Non-piped propulsion system

Abstract

Apparatuses and systems are provided herein for non-pipeline propulsion systems. The system includes a low-drag aft fairing for high subsonic sustained flight. A plurality of vanes are secured to the aft fairing, wherein the fairing defines a flow path curve extending from an axial extent of the aft vane root to an aft end of the aft fairing. The flow path curve is described by an axial direction parallel to an axis of rotation and a radius from the axis of rotation. The flow path curve includes a first point and a second point forward of the first point, the first point having a first radius, wherein the radius reaches a maximum value aft of the aft vane root, the second point having a second radius, wherein the radius ceases to decrease. A ratio of the first radius to the second radius is greater than or equal to 1.081.

Description

[0001] This application is a divisional application of the invention patent application filed on October 14, 2022, with application number 202211261676.7 and invention title "Non-pipeline propulsion system". Technical Field

[0002] This technology largely involves non-pipeline propulsion systems. Background Technology

[0003] Typically, aircraft propulsion systems generate thrust by accelerating the air passing through the fan. Factors detrimental to thrust generation efficiency include energy losses as air enters and passes through the fan, velocity contributions that do not contribute to thrust (e.g., swirling and eddy currents in the air leaving the fan), frictional drag on the outer surfaces of the propulsion system, and shock wave-related drag (e.g., wave drag) on ​​the outer surfaces of the propulsion system. Therefore, for aircraft propulsion systems, the goal is to generate a given amount of thrust without providing excessive input power to the fan. Thus, minimizing inefficiencies in thrust generation is desirable. Attached Figure Description

[0004] This document discloses embodiments of systems and apparatus related to non-pipeline propulsion systems. This specification includes accompanying drawings, in which:

[0005] Figure 1 A front cross-sectional view of an exemplary non-pipeline propulsion system having a rotation axis, front and rear blade assemblies, front and rear housings, an engine inlet, and an engine outlet according to some embodiments is shown.

[0006] Figure 2 This is a schematic perspective view of an exemplary gas turbine engine attached to the wing of an aircraft according to some embodiments;

[0007] Figure 3 This is a cross-section of an exemplary non-pipeline propulsion system according to some embodiments, showing the curvature along the flow path curve;

[0008] Figure 4 The airflow through a blade assembly of a non-pipeline propulsion system is shown according to some embodiments;

[0009] Figure 5 This illustrates the effect of air movement on a nonlinear solid surface;

[0010] Figure 6 A schematic diagram of three surface locations defining an exemplary flow path profile for a rear housing according to some embodiments is shown;

[0011] Figure 7 An example of a flow path curve for a rear housing according to some embodiments is shown;

[0012] Figure 8 Illustrations are shown according to some embodiments Figure 7 An exemplary plot of the same three flow path curves with respect to their first derivatives with respect to axial distance;

[0013] Figure 9 By illustrating relative to some embodiments Figure 7 The curvature is illustrated by the second derivative of the axial distance between the three curves in the figure;

[0014] Figure 10 Illustrations are shown according to some embodiments Figure 1 The same front cross-sectional view of the non-pipeline propulsion system, but the component numbering specifically refers to the front housing or rotator section;

[0015] Figure 11 Figure 200 is a depiction of the shape of the front housing of a non-pipeline propulsion system according to some embodiments;

[0016] Figure 12 Figure 1200 is a depiction of the shape boundaries of the front housing of a non-pipeline propulsion system according to some embodiments; and

[0017] Figure 13 This is a flowchart of a method for operating a non-pipeline propulsion system according to some embodiments.

[0018] The elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions and / or relative positioning of some elements in the figures may be exaggerated relative to other elements to aid in understanding the various embodiments of this disclosure. Furthermore, common but easily understood elements that are useful or necessary in commercially viable embodiments are generally not depicted to facilitate a less obstructive view of these different embodiments of this disclosure. The front cross-sectional view of the non-pipeline propulsion system in the figures depicts the external flow path curve formed by the intersection of the outer surface of the housing and the plane including the axis of rotation. Such a cross-sectional view also indicates structures, such as blades, that aid in understanding the embodiments of this disclosure. Limiting the cross-sectional view to one side of the axis of rotation does not imply that the system is axisymmetric about the axis of rotation. The cross-sectional view is used to illustrate certain characteristics, such as the shape of the housing associated with the blade assembly. Furthermore, the figures omit certain details of the system that are not required to fully understand certain aspects of the system. Certain actions and / or steps may be described or depicted in a specific sequence of occurrence, and those skilled in the art will understand that such specificity regarding sequence is not actually necessary. Unless otherwise defined herein, the terms and expressions used herein have the general technical meanings that a person skilled in the art would assign to them based on the terms and expressions as set forth above. Detailed Implementation

[0019] The aspects and advantages of this disclosure will be set forth in part in the description which follows, or may be apparent from the description, or may be learned by practice of this disclosure.

[0020] Reference will now be made in detail to the present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numbers and letters to refer to features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to refer to similar or analogous portions of the invention.

[0021] The term “exemplary” is used herein to mean “used as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as superior to or better than other implementations.

[0022] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the individual components.

[0023] The terms "front" and "rear" refer to relative positions within a gas turbine engine or carrier, and specifically to the normal operating posture of the gas turbine engine or carrier. For example, in the case of a gas turbine engine, "front" refers to the position closer to the engine inlet, while "rear" refers to the position closer to the engine outlet or exhaust port.

[0024] The terms "upstream" and "downstream" refer to the relative directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction from which the fluid flows.

[0025] Unless otherwise stated herein, the terms “connection,” “fixed,” “attached to,” etc., refer to both direct connection, fixation, or attachment, and indirect connection, fixation, or attachment via one or more intermediate components or features.

[0026] The term "propulsion system" generally refers to a system that generates thrust, which is produced by a thruster, and the thruster uses an electric motor, a thermal engine (such as a turbine), or a combination of an electric motor and a turbine to provide said thrust.

[0027] The term "shell" refers to the outer shell that surrounds the propulsion system and provides an aerodynamic exterior. The shell can consist of or include a hub, a rotor, and a nacelle. Furthermore, the shell can rotate about a rotational or stationary axis, or be axially segmented such that one part rotates while another remains stationary.

[0028] Unless the context clearly indicates otherwise, the singular forms “a,” “a,” and “the” include plural references.

[0029] For a flow path curve corresponding to the outer surface of the housing, the axial direction "z" is parallel to the axis of rotation, and the radius "r" is the distance from the axis of rotation. The zr plane is located by the angular coordinate theta (i.e., using a cylindrical coordinate system, where the coordinate theta precisely positions the orientation of the zr plane in 3D space). Because the outer surface of the housing may not be axisymmetric about the axis of rotation, the shape of the flow path curve may depend on the zr plane used to define it. In the specification and claims, in addition to specifying that it includes the axis of rotation, the zr plane used to define the flow path curve also includes a point on the blade root within the housing or the blade assembly associated with the housing described by the curve, closest to the housing described by the curve. Furthermore, for any axial position z of the curve rotating about the axis of rotation of the housing, the radius r is not the radius on the flow path curve at a specified zr position relative to the axis of rotation, but rather the "effective" radius of the housing cross-sectional area perpendicular to the axis of rotation at that axial z position. Thus, for the axial position of the housing rotation, the radius r is the radius of a circle having the same housing cross-sectional area in a plane section perpendicular to the axis of rotation.

[0030] The term "bump" refers to a location on the flow path curve where the radius reaches its maximum along the curve away from the nearest / associated blade assembly (i.e., in front of the front blade assembly for the front housing and behind the rear blade assembly for the rear housing).

