A method for enhancing the maneuverability of a flying wing aircraft using a fluidic propulsion system

Abstract

The application belongs to the field of aircraft overall design, propulsion system, aerodynamic layout design and flight control, and particularly relates to a jet propulsion system and a method for enhancing the dynamic control capability of a flying wing aircraft, wherein the jet propellers are symmetrically installed on the left wing and the right wing of the aircraft; the thrust control device is used for receiving the thrust instruction sent by the control system and controlling the thrust size of the jet propeller; the control system is used for obtaining the required aerodynamic flow parameter of the aircraft yawing motion, sending the thrust instruction for controlling the thrust size of the left wing jet propeller and the thrust instruction for controlling the thrust size of the right wing jet propeller to the thrust control device based on the aerodynamic flow parameter, and using the thrust difference between the left and right jet propellers to form a yawing control moment to control the yawing motion of the aircraft, so that the yawing axis control stability and dynamic control of the aircraft are enhanced through the flight control system controlling the yawing moment.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of aircraft overall design, propulsion system, aerodynamic layout design and flight control, and particularly relates to a jet propulsion system and a method for enhancing the dynamic control ability of a flying wing aircraft. BACKGROUND

[0002] The jet propulsion system can be an electric turbojet engine, or a device that sprays a high-speed induced flow on the pipe wall and uses the low-pressure area formed by the jet flow in the pipe cavity to cause the surrounding gas to increase the flow and form thrust.

[0003] The aerodynamic layout of an aircraft cancels the vertical tail, resulting in static instability of the aircraft yaw axis and a serious lack of yaw control moment sources. The existing aerodynamic control surfaces, such as the split resistance rudder, the all-moving wing tip, and the spoiler, cannot meet the aircraft's maneuvering requirements during high maneuvering. The large sweepback layout of the aircraft results in a short force arm of the yaw aerodynamic control surface placed on the outside of the wing, and the yaw moment increment is insufficient. This aerodynamic layout cancels the horizontal tail control surface, resulting in a serious nonlinearity of the aircraft body's pitch moment upward when the angle of attack increases by more than 10°, and the pitch axis instability increases sharply, which seriously consumes the aircraft's pitch axis control resources, and even leads to loss of control of the aircraft.

[0004] Based on the above background needs, the present patent uses a jet propulsion system integrated on the outside of the wing to solve the above needs SUMMARY

[0005] To solve the above problems, the application provides a jet propulsion system, comprising:

[0006] Jet propellers are symmetrically installed on the left and right wings of the aircraft, respectively.

[0007] A thrust control device is used to receive thrust instructions from a control system and control the thrust size of the jet propeller.

[0008] A control system is used to obtain the required aerodynamic flow parameters of the aircraft yaw motion, and based on the aerodynamic flow parameters, the control system sends the thrust control device a thrust instruction for controlling the thrust size of the left wing jet propeller and a thrust instruction for controlling the thrust size of the right wing jet propeller.

[0009] Preferably, the aerodynamic flow parameters include: aircraft lift, drag side force, roll moment, yaw moment, and pitch moment aerodynamic increment.

[0010] Preferably, the inlet of the jet propeller is further provided with a position-adjustable baffle, and the displacement of the baffle is controlled by the control system to reduce the thrust of the jet propeller and increase the resistance.

[0011] Preferably, the jet propulsion system further comprises a feedback module for feeding back jet propulsion state information to the control system.

[0012] A method for enhancing the maneuverability of a flying wing aircraft, using the jet propulsion system,

[0013] Obtaining state parameters of the aircraft yawing motion;

[0014] Obtaining aerodynamic flow influence parameters required for controlling the pitch axis stability based on the state parameters of the aircraft yawing motion;

[0015] Obtaining the thrust size of the left wing jet propulsion and the thrust size of the right wing jet propulsion based on the aerodynamic flow influence parameters;

[0016] Based on the thrust size, using the control system to send thrust instructions to the thrust control device respectively;

[0017] Based on the thrust instructions, using the thrust control device to control the size of the jet propulsion inlet valve based on the flight height and Mach number of the aircraft respectively.

