing through the air and the air jet expelled from the at least one SSJ on the right side of the wing includes a vector component that is opposite to the direction of travel of the wing through the air.

[0213] Clause 47. The method of clause 34, wherein the provided at least one air jet comprises a supersonic jet (SSJ) on a left side of the wing and an SSJ on a right side of the wing, and wherein the SSJ on the left side of the wing and the SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

[0214] Clause 48. The method of clause 47, wherein the SSJ on the left side of the wing and the SSJ on a right side of the wing expel air in different directions relative to a flow of air over the wing.

[0215] Clause 49. The method of clause 34, further comprising providing an aircraft to which the wing is attached.

[0216] Clause 50. The method of clause 34, wherein the provided wing comprises a swept back wing comprising a crank, and wherein the at least one air jet is positioned relative to the crank where liftoff of the LEV occurs.

[0217] Clause 51. The method of clause 34, wherein the provided wing includes a swept back wing, and wherein the at least one pulsating air jet is positioned close to the apex of the wing.

[0218] Clause 52. A system to control leading-edge vortex flow and liftoff on aircraft as shown and described.

[0219] Clause 53. A method to control leading-edge vortex flow and liftoff on aircraft as shown and described.

[0220] Clause 54. A flight control system to control leading-edge vortex flow and liftoff on aircraft as shown and described.Other Example Embodiments

[0221] Figure 4, referenced previously, depicts a computing machine 2000 and a module 2050 in accordance with certain example embodiments. The computing machine 2000 may correspond to any of the various computers, servers, mobile devices, embedded systems, or computing systems presented herein. The module 2050 may comprise one or more hardware or software elements configured to facilitate the computing machine 2000 in performing the various methods and processing functions presented herein. The computing machine 2000 may include various internal or attached components such as a processor 2010, system bus 2020, system memory 2030, storage media 2040, input / output interface 2060, and a network interface 2070 for communicating with a network 2080.

[0222] The computing machine 2000 may be implemented as a conventional computer system, an embedded controller, a laptop, a server, a mobile device, a smartphone, a set-top box, a kiosk, a router or other network node, a vehicular information system, one or more processors associated with a television, a customized machine, any other hardware platform, or any combination or multiplicity thereof. The computing machine 2000 may be a distributed system configured to function using multiple computing machines interconnected via a data network or bus system.

[0223] The processor 2010 may be configured to execute code or instructions to perform the operations and functionality described herein, manage request flow and address mappings, and to perform calculations and generate commands. The processor 2010 may be configured to monitor and control the operation of the components in the computing machine 2000. The processor 2010 may be a general-purpose processor, a processor core, a multiprocessor, a reconfigurable processor, a microcontroller, a digital signal processor (“DSP”), an application specific integrated circuit (“ASIC”), a graphics processing unit (“GPU”), a field programmable gate array (“FPGA”), a programmable logic device (“PLD”), a controller, a state machine, gated logic, discrete hardware components, any other processing unit, or any combination or multiplicity thereof. The processor 2010 may be a single processing unit, multiple processing units, a single processing core, multiple processing cores, special purpose processing cores, co-processors, or any combination thereof. According to certain embodiments, the processor 2010 along with other components of the computing machine 2000 may be a virtualized computing machine executing within one or more other computing machines.

[0224] The system memory 2030 may include non-volatile memories such as read-only memory (“ROM”), programmable read-only memory (“PROM”), erasable programmable31read-only memory (“EPROM”), flash memory, or any other device capable of storing program instructions or data with or without applied power. The system memory 2030 may also include volatile memories such as random access memory (“RAM”), static random access memory (“SRAM”), dynamic random access memory (“DRAM”), and synchronous dynamic random access memory (“SDRAM’). Other types of RAM also may be used to implement the system memory 2030. The system memory 2030 may be implemented using a single memory module or multiple memory modules. While the system memory 2030 is depicted as being part of the computing machine 2000, one skilled in the art will recognize that the system memory 2030 may be separate from the computing machine 2000 without departing from the scope of the subject technology. It should also be appreciated that the system memory 2030 may include, or operate in conjunction with, a non-volatile storage device such as the storage media 2040.