[0031] The term "local minimum" refers to the first position on a segment of the flow path curve, extending axially from the bulge towards and through the associated blade root, where the radius stops decreasing. If the radius monotonically decreases axially from the bulge through the associated blade root, the local minimum is located on the segment of the flow path curve furthest from the bulge. Therefore, the local minimum is the minimum radius position closest to the maximum radius position, which is also within the axial range of the blade root or between the blade root and the maximum radius position. It should be understood that when determining the local minimum, any gaps or steps in the flow path curve caused by connections, fits, or relative motion between components of the housing are ignored.

[0032] As used throughout the specification and claims, approximate language is applied to modify any quantitative expression that may allow for variation without altering its underlying function. Therefore, values ​​modified by terms such as “about,” “approximately,” and “substantially” are not limited to specified exact values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to a margin of 1%, 2%, 4%, 10%, 15%, or 20%.

[0033] Throughout this specification and claims, scope limitations are combined and interchanged, and unless the context or language otherwise indicates otherwise, such scopes are identified and include all subscopes contained herein. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0034] The technology described herein relates to non-pipeline propulsion systems, and in particular to the shape of the outer surface of one or more housings surrounding the propulsion system, for which the housings may include a rotor, a hub, and / or a nacelle.

[0035] Turbofan engines operate by having a central gas turbine core drive a bypass fan located radially between the fan duct and the engine core. In contrast, ductless propulsion systems operate by placing the bypass fan outside the engine nacelle. This allows for the use of larger fan blades capable of handling a greater volume of air than in a turbofan engine, resulting in improved propulsion efficiency compared to conventional engine designs.

[0036] Non-ducted propulsion systems can take the form of propeller systems used in a wide range of aircraft, such as radio-controlled model airplanes, drones, piston-engine propeller aircraft, turboprop regional aircraft, and large turboprop military transport aircraft. Another type of non-ducted propulsion system (sometimes called an "open rotor") consists of two blade assemblies, one in a forward position and one in a rearward position, with at least one of them rotating about an axis to transmit power to the propulsive flow that generates thrust. Such two-bladed assembly systems offer some advantages but also present some challenges and are far less common than single-bladed systems. As used herein, the term "propeller" can refer to a single blade assembly of a non-ducted propulsion system or the forward blade assembly of a non-ducted propulsion system consisting of two blade assemblies. The term "fan" can refer to either a propeller or a two-bladed assembly of a non-ducted propulsion system.

[0037] According to this disclosure, a non-ducted propulsion system is capable of achieving high subsonic cruise speeds. Cruise is a phase of flight that occurs after the aircraft has climbed and before it begins to descend to a set altitude. Therefore, as used herein, cruise represents the continuous, high-speed, and stable flight conditions under which the aircraft is intended to operate. This description is intended to distinguish cruise from certain anomalous or transient conditions (such as dives) under which the aircraft can achieve high speeds, but which the aircraft is not intended to experience for most of its mission from takeoff to landing.

[0038] A non-ducted propulsion system capable of achieving maximum subsonic cruise flight can have two blade assemblies aerodynamically positioned relative to each other. As used herein, "aerodynamic relationship" means that they are positioned such that one is downstream of the other, so that at least a portion of the air acted upon by the leading blade assembly is subsequently acted upon by the trailing blade assembly. This allows the tangential velocity (also known as vortex) imparted to the air by the leading blade assembly to be neutralized, or at least partially canceled, by the variation in tangential velocity imparted by the trailing blade assembly. At least one of the blade assemblies is a rotating assembly carrying an array of airfoil blades rotating about an axis of rotation and located outside the engine nacelle. The other blade assembly can be another rotating blade assembly (rotor), or it can be a stationary blade assembly (stator). Without the trailing blade assembly to counteract the vortex of the leading blade assembly, the high power required per unit frontal or annular fan area for high-speed flight would generate excessive vortex in the air passing through the non-ducted propulsion system, resulting in inefficient thrust generation. For this reason, single-propeller propulsion systems (such as the propeller on a turboprop engine) typically power aircraft with cruise Mach numbers not exceeding 0.72.

[0039] If a non-pipeline propulsion system comprises two blade assemblies, both of which are rotors, then the blades of the front and rear blade assemblies are arranged to rotate about a common axis in opposite directions and are axially spaced along that axis. For example, the corresponding blades of the front and rear rotor assemblies may be coaxially mounted and spaced apart, with the blades of the front rotor assembly configured to rotate clockwise about the axis and the blades of the rear rotor assembly configured to rotate counterclockwise about the axis (and vice versa).

[0040] If one of the two blade assemblies is the stator, that blade assembly does not rotate about its axis and is aerodynamically positioned upstream or downstream of the rotating blade assembly, namely the front blade assembly or the rear blade assembly. If aerodynamically positioned upstream of the rotating blade assembly, the stationary blade assembly imparts a tangential velocity to the air in a direction opposite to the rotor's rotation direction, known as anti-swirl. Due to the rotation direction, the rear rotating blade assembly imparts a change in tangential velocity to the air to reduce the magnitude of the tangential velocity passing through it. If aerodynamically positioned downstream of the rotating blade assembly, the stationary blade assembly imparts a change in tangential velocity in a direction opposite to the rotor's, known as deswirl. By deswirling the air it receives from the rotating blade assembly, the rear blade assembly reduces the magnitude of the tangential velocity passing through it. The blades in the stator are commonly referred to as "rotor blades." However, the general terms "blade" and "blade assembly" used herein refer to both rotating and stationary blade assemblies.

[0041] For stationary blade assemblies, the aircraft structure can be mixed, integrated, or merged with the blade assembly. For example, the pylon for mounting the engine to the aircraft can occupy some of the same axial range along the rotation axis of the rotating blade assembly as at least some of the blades in the stationary blade assembly. Furthermore, portions of the aircraft structure can be designed for the purpose of counter-swirling flow in the forward blade assembly or deswirl flow in the aft blade assembly. Therefore, the aircraft structure can add to or even replace some blades in the stationary blade assembly.

[0042] As used herein, the locations or coordinates indicated by distances parallel to and perpendicular to the axis of rotation define the external flow path surfaces of the indicated structure. These external flow path surfaces work in conjunction with the blade assembly to influence the flow of the working fluid (typically air) through the fan. The external flow path surfaces, formed by one or more housings, are separated from the fan-accelerated airflow and the internal mechanisms, mechanics, or equipment associated with the propulsion system. As the flight Mach number and the air acceleration through the fan increase, the shape of these external flow path surfaces becomes increasingly important for avoiding high-pressure losses or drag. Furthermore, these external flow path surfaces may protrude axially away from the vicinity of the blade assembly (i.e., increase in size) to accommodate the aforementioned internal components.

[0043] For non-ducted propulsion systems, high-speed flight requires even higher speeds to pass through the fan and through the flow path surface formed by one or more casings. As used herein, a “fan flow” is a fluid flow accelerated by a fan to generate thrust. Such speeds can reach or exceed the speed of sound, or Mach 1. Under certain conditions, high-Mach flow can lead to a sharp increase in pressure loss and drag, thereby impairing the system’s thrust-generating performance or efficiency. This can result in poor fuel efficiency. Furthermore, it may be desirable to limit the fan diameter to avoid the disadvantages associated with weight, drag, and installation on the aircraft. However, compact fans result in higher thrust per unit frontal or annular area of ​​the fan, and therefore higher acceleration compared to a case where the fan diameter is not so limited. In addition, the axial length of the system, and thus the length of the flow path surface that defines the fan flow, affects drag and weight. At the same time, reducing the axial length can also impair the performance of non-ducted propulsion systems by resulting in a larger flow path surface curvature, leading to high Mach number regions. Therefore, it is desirable to provide a non-ducted propulsion system having an external flow path shape of the casing located upstream of the front blade assembly and within its axial range, enabling the aircraft to fly at high subsonic speeds with good efficiency and transonic flow within the fan. It is also desirable to provide a non-ducted propulsion system having an external flow path shape of the casing located downstream of the rear blade assembly and within its axial range, enabling the aircraft to fly at high subsonic speeds with low losses and low drag.