[0018] Preferably, it comprises:

[0019] The thrust size is obtained based on mathematical model solving, and the method for establishing the mathematical model comprises:

[0020] Establishing an aircraft model with vertical tail through a simulation system;

[0021] Obtaining the aerodynamic flow influence parameters and the state parameters of the aircraft yawing motion when the aircraft model with vertical tail is flying through simulation experiments;

[0022] Establishing a mathematical model of the aerodynamic flow influence parameters and the state parameters of the aircraft yawing motion when the aircraft model with vertical tail is flying based on the aerodynamic flow influence parameters and the state parameters of the aircraft yawing motion when the aircraft model with vertical tail is flying;

[0023] Establishing an aircraft model with jet propulsion, changing the simulation experiments to obtain the thrust size of the jet propulsion and the difference between the jet propulsions, and obtaining the corresponding aerodynamic flow influence parameters when the aircraft model is flying;

[0024] Establishing a mathematical model of the aerodynamic flow influence parameters when the aircraft model is flying and the thrust size of the jet propulsion and the thrust difference between the jet propulsions

[0025] The application is arranged with one jet propeller on each outer section of the left and right wings of the aircraft, 1) to form a yaw control moment with the thrust difference of the left and right jet propellers (the vertical distance from the center of gravity of the aircraft to the thrust line of the jet propeller is the yaw arm), to control the yaw movement of the aircraft, and to realize the control stability and maneuvering control of the yaw axis of the aircraft through the flight control system; 2) to control the flow field on the upper surface of the wing by the jet output of the jet propeller, to suppress the occurrence of lateral flow along the spanwise direction of the wing at high angles of attack, to suppress the nonlinear unstable upward of the pitch moment and to improve the aerodynamic control effectiveness of the wing trailing edge rudder, to expand the maneuvering angle range; 3) to accelerate the airflow velocity on the upper surface of the wing by the jet output of the jet propeller, to increase the lift of the wing, and to improve the lift-drag ratio of the aircraft; 4) to improve the aerodynamic flow field of the trailing edge of the wing by the jet output of the jet propeller, to increase the aerodynamic control effectiveness of the rudder. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a preferred embodiment of the application, a flow chart of a method for enhancing the maneuvering capability of a flying wing aircraft. DETAILED DESCRIPTION

[0027] In order to make the technical solutions of the application and its advantages clearer, the technical solutions of the application will be further clearly and completely described below in combination with the drawings. It should be understood that the specific embodiments described herein are only part of the embodiments of the application, and are only used to explain the application, but not to limit the application. It should be noted that, for the purpose of description, only parts related to the application are shown in the drawings, and other related parts can be referred to the usual design. In the case of no conflict, the embodiments in the application and the technical features in the embodiments can be combined to obtain new embodiments.

[0028] In addition, unless otherwise defined, technical terms or scientific terms used in the description of the present application shall be understood as the common meaning understood by one of ordinary skill in the art to which the present application belongs. The words "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer" and the like used in the description of the present application only indicate relative directions or positional relationships, and do not imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and the relative positional relationship may change accordingly when the absolute position of the described object changes, therefore it cannot be understood as a limitation to the present application. The "first", "second", "third" and the like used in the description of the present application are only for the purpose of description, in order to distinguish different components, and cannot be understood as indicating or implying relative importance. The "one", "a" or "the" and the like used in the description of the present application should not be understood as an absolute limitation on the quantity, but should be understood as the presence of at least one. The "includes" or "contains" and the like used in the description of the present application means that the elements or objects appearing before the word are covered by the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0029] In addition, it should be noted that, unless otherwise specified and limited, the "installation", "connection", "connection" and the like used in the description of the present application should be understood broadly, for example, the connection can be fixed connection, or detachable connection, or integral connection; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements, and those skilled in the art can understand the specific meaning of the present application according to the specific circumstances.