[0225] The storage media 2040 may include a hard disk, a floppy disk, a compact disc read only memory (“CD-ROM”), a digital versatile disc (“DVD”), a Blu-ray disc, a magnetic tape, a flash memory, other non-volatile memory device, a solid state drive (“SSD”), any magnetic storage device, any optical storage device, any electrical storage device, any semiconductor storage device, any physical-based storage device, any other data storage device, or any combination or multiplicity thereof. The storage media 2040 may store one or more operating systems, application programs and program modules such as module 2050, data, or any other information. The storage media 2040 may be part of, or connected to, the computing machine 2000. The storage media 2040 may also be part of one or more other computing machines that are in communication with the computing machine 2000 such as servers, database servers, cloud storage, network attached storage, and so forth.

[0226] The module 2050 may comprise one or more hardware or software elements configured to facilitate the computing machine 2000 with performing the various methods and processing functions presented herein. The module 2050 may include one or more sequences of instructions stored as software or firmware in association with the system memory 2030, the storage media 2040, or both. The storage media 2040 may therefore represent examples of machine or computer readable media on which instructions or code may be stored for execution by the processor 2010. Machine or computer readable media may generally refer to any medium or media used to provide instructions to the processor 2010. Such machine or computer readable media associated with the module 2050 may comprise a computer software product. It should be appreciated that a computer software product comprising the module 2050 may also be associated with one or more processes or methods for delivering the module 2050to the computing machine 2000 via the network 2080, any signal-bearing medium, or any other communication or delivery technology. The module 2050 may also comprise hardware circuits or information for configuring hardware circuits such as microcode or configuration information for an FPGA or other PLD.

[0227] The input / output (“I / O”) interface 2060 may be configured to couple to one or more external devices, to receive data from the one or more external devices, and to send data to the one or more external devices. Such external devices along with the various internal devices may also be known as peripheral devices. The I / O interface 2060 may include both electrical and physical connections for operably coupling the various peripheral devices to the computing machine 2000 or the processor 2010. The I / O interface 2060 may be configured to communicate data, addresses, and control signals between the peripheral devices, the computing machine 2000, or the processor 2010. The I / O interface 2060 may be configured to implement any standard interface, such as small computer system interface (“SCSI”), serial- attached SCSI (“SAS”), fiber channel, peripheral component interconnect (“PCI”), PCI express (PCIe), serial bus, parallel bus, advanced technology attached (“ATA”), serial ATA (“SATA”), universal serial bus (“USB”), Thunderbolt, FireWire, various video buses, and the like. The I / O interface 2060 may be configured to implement only one interface or bus technology. Alternatively, the VO interface 2060 may be configured to implement multiple interfaces or bus technologies. The I / O interface 2060 may be configured as part of, all of, or to operate in conjunction with, the system bus 2020. The I / O interface 2060 may include one or more buffers for buffering transmissions between one or more external devices, internal devices, the computing machine 2000, or the processor 2010.

[0228] The I / O interface 2060 may couple the computing machine 2000 to various input devices including mice, touchscreens, scanners, electronic digitizers, sensors, receivers, touchpads, trackballs, cameras, microphones, keyboards, any other pointing devices, or any combinations thereof. The I / O interface 2060 may couple the computing machine 2000 to various output devices including video displays, speakers, printers, projectors, tactile feedback devices, automation control, robotic components, actuators, motors, fans, solenoids, valves, pumps, transmitters, signal emitters, lights, and so forth.

[0229] The computing machine 2000 may operate in a networked environment using logical connections through the network interface 2070 to one or more other systems or computing machines across the network 2080. The network 2080 may include wide area networks (W AN), local area networks (LAN), intranets, the Internet, wireless access networks, wired networks,mobile networks, telephone networks, optical networks, or combinations thereof. The network 2080 may be packet switched, circuit switched, of any topology, and may use any communication protocol. Communication links within the network 2080 may involve various digital or an analog communication media such as fiber optic cables, free-space optics, waveguides, electrical conductors, wireless links, antennas, radio-frequency communications, and so forth.