[0044] According to the present disclosure, a ducted propulsion system for a subsonic aircraft having a cruise Mach number M0 of 0.74 or greater (e.g., 0.74 < M0 < 0.86) or between a cruise Mach number of 0.78 and 0.84 has a rotational axis, a front blade assembly, a rear blade assembly, a front housing, and a rear housing. The front blade assembly and the rear blade assembly each include a plurality of blades, each blade having a root near the rotational axis and a tip away from the rotational axis. The flow path curve corresponds to the intersection line of the outer surface of the rear housing and the plane containing the rotational axis and the last point of the rear blade root. For the flow path curve, the axial direction z is parallel to the rotational axis and increases in the backward or downstream direction. For the flow path curve, the radial coordinate r is the distance from the rotational axis.

[0045] The flow path curve has a bulge and a local minimum. The bulge position at a radius of r b is found by traveling backward from the last point of the rear blade root to the position where the radius reaches its maximum value. The local minimum position at a radius of r h is found by traveling axially forward from the bulge to the position where the radius stops decreasing. The ratio r b / r h > 1.08. Further, the axial distance z b between the bulge and the local minimum can conform to a ratio z b / r h < 2.41. Further, the flow path curve can have a position at a radius of r m axially midway between the bulge and the local minimum such that (r m / r h - 1) / (r b / r h - 1)> 0.59. The above ratios can be adjusted according to a predetermined cruise Mach number M0, as shown in EQS. 1, 2, and 3 presented below in sequence:

[0046]

[0047]

[0048]

[0049] In the above equations, 0.74 < M0 < 0.86, and the constants A1, B1, and C1 range from 1.11 < A1 < 1.31, 1.23 < B1 < 1.63, and 0.59 < C1 < 0.79. The above relationships for the flow path curve corresponding to the rear blade root can apply to the flow path curves associated with multiple rear blade roots, or to the flow path curve associated with all rear blade roots.

[0050] According to the present disclosure, a ducted propulsion system for a subsonic aircraft with a cruise Mach number M0 of 0.74 or greater (e.g., 0.74 < M0 < 0.86) has a rotational axis, a front blade assembly, a rear blade assembly, a front housing, and a rear housing. The front blade assembly and the rear blade assembly each include a plurality of blades, each blade having a root near the rotational axis and a tip away from the rotational axis. The flow path curve corresponds to the intersection line of the outer surface of the front housing and a plane containing the rotational axis and the foremost point of the front blade root. For the flow path curve, the axial direction z is parallel to the rotational axis and increases in the forward or upstream direction. For the flow path curve, the radius r is the distance from the rotational axis. At the axial position where the front housing rotates about the rotational axis (e.g., the spinner), the radius r is the effective radius, i.e., the radius of a circle having the same cross-sectional area as the front housing perpendicular to the rotational axis.

[0051] The flow path curve has a bulge and a local minimum. The bulge with a radius of r1 is found by traveling forward from the foremost point of the front blade root to the position where the radius reaches its maximum value. The local minimum position with a radius of r2 is found by traveling backward from the bulge to the position within the axial range of the front blade root where the radius stops decreasing. The ratio r1 / r2 of the flow path curve > 1.029. In addition, the axial distance z1 between the bulge and the local minimum can conform to the ratio z1 / r2 < 1.522. In addition, the front housing can have a foremost point, where the axial distance z2 between the local minimum and the foremost end of the flow path curve can conform to the ratio z2 / r2 < 4.115. The above ratios can be adjusted to accommodate a predetermined cruise Mach number M0, as shown in EQS.4, 5, and 6 presented in sequence below:

[0052]

[0053]

[0054]

[0055] where 0.74 < M0 < 0.86, 1.04 < A2 < 1.14, 0.78 < B2 < 1.18 and 2.19 < C2 < 3.19.

[0056] Also in accordance with the present disclosure, a ducted propulsion system for a subsonic aircraft with a cruise Mach number M0 of 0.74 or greater (e.g., 0.74 < M0 < 0.86) includes a rotating element composed of a rotation axis, a front blade assembly, and a front housing. The front housing or spinner rotates about the rotation axis together with the front blade assembly. The front blade assembly includes a plurality of blades, each blade having a root near the rotation axis and a tip away from the rotation axis. The axial direction z of the spinner is parallel to the rotation axis and increases in the forward or upstream direction. The radius r of the spinner shape is the distance from the rotation axis. The radial coordinate r is the effective radius, i.e., the radius of a circle having the same cross-sectional area as the spinner perpendicular to the rotation axis. The spinner has a raised position with a radius of r1 at the maximum radius in front of the front blade assembly. Traveling axially backward from the raised portion, the spinner has a local minimum with a radius of r2, where the radius stops decreasing within the axial range of the front blade roots. The shape of the spinner is such that r1 / r2 > 1.066. Additionally, the axial distance z1 between the raised portion and the local minimum can satisfy the ratio z1 / r2 < 1.522. Further, the front housing can have a foremost point, where the axial distance z2 between the local minimum and the foremost end of the flow path curve can satisfy the ratio z2 / r2 < 4.115. The above ratios can be adjusted using EQS.4, 5, and 6 to suit a predetermined cruise Mach number M0, where 0.74 < M0 < 0.86, 1.09 < A2 < 1.14, 0.78 < B2 < 1.18, and 2.19 < C2 < 3.19.

[0057] These and other features, aspects, and advantages of the present disclosure and / or embodiments will be better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0058] Herein, and throughout the specification and claims, range limitations are combined and interchanged, and such ranges are identified and include all subranges subsumed therein unless the context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of each other.

[0059] In the following figures, like reference numerals are used to refer to like elements in the various embodiments depicted in the figures.

[0060] Figure 1 A front cross-sectional view of an exemplary ducted propulsion system 100 is shown. As Figure 1As shown, the non-pipeline propulsion system 100 takes the form of an open rotor propulsion system and has a rotating element 138, depicted as a propeller assembly. The rotating element 138 includes an array of blades 102 fixed to a front housing 106 and configured to rotate about a rotation axis 120 of the non-pipeline propulsion system 100. In an exemplary embodiment, the non-pipeline propulsion system 100 also includes a non-rotating stationary element 142, which includes an array of blades 104 (also referred to as wheel blades) arranged about the rotation axis 120. These blades may be arranged such that their distances from the propeller are not all equal. These blades are mounted to a stationary frame and do not rotate relative to the central axis 120. The non-rotating stationary element 142 includes a stationary rear housing 126. The front housing 106 and the rear housing 126 have three-dimensional outer surfaces. To explain the surface forming guidelines disclosed herein, parameters are defined along the flow path curve, corresponding to the intersection of the outer surface with a plane including the rotation axis. Therefore, the flow path curve 105 corresponds to the intersection line of the front housing 106 and the zr plane including the rotation axis. Similarly, the flow path curve 125 corresponds to the intersection line of the rear housing 126 and the zr plane including the axis of rotation. For reference purposes, Figure 1 It also depicts the forward direction, indicated by arrow 118.

[0061] like Figure 1 As shown, the exemplary non-pipeline propulsion system 100 also includes a drive mechanism 128 that provides torque and power to the rotating element 138 via a transmission (not shown). In various embodiments, the drive mechanism 128 (also referred to as an engine) may be a gas turbine engine, an electric motor, an internal combustion engine, or any other suitable torque and power source, and may be positioned close to the rotating element 138, or remotely positioned via a suitably constructed transmission. The transmission transfers power and torque from the drive mechanism 128 to the rotating element 138 and may include one or more shafts, gearboxes, or other mechanical or hydraulic drive systems. Figure 1 In this context, the drive mechanism 128 is schematically depicted as including a gas generator 130 and a power turbine 132. Examples of turbines comprising a gas generator (e.g., a compressor, combustor, and high-speed turbine) and a power turbine of a gas turbine engine are shown and described in US20210108597, which is hereby incorporated in its entirety for all purposes by reference. Similar descriptions are found in US10704410, US5190441, US9340277, and US10358926. Figure 1 The alternative constructions shown are hereby incorporated by reference in their entirety for all purposes.