[0030] A jet propulsion system, comprising jet propellers, respectively symmetrically installed on the left wing and the right wing of the aircraft;

[0031] A thrust control device for receiving thrust instructions issued by the control system and controlling the thrust size of the jet propeller;

[0032] A control system for obtaining the required aerodynamic process parameters of the aircraft yawing motion, and sending the thrust instructions for controlling the thrust size of the left wing jet propeller and the thrust instructions for controlling the thrust size of the right wing jet propeller to the thrust control device based on the state parameters, wherein the aerodynamic process parameters include: the aerodynamic increments of the lift, drag, side force, roll moment, yawing moment and pitching moment of the aircraft.

[0033] A feedback module for feeding back the working state information of the jet propeller to the control system

[0034] The intake of the jet propeller is further provided with a position-adjustable baffle, and the displacement of the baffle is controlled by a control system to reduce the thrust of the jet propeller and increase the resistance.

[0035] A method for enhancing the dynamic maneuverability of a flying wing aircraft, using the jet propulsion system,

[0036] Obtaining state parameters of the aircraft yawing motion;

[0037] Based on the state parameters, obtaining the aerodynamic flow influence parameters required for the control control pitch axis stability of the aircraft yawing motion;

[0038] Based on the aerodynamic flow influence parameters, obtaining the thrust size of the left wing jet propeller and the thrust size of the right wing jet propeller respectively;

[0039] Based on the thrust size, using the control system to send thrust instructions to the thrust control device respectively;

[0040] Based on the thrust instructions, using the thrust control device to control the size of the jet propeller intake valve based on the flight height and Mach number of the aircraft respectively;

[0041] Wherein, including:

[0042] The thrust size is obtained based on mathematical model solving, and the method for establishing the mathematical model comprises:

[0043] Establishing an aircraft model with a vertical tail through a simulation system;

[0044] Obtaining the aerodynamic flow influence parameters and the state parameters of the aircraft yawing motion when the aircraft model with a vertical tail is flying through simulation experiments;

[0045] Based on the aerodynamic flow influence parameters and the state parameters of the aircraft yawing motion when the aircraft model with a vertical tail is flying, a mathematical model of the aerodynamic flow influence parameters and the state parameters of the aircraft yawing motion when the aircraft model with a vertical tail is flying is established;

[0046] Establishing an aircraft model with a jet propeller, changing the simulation test to obtain the thrust size of the jet propeller and the difference between the jet propellers, and obtaining the corresponding aerodynamic flow influence parameters when the aircraft model is flying;

[0047] Establishing a mathematical model of the aerodynamic flow influence parameters when the aircraft model is flying and the thrust size of the jet propeller and the thrust difference between the jet propellers.

[0048] The actual design process of the aircraft of the present application comprises:

[0049] Step 1: design a jet propulsion engine according to the aerodynamic and propulsion system mechanism, so as to generate thrust meeting the target requirements, including designing the jet propulsion engine pipeline aerodynamic layout, jet port aerodynamic layout, jet port arrangement scheme in the jet propulsion engine pipeline, and evaluating thrust and jet flow requirements;

[0050] Step 2: determine a jet flow air supply scheme according to the jet flow requirements, including setting a separate air compressor and an engine compressor or an outer duct air supply scheme, and designing a jet valve control scheme for adjusting the jet flow and a jet propulsion engine control system;

[0051] Step 3: determine the installation position of the jet propulsion engine according to the aerodynamic control requirements, and iteratively determine the aerodynamic geometric characteristics of the jet propulsion engine pipeline and external contour with steps 1 and 2;

[0052] Step 4: establish a jet propulsion engine aerodynamic model (CFD calculation and wind tunnel test), establish an aircraft flight dynamics model integrated with the jet propulsion engine aerodynamic model, evaluate in detail the thrust and torque index requirements of the jet propulsion engine and the influence of the comprehensive aerodynamic characteristics on the flight control, and iteratively design with steps 1, 2 and 3;

[0053] Step 5: design a flight control system scheme based on the jet controller;

[0054] Step 6: carry out detailed maneuvering and stability evaluation and control law scheme design based on the aircraft flight dynamics model of step 4;

[0055] Step 7: carry out a semi-physical simulation test environment, integrate the jet propulsion engine system, the jet air supply system, the jet propulsion engine control system, the flight control system and the full aircraft aerodynamic model, and carry out simulation verification based on the above environment;