[0230] The processor 2010 may be connected to the other elements of the computing machine 2000 or the various peripherals discussed herein through the system bus 2020. It should be appreciated that the system bus 2020 may be within the processor 2010, outside the processor 2010, or both. According to certain example embodiments, any of the processor 2010, the other elements of the computing machine 2000, or the various peripherals discussed herein may be integrated into a single device such as a system on chip (“SOC”), system on package (“SOP”), or ASIC device.

[0231] In situations in which the systems discussed here collect personal information about users, or may make use of personal information, the users may be provided with an opportunity or option to control whether programs or features collect user information (e.g., information about a user’s social network, social actions or activities, profession, a user’s preferences, or a user’s current location), or to control whether and / or how to receive content from the content server that may be more relevant to the user. In addition, certain data may be treated in one or more ways before it is stored or used, so that personally identifiable information is removed. For example, a user’ s identity may be treated so that no personally identifiable information can be determined for the user, or a user’s geographic location may be generalized where location information is obtained (such as to a city, ZIP code, or state level), so that a particular location of a user cannot be determined. Thus, the user may have control over how information is collected about the user and used by a content server.

[0232] Embodiments may comprise a computer program that embodies the functions described and illustrated herein, wherein the computer program is implemented in a computer system that comprises instructions stored in a machine-readable medium and a processor that executes the instructions. However, it should be apparent that there could be many different ways of implementing embodiments in computer programming, and the embodiments should not be construed as limited to any one set of computer program instructions. Further, a skilled programmer would be able to write such a computer program to implement an embodiment of the disclosed embodiments based on the appended flow charts and associated description inthe application text. Therefore, disclosure of a particular set of program code instructions is not considered necessary for an adequate understanding of how to make and use embodiments. Further, those skilled in the art will appreciate that one or more aspects of embodiments described herein may be performed by hardware, software, or a combination thereof, as may be embodied in one or more computing systems. Moreover, any reference to an act being performed by a computer should not be construed as being performed by a single computer as more than one computer may perform the act.

[0233] The example embodiments described herein can be used with computer hardware and software that perform the methods and processing functions described herein. The systems, methods, and procedures described herein can be embodied in a programmable computer, computer-executable software, or digital circuitry. The software can be stored on computer- readable media. For example, computer-readable media can include a floppy disk, RAM, ROM, hard disk, removable media, flash memory, memory stick, optical media, magnetooptical media, CD-ROM, etc. Digital circuitry can include integrated circuits, gate arrays, building block logic, field programmable gate arrays (FPGA), etc.General Disclosures

[0234] While embodiments of this disclosure are described in connection with examples and the corresponding text and figures, there is no intent to limit embodiments of this disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of embodiments of this disclosure. The examples described herein are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the invention claimed herein. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for.

[0235] It is to be understood that this disclosure is not limited to the particular embodiments described, and as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0236] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described hereincan also be used in the practice or testing of this disclosure, certain methods and materials are now described.

[0237] All publications and patents cited in this specification are cited to disclose and describe the methods and / or materials in connection with which the publications are cited. The complete disclosure of all such publications and patents are herein incorporated by references as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. Such incorporation by reference is expressly limited to the methods and / or materials described in the cited publications and patents and does not extend to any lexicographical definitions from the cited publications and patents. Any lexicographical definition in the publications and patents cited that is not also expressly repeated in this application should not be treated as such and should not be read as defining any terms appearing in the accompanying claims. The citation of any publication is for its disclosure prior to the filing date and should not be construed as an admission that this disclosure is not entitled to antedate such publication by virtue of prior disclosure. Further, the dates of publication provided could be different from the actual publication dates that may need to be independently confirmed.

[0238] As will be apparent to those of ordinary skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other described embodiments without departing from the scope or spirit of this disclosure. Any recited method can be carried out in the order of events recited or in any other order that is logically possible.

[0239] Where a range is expressed, a further aspect includes from the one particular value and / or to the other particular value. Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure. For example, where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g., the phrase “x to y” includes the range from ‘x’to ‘y’ as well as the range greater than ‘x’ and less than ‘y’. The range can also be expressed as an upper limit, e.g., ‘about x, y, z, or less’ and should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of Tess than x’, less than y’, and Tess than z’ . Likewise, the phrase ‘about x, y, z, or greater’ should be interpreted to include the specific ranges of ‘about x’, ‘about y’, and ‘about z’ as well as the ranges of ‘greater than x’, greater than y’, and ‘greater than z’. In addition, the phrase “about ‘x’ to ‘y’”, where ‘x’ and ‘y’ are numerical values, includes “about ‘x’ to about ‘y’”.