[0062] When the rotating element 138 rotates about the rotation axis 120 in a given direction, the size, shape, and configuration of the airfoil blade 102 of the rotating element 138 are designed to... Figure 1 A working fluid (e.g., air) moves in the direction 144 to generate thrust. In doing so, blades 102 impart a degree of swirling to the fluid as it moves in direction 144. The size, shape, and configuration of the blades 104 of the stationary element are designed to reduce the magnitude of the fluid swirling, thereby increasing the kinetic energy that generates thrust for a given shaft power input of the rotating element. Each rotating blade 102 has a blade root 122 and a blade tip 124. Each stationary blade 104 has a blade root 136 and a blade tip 134. For both rotating blades 102 and stationary blades 104, the span is defined as the distance between the root and the tip. The stationary blade 104 may have a shorter span than the rotating blade 102 (e.g., 50% of the span of blade 102), or may have a longer span than or the same span as blade 102, depending on requirements. Figure 1 In this design, stationary blades 104 are shown attached to housing 126 at their respective blade roots 136. In some embodiments, some or all of the stationary blades 104 may be attached to or integrated with an aircraft structure (e.g., wing, pylon, or fuselage). The number of blades 104 of the stationary element may be less than, greater than, or equal to the number of blades 102 of the rotating element, and is typically greater than two or four. In some embodiments, the ratio of the number of rotating blades 102 to the number of stationary blades 104 is between 2:5 and 2:1. In some embodiments, the difference between the number of rotating blades 102 and the number of stationary blades 104 is between 2 and -2.

[0063] The blade 104 of the stationary element 142 can be aerodynamically positioned upstream of the rotating blade 102 to act as a counter-rotating impeller, i.e., imparting a tangential velocity opposite to the rotational direction of the rotating element 138. Or, as Figure 1 As shown, the stationary blade 104 can be aerodynamically positioned upstream of the rotating blade 102 to act as a deswirl vane, i.e., to impart a tangential velocity change opposite to that of the rotating element 138. Any swirl remaining in the airflow downstream of the non-ducted propulsion system 100 is equivalent to a thrust loss that generates kinetic energy.

[0064] It may be desirable for any one or both of the multiple sets of rotating blades 102 and multiple sets of stationary blades 104 to incorporate a pitch-changing mechanism, allowing the blades to rotate independently or in combination with each other relative to the pitch rotation axis. This pitch variation can be used to alter thrust and / or swirling effects under various operating conditions, including providing thrust reversal characteristics that may be useful under certain operating conditions, such as during aircraft landing.

[0065] Inlet 127 is axially located between blades 104 and 102. Alternatively, inlet 127 may be located elsewhere, such as in front of blade 102. The ratio of the mass of air accelerated by rotating blade 102 and bypassing inlet 127 to the mass of air accelerated by rotating blades and entering the engine core (not shown) via inlet 127 is called the bypass ratio. In some embodiments, the swept area of ​​the blades (calculated as π x [(blade tip radius)]) 2 –(Radius of leaf root) 2 The ratio of the cross-sectional area of ​​the inlet to the cross-sectional area of ​​the inlet (measured in the Zr plane) is greater than 20:1 or greater than 30:1, but less than 80:1.

[0066] It is worth noting that, Figure 1 The exemplary non-pipeline propulsion system 100 shown is merely an example. In other exemplary embodiments, it may have other suitable configurations. For example, instead of a front rotating blade assembly and a rear stationary blade assembly as shown, the two blade assemblies may rotate in opposite directions relative to each other. As another example, the front blade assembly may be stationary, and the rear blade assembly may rotate. As yet another example, the non-pipeline propulsion system may consist only of a rotating blade assembly (i.e., a propeller).

[0067] Figure 2 This is a perspective view of an exemplary gas turbine engine attached to the wing of an aircraft in accordance with certain aspects of this disclosure. Figure 2 A non-ducted propulsion system 100 is described, mounted to wing 218 via pylon 220 for easy installation into a frame structure or a housing within the frame structure. Furthermore, the spacing between each blade and / or at the same axial z-position may not all be equal. These are examples of how housing 126 may not be axisymmetric.

[0068] The non-pipeline propulsion system 100 includes a turbine substantially contained within a front housing or rotator 106 and a rear housing 126. In some configurations, both the front housing 106 and the rear housing 126 include rotating hubs associated with rotating blades 102 and 104, respectively. In other configurations, one of the front housing 106 and the rear housing 126 is fully rotatable or includes rotating structures (e.g., a rotating hub), while the other is a stationary housing associated with corresponding rotating and stationary blades. In some embodiments, the front housing 106 may be considered as a rotator, and the rear housing 126 may be considered as a nacelle. The rear housing 126 may contain the turbine's compressor, combustor, and turbine, followed by an engine outlet 121.

[0069] exist Figure 2In the illustrated, non-limiting example, the non-ducted propulsion system 100 includes a rotating assembly (or rotor) comprising an airfoil-shaped assembly of a front housing 106 and blades 102 (also referred to as a fan, rotor, or propeller) associated with the front housing 106. In this example, the front housing 106 is a rotator that rotates about a rotation axis 120. In other configurations, the front housing may not rotate, as the system consists of a stationary front blade assembly and a rotating rear blade assembly. The non-ducted propulsion system 100 also includes a stationary assembly comprising an engine inlet 127 and an airfoil-shaped stationary assembly of blades 104 associated with the rear housing 126. In this configuration, the housing 126 and blades 104 do not rotate about axis 120, although the blades may be individually articulated to modify, for example, the pitch angle, tilt angle, or sweep angle via mechanisms contained within the housing 126. At least one function of the stationary blade 104 assembly is to remove swirl from the airflow exiting the rotor.

[0070] The rear housing 126 extends axially from the engine inlet 127 to the engine outlet 121. The rear housing 126 contains internal machinery that generates torque for the blade 102 assembly and defines surfaces shaped to provide aerodynamic efficiency (drag reduction) for air flowing through the blades 102 and 104 and continuing downwards. The flow exiting the engine outlet 121 generates some thrust, propelling and / or propulsing the aircraft forward. A significant portion of the thrust generated by the engine of the non-ducted propulsion system 100 comes from accelerated air passing through the housing 126, or from air passing through the blades 104 and bypassing the inlet 127. In some embodiments, the engine may also include a third flow (the first and second flows are bypass and turbine core airflows defined by the compressor, combustor, and turbine).

[0071] To simplify Figure 2 As described in the illustration, the front housing 106 is shown as a continuous rotator. However, each housing may consist of separate sections with various mechanical components to allow for variable pitch angles of the front blade assembly 102 and / or the rear blade assembly 104. The axial range of such a dedicated section of each housing may be substantially the same as the corresponding axial range of the blade assembly 102 and / or the blade assembly 104, or the axial range of the housing may be shorter or longer (within the axial range) than the span of the blades or the corresponding axial range of the blade assembly. Figure 2The dotted line in the diagram indicates the axis of rotation 120 of blade 102. Dashed curves 105 and 125 represent flow path curves corresponding to the intersection lines of housings 106 and 126 with the plane including the axis of rotation 120, respectively. In an exemplary example where the front housing 106 and the associated front blade 102 assembly rotate about the axis of rotation 120, the shape of the flow path curve can be defined by the effective radius and the axial distance parallel to the axis of rotation 120. However, in this example where the rear housing 126 and the associated rear blade 104 assembly do not rotate about the axis of rotation 120, the shape of the flow path curve with respect to radius and axial position depends on the orientation of the zr plane about the axis of rotation; that is, the curve may have different shapes for different positions of the plane intersecting the rear housing 126.