[0056] Step 8: carry out a scale-down flight test and a full-size aircraft verification flight test;

[0057] The present application arranges one jet propulsion engine on each outer section of the left and right wings of the aircraft, 1) uses the thrust difference between the left and right jet propulsion engines to form a yaw control moment (the vertical distance from the center of gravity of the aircraft to the thrust line of the jet propulsion engine is the yaw arm), controls the yaw movement of the aircraft, and realizes the control stability and maneuvering control of the yaw axis of the aircraft through the flight control system; 2) uses the jet output of the jet propulsion engine to control the flow field on the upper surface of the wing, suppresses the occurrence of the lateral flow along the wing span in the high angle of attack state, thereby suppressing the nonlinear unstable upward pitch of the pitch moment and improving the aerodynamic control efficiency of the wing trailing edge rudder, and expanding the maneuvering angle of attack range; 3) uses the jet output of the jet propulsion engine to accelerate the airflow velocity on the upper surface of the wing, increases the lift of the wing, and improves the lift-drag ratio of the aircraft; 4) uses the jet output of the jet propulsion engine to improve the aerodynamic flow field of the wing trailing edge, and increases the aerodynamic control efficiency of the rudder.

[0058] The above description is provided as an enabling teaching of the application and is not intended to limit its scope in any way. Any modification of the application in keeping with the spirit thereof that is made within the scope of the application as claimed should be clearly within the scope of the application.

Claims

1. A method for enhancing the dynamic control capability of a flying wing aircraft, based on a jet propulsion system, comprising: The jet propulsion units are symmetrically installed on the left and right wings of the aircraft. The thrust control device is used to receive thrust commands from the control system and control the thrust magnitude of the jet propulsion device. The control system is used to acquire the aerodynamic process parameters required for the aircraft's yaw motion, and based on the aerodynamic process parameters, send thrust commands to the thrust control device to control the thrust magnitude of the left wing jet thruster and the right wing jet thruster, respectively. The method is characterized by comprising: Obtain the state parameters of the aircraft's yaw motion; Based on the state parameters, obtain the aerodynamic process parameters required for the control to stabilize the pitch axis of the aircraft by controlling the yaw motion. The thrust magnitudes of the left wing jet propulsion unit and the right wing jet propulsion unit were obtained based on aerodynamic process influence parameters. Based on the thrust magnitude, the control system sends thrust commands to the thrust control device. Based on thrust commands, the thrust control device controls the size of the jet propulsion inlet valves based on the aircraft's flight altitude and Mach number. The magnitude of the thrust is obtained based on a mathematical model, and the method for establishing the mathematical model includes: An aircraft model with a vertical tail was created using a simulation system; The aerodynamic process parameters and yaw motion state parameters of the aircraft model with a vertical tail were obtained through simulation experiments. A mathematical model of the aerodynamic process influence parameters and yaw motion state parameters of an aircraft model with a vertical tail during flight is established. An aircraft model with jet thrusters was established. Simulation experiments were conducted to obtain the thrust magnitude of the jet thrusters and the difference between jet thrusters, and the corresponding aerodynamic flow parameters of the aircraft model during flight were obtained. A mathematical model is established to reflect the aerodynamic process influence parameters, the thrust magnitude of the jet propulsion system, and the thrust difference between the jet propulsion systems during the flight of the aircraft model.

2. The method for enhancing the dynamic control capability of a flying wing aircraft as described in claim 1, characterized in that, The aerodynamic process parameters include: aircraft lift, drag lateral force, roll moment, yaw moment, and pitch moment aerodynamic increments.

3. The method for enhancing the dynamic control capability of a flying wing aircraft as described in claim 1, characterized in that, The air inlet of the jet thruster is also equipped with an adjustable baffle. The displacement of the baffle is controlled by the control system to reduce the thrust of the jet thruster and increase the drag.

4. The method for enhancing the dynamic control capability of a flying wing aircraft as described in claim 1, characterized in that, The jet propulsion system also includes a feedback module, which is used to provide feedback on the operating status information of the jet propulsion unit to the control system.

Images