[0240] It should be noted that ratios, amounts, and other numerical data can be expressed herein in a range format. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that a number of values are disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms a further aspect. For example, if the value “about 10” is disclosed, then “10” is also disclosed.

[0241] It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range, as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 30 to 135” should be interpreted to include not only the explicitly recited values of about 30 to about 135, but also include individual values (e.g., about 30, about 31, about 32, etc.) and the sub-ranges (e g., about 30 to about 45, about 60 to about 70, etc. and other possible sub-ranges) within the indicated range.

[0242] As used herein, the singular forms “a,” “an,” and “the” include both singular and plural referents unless the context clearly dictates otherwise.

[0243] As used herein, “about,” “approximately,” “substantially,” and the like, when used in connection with a measurable variable such as a parameter, an amount, a temporal duration, and the like, are meant to encompass variations of and from the specified value including those within experimental error (which can be determined by, e.g., a given data set, art accepted standard, and / or with, e.g., a given confidence interval (e.g., 90%, 95%, or more confidence interval from the mean), such as variations of + / -10% or less, + / -5% or less, + / -!% or less, and+ / -0.1% or less of and from the specified value, insofar such variations are appropriate to perform in the disclosed invention. As used herein, the terms “about,” “approximate,” “at or about,” and “substantially” can mean that the amount or value in question can be the exact value or a value that provides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error, and the like, and other factors known to those of ordinary skill in the art such that equivalent results or effects are obtained. In some circumstances, the value that provides equivalent results or effects cannot be reasonably determined. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about,” “approximate,” or “at or about” whether or not expressly stated to be such. It is understood that where “about,” “approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0244] The term “optional” or “optionally” means that the subsequent described event, circumstance, or substituent may or may not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0245] The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within the respective ranges, as well as the recited endpoints.

[0246] Various embodiments are described herein. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment(s). Reference throughout this specification to “one embodiment,” “an embodiment,” “an example embodiment,” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention described herein. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” or “an example embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner, as would be apparent to a person having ordinary skill in the art from this disclosure, in one or more embodiments. Additionally, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be withinthe scope of the invention. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0247] The complete disclosure of all publications, published patent documents, and patent applications cited herein is hereby fully incorporated by reference to the same extent as though each individual publication, published patent document, or patent application was specifically and individually indicated as being incorporated by reference.

[0248] The example systems, methods, and acts described in the embodiments presented previously are illustrative, and, in alternative embodiments, certain acts can be performed in a different order, in parallel with one another, omitted entirely, and / or combined between different example embodiments, and / or certain additional acts can be performed, without departing from the scope and spirit of various embodiments. Accordingly, such alternative embodiments are included in the scope of the following claims, which are to be accorded the broadest interpretation so as to encompass such alternate embodiments.

[0249] Various modifications and variations of the inventions described herein will be apparent to those having ordinary skill in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific embodiments, it will be understood that it is capable of further modifications and that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those having ordinary skill in the art are intended to be within the scope of the invention. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from this disclosure that come within known customary practice within the art to which the invention pertains and may be applied to the essential features herein before described.

Claims

CLAIMSWhat is claimed is:

1. A system to control leading-edge vortex flow and liftoff on aircraft, comprising: at least one supersonic jet (S S J) disposed on a surface of a wing; a storage device; and a processor communicatively coupled to the storage device, wherein the processor executes application code instructions that are stored in the storage device to cause the system to: receive control inputs for a flight attitude from a peripheral device, the control inputs indicating a desired force in pitch, roll, and / or yaw, lift at trimmed pitch, or change therein, for the aircraft; receive status inputs from aircraft systems, sensors, or components indicating airspeed, angle of incidence, altitude, bank angle, local airflow over the wing, or other suitable inputs; determine, based on the control inputs and the status inputs, an amount of SSJ activation to influence flow of a leading-edge vortex (LEV) over the wing to execute the desired flight attitude; and communicate instructions to one more SSJs to activate for a specified time, in a specified direction, and with a specified amount of activation to achieve the desired flight attitude.