[0072] refer to Figure 1 and Figure 2 Because of the thickness of the blade 102 assembly and / or the stationary blade 104 assembly, flow restriction, known as choking, may occur in the airflow through the blade 102 and / or blade 104 ducts. Therefore, the airflow is accelerated not only by the generated thrust but also by the choking, requiring further acceleration. In high subsonic cruise, for example at flight Mach number (M0) greater than approximately 0.74, the combined effects of the generated thrust and choking can cause the axial component of the airflow velocity through the duct to approach the speed of sound (i.e., Mach number 1), a phenomenon known as choking, which can lead to high-pressure losses within the blade 102 or blade 104 ducts. Higher blade 102 or blade 104 counts (e.g., 8 to 18) can make choking a major problem because increasing the count increases the overall blockage of the blade material for the airflow acceleration through the blade 102 assembly.

[0073] A strategy known as area ruling can reduce the Mach number in the channels within blade 102 or blade 104. To visualize area ruling, Figure 3 A cross-sectional view of a non-pipeline propulsion system 100 is shown. Flow path curve 125 corresponds to... Figure 1 and Figure 2The intersection line of the outer surface of the housing 126 with a sectional plane that includes the axis of rotation 120 and the last point of the trailing vane root 136 of the vane 104 in the trailing vane assembly. Thus, the points on the outer surface of the housing 126 are determined by selecting the vane root 136 and an upstream or downstream distance parallel to the axis of rotation 120 starting from the last point of the vane root 136. By forming the trailing housing surface recess 404, the Mach number within the passage of the vane 104 can be reduced. The trailing housing recess region 404 corresponds to a valley and is located at a local minimum radius of the surface of the housing. Referring to the corresponding airflow through the vane 104 and past the housing (i.e., the flow path curve 125), it can be seen that due to the concave shape of the housing at the location of the vane 104, the velocity is appropriately reduced. To achieve this recess region 404 that produces the desired result (reducing the Mach number at the vane 104 to avoid choking), the radial distance of the curve 125 from the axis of rotation 120 away from the vane 104 must increase, resulting in a downstream convex curvature 406 and possibly an upstream convex curvature 402. Thus, the housing 126 not only needs to bulge outward to accommodate the internal components of the propulsion system but also needs to bulge outward to avoid choking in the passage between the vanes 104.

[0074] On the surface of the housing upstream of the vane 104, a convex portion 402 can also be formed on the housing. Thus, the housing 126 can bulge outward to accommodate the internal components of the ducted propulsion system and bulge upstream to, for example, accommodate components or an inlet 127. It may also be desirable to minimize the axial length of the ducted propulsion system. The goal of avoiding choking while restricting the axial length may result in an increase in the surface curvature of the housing 126, causing local acceleration of the air along the flow path curve 125 (especially at the convex portion). As described below, in high-subsonic flight, there may be challenges with the curvature near the convex portion of the surface of the flow path curve 125.

[0075] Figure 4 Shows the airflow through Figure 1 the fan of the ducted propulsion system 100. The air has a velocity V0 (e.g., corresponding to 0.74 < M0 < 0.86) relative to the airspeed far upstream 502 of the ducted propulsion system 100 and the ducted propulsion system 100, which is the flight speed of the aircraft. Closer to the fan, the effect of the fan is to cause a higher air velocity as the air enters the fan. As the air passes through the fan, the fan powers the airflow through it to accelerate (i.e., further increase the velocity) the air passing through the remainder of the propulsion system. In the region far downstream 506 in the axial direction, the airflow reaches the exhaust velocity V e .

[0076] The airflow through the blade 104 assembly, from far upstream to far downstream, can be considered as an air duct (or fan duct) 508. The radial and axial extent of the fan duct 508 (slipstream airflow) is indicated by a hash region. The outer boundary 510 of the fan duct 508 intersects the outermost radial segment (or tip) 124 of the blade 102 assembly. The inner boundary 514 of the fan duct 508 intersects the blade 104 assembly near the flow path curve 125 and follows the shape of the flow path curve 125 immediately downstream of the blade 104 assembly. Because in this exemplary example, the engine inlet 127 draws in air from the innermost radial region between blades 102 and 104, the fan duct 508 does not include the portion of air that enters the engine inlet 127 through the blade 102 and exits through the engine outlet 121. The average axial velocity of the air at any axial location within the fan duct 508 can be visualized by the annular cross-sectional region 516 of the fan duct 508 at that location. For a selected location along the fan duct 508, examples of the annular cross-sectional region 516 of the fan duct 508 are far upstream 502, nacelle protrusion 504, and far downstream 506.

[0077] Since the mass flow rate of air is the same throughout the fan duct 508 and in any annular region downstream of inlet 127, and the air density is approximately constant throughout the fan duct 508, the average axial velocity of the air is approximately inversely proportional to the annular region 516. Therefore, at far upstream 502, the velocity entering the fan duct 508 has not yet increased due to the fan, and the annular region 516 is at its maximum. At far downstream 506, the fan duct 508 includes energized air with a higher velocity relative to the air velocity in far upstream 502, and therefore the annular region 516 is smaller than at 502. The smallest annular region relative to the annular region along the fan duct 508 appears on the housing 126 near the protrusion 504. At the nacelle protrusion 504, the air has been energized by the blade 104 assembly, the radial distance from the axis of rotation is the maximum radius, and the annular region 516 is the smallest relative to the other annular regions mentioned in the flow path curve 125. Therefore, the average axial velocity of the airflow on the housing 126 (the surface defining the flow path curve 125) is high, and this is attributed to the protrusions in the flow path curve 125.

[0078] Figure 5 This further explains the problem caused by the high average axial velocity of the airflow in the cabin. Figure 5 The effects of frictionless air flow from left to right on a wavy solid surface 604 are depicted. Streamlines 602 indicate the paths of fluid particles originating at different distances from the surface 604. Concave surfaces 606, or valleys, increase static pressure and decrease air velocity. Conversely, convex surfaces 608, or peaks, decrease static pressure and increase air velocity. Therefore, for Figure 1The flow on the housing 126, the change in static pressure, and the accompanying relative change in air velocity are largely controlled by the curvature associated with the housing 126.

[0079] The curvature of a surface can be represented by a corresponding radius of curvature. For example, at any point along the surface 604, a radius of curvature r c and a center of curvature 610 can be defined. For illustration, Figure 5 two radii of curvature 612, 614 and their corresponding centers (shown as “+”) 610 are shown, which correspond to two surface positions. At a distance to the left of the peak of the convex surface 608, the curvature is low, corresponding to a larger r c 614. Closer to the peak of the convex surface 608, the curvature is high, corresponding to a smaller r c 612. There are also low and high curvatures at positions within the concave surface 606. However, for points within the concave surface 606, the center of curvature is located above the curve 604, and the radius of curvature points towards the surface 604.

[0080] As described above, the air flow on the housing 126 can have an average velocity higher than the average velocity V of the fan flow downstream of the engine e This effect can pose problems for high-subsonic flight. In particular, when the air velocity on the flow path surface 125 approaches the speed of sound or Mach number = 1.0, the drag begins to increase sharply. Generally, the increase in frictional drag is approximately proportional to the square of the air velocity. However, as the Mach number increases, the contribution of wave drag to the increase in drag becomes greater. Wave drag is the drag generated by shock waves that form when the air flow near the housing surface 126 becomes supersonic (e.g., Mach number > 1.0).

[0081] The above explanations illustrate three factors that lead to high drag. The first factor is the high cruise flight Mach number M0, such as 0.74 < M0 < 0.86. The second factor is the high dimensionless cruise fan net thrust based on the fan annulus area and the flight speed. The same acceleration of the air flow by the fan that generates thrust also increases the drag on the housing 126 (e.g., the nacelle). Representing the thrust dimensionless in a way that takes into account the flight speed, environmental conditions, and the fan annulus area, the thrust parameter where F net is the cruise fan net thrust, ρ0 is the ambient air density, V0 is the cruise flight speed, and A an is the cross-sectional area of the fan flow tube at the fan inlet. The fan annulus area A is calculated using the maximum radius as the tip radius of the leading rotor blade and the minimum radius as the minimum radius of the fan flow tube entering the fan anThe third factor is that the maximum radius of the housing 126 is relatively large compared to the local minimum radius associated with the rear blade root 136, while the axial length between the local minimum radius and the maximum radius of the housing 126 and the ratio of the local minimum radius associated with the rear blade root 136 are relatively small.

[0082] The solution to the wave drag problem during high-subsonic flight (e.g., 0.74 < M0 < 0.86) is based on an unconventional surface curvature strategy to design the shape of the flow path curve 125 on the housing 126. Figure 6 A schematic diagram shows three surface positions 702, 704, and 706 on the flow path curve 125. For Figure 3 and Figure 4 , the flow path curve 125 corresponds to Figure 1 and Figure 2 the intersection line of the outer surface of the housing 126 shown in and the plane including the rotational axis 120 and the last point of the rear blade root 136 in the rear blade assembly. Thus, the curve 125 corresponds to traveling axially forward and backward along the surface of the housing 126 from the last point on the rear blade root 136. If the rear blade used to define the flow path curve 125 has a variable orientation (e.g., actuated by a pitch change mechanism), the most relevant rear blade orientation for positioning the flow path curve is when the last point of the rear blade root 136 is at the last position. If the last point of the rear blade root 136 is not attached to the housing 126, for example, there is a gap between the rear blade root 137 and the housing 126 to allow pitch variation, or the rear blade 104 is attached to the frame and suspended on the housing 126, then the curve 125 passes through the nearest point on the surface of the housing 126 to the last point of the rear blade root 136. Each surface position along the flow path curve 125 can be defined based on the (z,r) coordinate system 708, where the z-axis is the rotational axis 120 and r is the distance from the rotational axis 120.

[0083] The flow path curve 125 has a raised or maximum radius position 704 corresponding to (z b ,r b ) of the (z,r) coordinate system 708, and has a maximum radius r b . The flow path curve 125 has a local minimum position 702 corresponding to (0,r h ) of the (z,r) coordinate system 708 in front of the raised position at 704, and has a radius r h . The surface positions at (0,r h ) and (z b ,r b ) determine the axial and radial ranges of the segment of the flow path curve 125, where the shape is designed as described herein to solve the high wave drag problem of high-subsonic flight.

[0084] Flow path curve 125 has a (z,r) coordinate system 708 corresponding to (z) b / 2,r m The third position 706 of the curve 125 is located at the midway point between the first surface position 702 and the second surface position 704. For the fixed endpoints 702 and 704 of the segment of curve 125, specifying the position of 706 has a significant impact on the curvature distribution. Radius r h 113, r m 117, r b 111 and axial distance z b 115 is also like Figure 1 As shown.

[0085] For high subsonic cruise, achieving low drag without unnecessarily increasing the length of housing 126 at high subsonic cruise Mach numbers (i.e., M0 > 0.74) depends on the proper positioning of points / endpoints / locations 702, 704, and 706. For example, for sufficient bulges to suppress the Mach number within the rear blade assembly, a finite length to avoid excessive frictional drag and weight, and a finite convex curvature close to the bulge, it might be desirable to achieve a certain drag coefficient. b / r h >1.081, z b / r h <2.103 and (r m / r h -1) / (r b / r h -1)>0.59. By increasing the radius slightly more and the axial distance slightly less, r becomes... b / r h >1.118, z b / r h <1.974 and (r m / r h -1) / (r b / r h -1)>0.64 yields better results. Furthermore, applying an upper bound to the convexity makes r... b / r h A value of <1.424 may be beneficial.

[0086] Furthermore, the above ratios can be customized to accommodate a predetermined cruise flight Mach number M0, with constants A1, B1, and C1, as shown in EQs.1, 2, and 3.

[0087]

[0088]

[0089]

[0090] Among them, M0 > 0.74, A1 > 1.11, B1 < 1.63 and C1 > 0.59. Additional restrictions on each parameter may result in a more optimized structure, such as 0.74 < M0 < 0.86, 1.11 < A1 < 1.31, 1.23 < B1 < 1.63 and 0.59 < C1 < 0.79. Examples of further constraints on the constants used to construct the rear housing 126 include 1.16 < A1 < 1.31, 1.23 < B1 < 1.53 and 0.64 < C1 < 0.79. As another example of constant constraints, 1.16 < A1 < 1.26, 1.33 < B1 < 1.53 and 0.64 < C1 < 0.74.

[0091] Table 1 provides examples of the ratio of the bump radius (r b )111 to the local minimum radius (r h )113, where 1.11 < A1 < 1.31 (bold) and 0.74 < M0 < 0.86.

[0092]

[0093] Table 1

[0094] Table 2 provides examples of the ratio of the axial distance 115 between the local minimum and the bump position to the local minimum radius (r h )113, where 1.23 < B1 < 1.63 (bold) and 0.74 < M0 < 0.86.

[0095]

[0096] Table 2

[0097] Table 3 provides examples of the ratio (r m / r h - 1) / (r b / r h - 1), where 0.59 < C1 < 0.79 (bold) and 0.74 < M0 < 0.86.

[0098]

[0099] Table 3

[0100] In addition to applying to the range of the cruise flight Mach number M0, the above constraints on the curve 125 may be particularly beneficial for the range of the dimensionless cruise fan net thrust parameter normalized by the ambient density, the square of the cruise flight speed, and the annular area of the fan flow tube at the fan inlet.

[0101] In the above thrust parameter, F netis the cruise fan net thrust, ρ0 is the ambient air density, V0 is the cruise flight speed, and A an is the annular cross-sectional area perpendicular to the axis of rotation of the fan flow tube entering the fan. For Figure 1 the exemplary example shown, the annular area will use r t 101, the radial distance from the axis of rotation 120 to the tip of the blade 102 in the front blade assembly, and the minimum radius of the fan flow tube at the same axial position are calculated. For Figure 1 the example where the engine inlet flow occupies a part of the annular area of the front blade assembly, methods for estimating the minimum radius of the fan flow tube using parameters such as fan thrust, engine inlet flow rate, and flight conditions will be used by those skilled in the art. The thrust parameter can be greater than or equal to 0.060 (e.g., greater than 0.080 or greater than 0.084).

[0102] The unconventional surface curvature strategy described above for solving the wave drag problem of sustained high subsonic flight (e.g., 0.74 < M0 < 0.86) is applicable to the ducted propulsion system described herein. In certain configurations, the unconventional surface curvature strategy can be applicable to a ducted propulsion system without an engine inlet (omitting inlet 127); for example, the rotor is not driven by a gas turbine engine but by another type of machine (e.g., an electric motor). Figure 7 depicts three exemplary flow path curves 125 that can be used to define the surface of the housing 126 shown in Figure 1 and Figure 2 Graph 800. The flow path curves 125 are close to the rear housing 126 and are between the surface positions at (0, r h ) and (z b , r b ) in the (z, r) coordinate system 708, as shown in Figure 6 .