2. The system of claim 1, wherein the peripheral device is a flight controller.

3. The system of claim 1, wherein for each instructed SSJ, an SSJ controller receives the instructions and activates the SSJ for the specified time and with the specified amount of activation.

4. The system of claim 1, wherein for each instructed SSJ, an SSJ controller receives the instructions, controls the SSJ to turn its amount of activation in the specified direction, and activates the SSJ for the specified time and with the specified amount of activation.

5. The system of claim 1, wherein the at least one SSJ comprises a plurality of SSJs, each of the SSJs configured to expel a jet of air in a different direction with respect to the other SSJs, and wherein determining an amount of SSJ activation comprises determining at least one of the SSJs to activate based on the desired direction of expelled air.

6. The system of claim 5, wherein the at least one SSJ comprises a plurality of SSJs disposed on a left side of the wing and a plurality of SSJs disposed on a right side of the wing, and wherein determining an amount of SSJ activation comprises determining at least one of the SSJs to activate on the left side of the wing and at least one of the SSJs to activate on the right side of the wing.

7. The system of claim 6, wherein the at least one SSJ activated on the left side of the wing expels air with a vector component in a direction of air flowing over the wing, and the at least one SSJ activated on the right side of the wing expels air with a vector component in a direction opposite to air flowing over the wing.

8. The system of claim 1, wherein the specified direction is angled with respect to a direction of travel of the wing through air.

9. The system of claim 8, wherein the specified direction includes at least a vector component that is in the direction of travel of the wing through air.

10. The system of claim 1, further comprising an air source that provides compressed air to the at least one SSJ.

11. The system of claim 1, wherein the air source comprises a compressor.

12. A system to control leading-edge vortex flow and liftoff on aircraft, comprising: a wing; and at least one supersonic jet (SSJ) disposed on a surface of the wing relative to a location of liftoff of a leading-edge vortex (LEV) generated over the wing, the at least one SSJ being oriented such that a jet output from the at least one SSJ influences flow of the LEV over the wing.

13. The system of claim 12, wherein the jet output from the at least one SSJ influences the flow of the LEV by promoting or delaying liftoff of the LEV from the wing.

14. The system of claim 12, wherein the jet output from the at least one SSJ influences the flow of the LEV by changing a location on the wing where liftoff of the LEV occurs.

15. The system of claim 12, wherein the jet output from the at least one SSJ influences the flow of the LEV by controlling the interaction of multiple LEVs generated over the wing.

16. The system of claim 12, wherein the at least one SSJ outputs the jet at an angle with respect to a direction of travel of the wing through air17. The system of claim 16, wherein the at least one SSJ outputs the jet with at least a vector component that is in the direction of travel of the wing through air.

18. The system of claim 12, wherein the jet output from the at least one SSJ is pulsed in relation to a periodicity of liftoff of the LEV from the wing to influence flow of the LEV over the wing.

19. The system of claim 12, wherein the at least one SSJ comprises a single SSJ.

20. The system of claim 12, wherein the at least one SSJ comprises a plurality of SSJs.

21. The system of claim 12, wherein the at least one SSJ comprises a plurality of SSJs that are activatable individually or in groups of two or more.

22. The system of claim 12, wherein the at least one SSJ comprises a plurality of SSJs, and wherein less than all of the SSJs are activated at the same time.

23. The system of claim 12, wherein the at least one SSJ comprises a plurality of SSJs, and only one of the SSJs is activated at a time.

24. The system of claim 12, wherein the at least one SSJ comprises a plurality of SSJs, and a different one or more of the SSJs is activated to provide a desired control depending on an attitude of the aircraft to which the wing is attached.

25. The system of claim 12, wherein the at least one SSJ comprises a plurality of SSJs on a left side of the wing and a plurality of SSJs on a right side of the wing, and wherein at least one SSJ on the left side of the wing and at least one SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

26. The system of claim 12, wherein the at least one SSJ comprises a single SSJ on a left side of the wing and a single SSJ on a right side of the wing, and wherein the SSJ on the left side of the wing and the SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

27. The system of claim 12, further comprising an aircraft to which the wing is attached.

28. The system of claim 27, wherein the aircraft is a tailless aircraft.

29. The system of claim 27, wherein the wing comprises a swept back wing.

30. The system of claim 29, wherein the wing comprises a crank, and wherein the at least one SSJ is positioned relative to the crank where liftoff of the LEV occurs.

31. The system of claim 12, wherein the jet output from the SSJ is angled within a range of about 0° to about 360° with respect a direction of flight of the wing.

32. The system of claim 12, wherein the jet output from the SSJ is angled within a range of about 15° to about 195° degrees with respect to a direction of flight of the wing.

33. The system of claim 12, wherein the jet output from the SSJ is angled about 15°, about 60°, about 105°, about 150°, or about 195° with respect to a direction of flight of the wing.

34. A method to control leading-edge vortex flow and liftoff on aircraft, comprising: providing a wing; providing at least one air jet disposed on an upper surface of the wing relative to a location of liftoff of a leading-edge vortex (LEV) generated over the wing, the at least one air jet being oriented such that a jet of air output from the at least one air jet influences flow of the LEV over the wing; and expelling a jet of air from the at least one air jet.

35. The method of claim 34, wherein the at least one air jet comprises a pneumatic jet actuator.

36. The method of claim 35, wherein the pneumatic jet actuator comprises one of a supersonic jet or a sweeping jet actuator.

37. The method of claim 34, wherein the jet of air output from the at least one air jet influences the flow of the LEV by promoting or delaying liftoff of the LEV from the wing.

38. The method of claim 34, wherein the jet of air output from the at least one air jet influences the flow of the LEV by changing a location on the wing where liftoff of the LEV occurs.

39. The method of claim 34, wherein the jet of air output from the at least one air jet influences the flow of the LEV by controlling the interaction of multiple LEVs generated over the wing.

40. The method of claim 34, wherein the at least one SSJ outputs the jet at an angle with respect to a direction of travel of the wing through air.

41. The method of claim 34, wherein the at least one SSJ outputs the jet with a vector component that is in the direction of travel of the wing through air.

42. The method of claim 34, wherein the jet of air output from the at least one air jet is pulsed in relation to a periodicity of liftoff of the LEV from the wing to influence flow of the LEV over the wing.

43. The method of claim 34, wherein the at least one air jet comprises a single air jet.

44. The method of claim 34, wherein the at least one air jet comprises a plurality of air jets.

45. The method of claim 34, wherein the at least one air jet comprises a plurality of supersonic jets (SSJs) on a left side of the wing and a plurality of SSJs on a right side of the wing, and wherein an air jet is expelled from at least one SSJ on the left side of the wing and at least one SSJ on the right side of the wing to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

46. The method of claim 45, wherein the air jet expelled from the at least one SSJ on the left side of the wing includes a vector component in a direction of travel of the wing through the air and the air jet expelled from the at least one SSJ on the right side of the wing includes a vector component that is opposite to the direction of travel of the wing through the air.

47. The method of claim 34, wherein the provided at least one air jet comprises a supersonic jet (SSJ) on a left side of the wing and an SSJ on a right side of the wing, and wherein the SSJ on the left side of the wing and the SSJ on the right side of the wing are activated to produce at least one of a rolling moment, a yaw moment, a pitching moment, or a change in lift at trimmed pitch of an aircraft to which the wing is attached.

48. The method of claim 47, wherein the SSJ on the left side of the wing and the SSJ on a right side of the wing expel air in different directions relative to a flow of air over the wing.

49. The method of claim 34, further comprising providing an aircraft to which the wing is attached.

50. The method of claim 34, wherein the provided wing comprises a swept back wing comprising a crank, and wherein the at least one air jet is positioned relative to the crank where liftoff of the LEV occurs.

51. The method of claim 34, wherein the provided wing includes a swept back wing, and wherein the at least one pulsating air jet is positioned close to the apex of the wing.

52. A system to control leading-edge vortex flow and liftoff on aircraft as shown and described.

53. A method to control leading-edge vortex flow and liftoff on aircraft as shown and described.

54. A flight control system to control leading-edge vortex flow and liftoff on aircraft as shown and described.

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