[0103] To explain how the points 702, 704, and 706 in Figure 6 define the shape of the rear housing 126 to reduce drag during high-speed flight, in the graph 800 of Figure 7 , three exemplary flow path curves 125 between the point 702 and the point 704 are plotted, where z and r are through the local minimum radius r hDimensionless values ​​were applied. For ease of comparison, the three curves conform to EQS.1, 2, and 3, where M0 = 0.79, A1 = 1.21, and B1 = 1.43, differing only in parameter C1. Flow path curve 802 corresponds to C1 = 0.50 and is described by a cubic polynomial shape, denoted as "cubic". Flow path curve 802 gives a smooth curvature change relative to curves 804 and 806. Flow path curve 804 corresponds to C1 = 0.61 and is denoted as "ex1". Flow path curve 806 corresponds to C1 = 0.69 and is denoted as "ex2". For more than one-third of its length, flow path curve 804 (designated as "ex1") has a faster radius increase with axial distance than curve 802. Flow path curve 806 (designated as "ex2") also has a faster radius increase than curve 802, but compared to curves 802 or 804, the peak radius of the shell (with the maximum radius r) is smaller. b The radius changes little near the position of the flow path curve (125). Figure 8 It shows Figure 7 The curves in Figure 900 represent the first derivative of r with respect to z. All curves begin and end with a first derivative of zero because the ends are at local minimum and maximum radii. Figures 902, 904, and 906 correspond to... Figure 7 The first derivatives of the cubic, ex1, and ex2 curves.

[0104] Figure 9 It shows Figure 7 The graph 1000 shows the second derivatives of the three curves (r, z) with respect to z. The second derivative indicates curvature, with a positive second derivative indicating concave curvature and a negative second derivative indicating convex curvature. The absolute value of the second derivative indicates the magnitude of the curvature. Curves 1002, 1004, and 1006 are respectively... Figure 7 The second derivatives of the flow path curves “cubic”, “ex1”, and “ex2” are shown. The cubic polynomial flow path curve has the smoothest curvature change (linear with axial distance). Flow path curve “ex1” also has a monotonically changing curvature; however, its curvature 1004 starts high near the rear blade root 136 and decreases towards the maximum radius. This “pre-loading” curvature results in a smaller convex curvature at the maximum radius than curvature 1002. Flow path curve “ex2” has a larger change at the third curvature 1006, which suppresses the Mach number within the channel of blade 104 and avoids a high convex curvature immediately upstream of the maximum radius. Since curve “ex2” has a relatively low convex curvature, where the combined effect of fan tube acceleration and the increased radius of the flow path curve could otherwise lead to an excessively high Mach number, the third curvature 1006 (“ex2”) is preferred.

[0105] As mentioned earlier, the flight speed of an aircraft is limited by many factors. For propeller-driven aircraft, the propeller plays a crucial role in the speed at which the aircraft can fly. At a high level, the larger the propeller and / or the more blades it has, the faster the aircraft can fly. Unfortunately, while speed is generally proportional to propeller size and the number of blades, so is weight, and larger sizes can pose problems for the installation and feasibility of the propulsion system. For example, as propeller size and / or the number of blades increases, propeller weight typically increases, and larger propellers may struggle to accommodate maintaining ground or fuselage clearance for a given fuselage configuration. Furthermore, at high subsonic flight speeds, a larger number of blades increases congestion in the flow areas of the propeller blade array, a problem given the transonic flow around the blades. In particular, excessive congestion reduces propeller efficiency and the range of maneuverability. Therefore, creating an acceptable aircraft capable of flying at higher sustained speeds (e.g., cruise speed) requires more than just increasing propeller size and / or the number of propeller blades.

[0106] Figure 10 It shows the relationship with Figure 1 The same cross-sectional view is shown, but the front portion of the non-ducted propulsion system 100 (specifically, the rotating element 138) is annotated. The rotating element 138 includes a front housing depicted as a rotator 106 and a plurality of blades 102. Each blade 102 has a blade root 122 and a blade tip 124. The blades 102 are attached to the rotator 106 at the blade root 122. The rotating element 138 may have any suitable number of blades 102. For example, in one embodiment, the rotating element 138 includes 8 to 18 blades. As part of the rotating element 138, the rotator 106 and the blades 102 rotate about a rotation axis 120. The rotator 106 has a foremost point / end / position 108 relative to the arrow 118 indicating the direction of travel of the non-ducted propulsion system 100, and therefore the aircraft.

[0107] The front housing 106 is shaped such that it has a different radius along its axial length, and its shape is observed along a flow path curve 105 formed by the intersection of the rotator surface and a plane including the rotation axis 120 and the foremost point of the front blade root 122. As previously mentioned, the flow path curve is defined by the effective radius at the axial position of the housing's rotation. Therefore, in Figure 10In the example shown, selecting the front blade root 122 for constructing the plane does not affect the flow path curve 105. However, in some embodiments, the front housing 106 may be stationary. Therefore, the convention of specifying the front blade root 122 to define the plane, and thus define the flow path curve 105, applies to other embodiments, as this helps to define the curve for embodiments where the front housing 106 is stationary. The flow path curve 105 of the rotator 106 has a convex position in the axial location, where the radius reaches the maximum axial front of the foremost point of the front blade root 122 of the blade 102, thereby determining the first radius 110 (in Figure 10 (represented as "r1" in the original text). The flow path curve 105 of the rotator 106 has a local minimum position, where the radius reaches a local minimum near the blade 102 as it travels rearward from the convex axis, thus determining the second radius 112 (in...). Figure 10 (represented as "r2" in the original text). Therefore, the axial position of the first radius 110 is located ahead of the axial position of the second radius 112 (i.e., between the axial position of the second radius 112 and the foremost position 108 of the rotator 106). The span of the blade 102 is defined as the distance between the blade root 122 and the blade tip 124. In one embodiment, the blade 102 has a maximum axial distance / width 140 near the middle span (i.e., 50% of the blade height from the blade root to the blade tip). In one embodiment, the blade 102 is fixed to the rotator 106 such that when oriented or configured for cruise operation, the foremost point of the blade root 122 is close to a local minimum with the second radius 112, and such that 0% to 40% of the maximum width 140 is located ahead of the foremost point of the blade root 122. In another embodiment, 20% to 40% of the maximum width 140 is located ahead of the foremost point of the blade root 122.

[0108] In one embodiment, a first radius 110 is larger than a second radius 112, thus defining a protrusion on the rotator 106, the position of which travels axially forward from the root 122 of the front blade, where the radius reaches its maximum value. A first distance 114 (in...) Figure 10 (represented by "z1") is limited between a bulge with a first radius of 110 and a local minimum with a second radius of 112. The second distance (in...) Figure 10The radius (referred to as "z2") is defined between the foremost position 108 of the rotator 106 and a local minimum with a second radius 112. Various parameters (i.e., the first radius 110, the second radius 112, the first distance 114, and the second distance 116) can be specified based on a predetermined speed of the aircraft. That is, suitable values ​​for the various parameters depend on the predetermined speed range of the aircraft. In some embodiments, the predetermined speed of the aircraft is based on the desired airspeed of the aircraft. For example, the predetermined speed of the aircraft can be the speed or speed range at which the aircraft is designed to operate during cruise. The predetermined speed of the aircraft can be any suitable value and can be, for example, between Mach 0.74 and Mach 0.86 (also referred to herein as high subsonic cruise speed). Although the example predetermined speed range of the aircraft is between Mach 0.74 and Mach 0.86, it should be noted that this range can be greater or less than the provided range and has higher and / or lower maximum and minimum values. For example, the predetermined flight Mach number can be between 0.78 and 0.84.

[0109] At a high level, as the predetermined speed of the aircraft increases, the size of the protrusions (i.e., the ratio of the first radius 110 to the second radius 112) that facilitates low pressure loss on the rotator and within the blade 102 assembly increases. Simply put, for a given flight speed, the larger the protrusions, the lower the flow velocity through the blade 102 row. However, as the size of the protrusions increases, the required length of the rotator 106 increases, and the weight of the rotating element 138 increases. Therefore, the size of the protrusions is determined by many factors based on the predetermined speed of the aircraft. Furthermore, the minimum size of the second radius 112 is generally determined by the equipment required for the rotating element 138 (e.g., blade holding hardware, pitch changing mechanism, counterweight system, gearbox, gearbox cooling system, lubrication system, bearings, and drive shaft).

[0110] In one embodiment comprising a front blade assembly and a rear blade assembly, the dimensionless bulge radius is r1 / r2 > 1.029. In other embodiments, the size of the bulge is described by the ratio of a first radius 110 to a second radius 112, and is defined by EQ.4:

[0111]

[0112] Where, r1 is the first radius 110, r2 is the second radius 112 associated with the housing 106, M0 is the Mach number of the aircraft during continuous high-speed flight (i.e., cruising), and A2 is a constant. In one embodiment, the value of A2 is in the range of 1.04 to 1.14. As shown in EQ.4, for each value of A2 within this range, the size of the protrusion (i.e., the ratio of the first radius 110 to the second radius 112) increases as the predetermined speed of the aircraft increases. Specifically, for the minimum value A2 = 1.04, the ratio of the first radius 110 to the second radius 112 is 1.029 at M0 = 0.74, 1.040 at M0 = 0.79, 1.051 at M0 = 0.84, and 1.055 at M0 = 0.86. For the maximum value A2 = 1.14, the ratio of the first radius 110 to the second radius 112 is 1.103 at M0 = 0.74, 1.140 at M0 = 0.79, 1.177 at M0 = 0.84, and 1.192 at M0 = 0.86. Table 4 provides examples of the ratio of the first radius 110 to the second radius 112, where 1.04 < A2 < 1.14 (bold) and 0.74 < M0 < 0.86.

[0113]

[0114] Table 4

[0115] As previously described, the geometry of the spinner 106 can also be described based on the first distance 114 (i.e., the axial distance between the protrusion with the first radius 110 and the local minimum with the second radius 112). In one embodiment consisting of a front blade assembly and a rear blade assembly, the dimensionless axial distance z1 / r2 < 1.522. In another embodiment, the first distance 114 is described according to the ratio of the first distance 114 to the second radius 112 and is defined by EQ.5:

[0116]

[0117] Where, z1 is the first distance 114, r2 is the second radius 112, M0 is the Mach number of the aircraft during sustained high-speed flight (such as cruising), and B2 is a value. In one embodiment, the value of B2 is in the range of 0.78 to 1.18. As shown in EQ.5, for each value of B2 within this range, the first distance 114 increases as the predetermined speed of the aircraft increases. Simply put, the length of the spinner 106 increases as the predetermined speed of the aircraft increases. Specifically, for the minimum value B2 = 0.78, the ratio of the first distance 114 to the second radius 112 is 0.641 at M0 = 0.74, 0.780 at M0 = 0.79, 0.938 at M0 = 0.84, and 1.006 at M0 = 0.86. For the maximum value B2 = 1.18, the ratio of the first distance 114 to the second radius 112 is 0.970 at M0 = 0.74, 1.180 at M0 = 0.79, 1.419 at M0 = 0.84, and 1.522 at M0 = 0.86. Table 5 provides examples of the ratio of the first distance 114 to the second radius 112, where 0.78 < B2 < 1.18 (bold) and 0.74 < M0 < 0.86.

[0118]

[0119] Table 5

[0120] As previously mentioned, the geometry of the spinner 106 can also be described based on the second distance 116 (i.e., the distance between the foremost position 108 of the spinner 106 and the local minimum having the second radius 112). In one embodiment consisting of a front blade assembly and a rear blade assembly, the dimensionless axial distance z2 / r2 < 4.115. In one embodiment, the second distance 116 is described according to the ratio between the second distance 116 and the second radius 112, and is defined by EQ.6:

[0121]

[0122] Where, z2 is the second distance 116, r2 is the second radius 112, M0 is the Mach number of the aircraft during sustained high-speed flight (such as cruising), and C2 is a value. In one embodiment, the value of C2 ranges from 2.19 to 3.19. As shown in EQ.6, the second distance 116 increases as the predetermined speed of the aircraft increases. Simply put, the length of the spinner 106 increases as the predetermined speed of the aircraft increases. Specifically, for the minimum value C2 = 2.19, the ratio of the second distance 116 to the second radius 112 is 1.800 at M0 = 0.74, 2.190 at M0 = 0.79, 2.633 at M0 = 0.84, and 2.825 at M0 = 0.86. For the maximum value C2 = 3.19, the ratio of the second distance 116 to the second radius 112 is 2.622 at M0 = 0.74, 3.190 at M0 = 0.79, 3.835 at M0 = 0.84, and 4.115 at M0 = 0.86. Table 6 provides examples of the ratio of the second distance 216 to the second radius 112, where 2.19 < C2 < 3.19 (bold) and 0.74 < M0 < 0.86.

[0123]

[0124] Table 6

[0125] Although Figure 10 the discussion describes a ducted propulsion system for propelling an aircraft consistent with the teachings herein, Figure 11 the discussion provides more details about the graph of geometric dimension values of the spinner of such a ducted propulsion system.

[0126] Figure 11 is FIG. 200 depicting the external flow path shape of the spinner of a ducted propulsion system according to some embodiments. The Y-axis 204 represents the spinner radius r / r2 normalized by the second radius 112, which is at the local minimum within the axial range closest to the blade 102 having the first radius 110. The X-axis 202 represents the axial distance z / r2 of the axial position from the second radius 112 (i.e., the local minimum) normalized by the second radius 112.

[0127] Figure 200 illustrates the shapes of the front housing or rotator 106 at different cruise Mach numbers M0. Specifically, Figure 200 includes a first figure 206, a second figure 208, a third figure 210, and a fourth figure 212. Each of the first figure 206, the second figure 208, the third figure 210, and the fourth figure 212 originates from the same values ​​A2 = 1.09, B2 = 0.98, and C2 = 2.69, but for different cruise Mach numbers M0. The first figure 206 corresponds to M0 = 0.70, the second figure 208 corresponds to M0 = 0.74, the third figure 210 corresponds to M0 = 0.79, and the fourth figure 212 corresponds to M0 = 0.84. As can be seen from Figure 200, which depicts the general shape and relative dimensions of the rotator, the ratio of the first radius to the second radius and the ratio of the second distance to the second radius increase with increasing predetermined speed.

[0128] In addition to specifying the front shell size ratio, this paper describes further constraints on the shape of the flow path curve. The hyperelliptic equation below can provide an appropriate curvature distribution along the flow path curve 105 to avoid excessive Mach numbers along the front shell portion in front of the bulge. When specifying the shape of the rotator using the obtained r1, z1, and z2, the hyperelliptic expression provides optional boundaries on the flow path curve 105 in front of the bulge. EQ.7 of the hyperellipse relating the axial coordinate z to the radius r is given below.

[0129] Or, equivalently,

[0130] In EQ.7, the exponents p and q define the shape of the curves ahead of the bulges of the ratios r1 / r2, z1 / r2, and z2 / r2 as determined by EQS.4, 5, and 6 above. Figure 12 Provided with Figure 11Figure 200 in [reference] is similar to Figure 1200. Therefore, the X-axis 202, Y-axis 204, and curve 210 in Figure 1200 are the same as those in Figure 200. Curves 1208 and 1212 conform to the same ratio as curve 210 determined by EQS 4, 5, and 6. However, curves 1208 and 1212 that define the applicable point range of the flow path curve 105 are determined via EQ.7 by using the values of exponents p and q. Curve 1208 with exponents p = 1.5 and q = 2.0 forms a lower limit at the appropriate points of the flow path curve 105 in front of the bulge. Curve 1212 with exponents p = 3.0 and q = 3.5 forms an upper limit of the appropriate points of the flow path curve 105 in front of the bulge. Therefore, within the axial range from the bulge to the foremost end 108 of the front housing 106, EQ.7 with the range of exponents p and q provides a point band or point range to define the shape of the front housing 106. Curve 210 fits well with EQ.7 using exponents p = 2.0 and q = 3.0. Therefore, the lower limit is selected to conform to the exponent ranges 1.5 < p < 2.0 and 2.0 < q < 3.0, while the upper limit is selected to conform to the exponent ranges 2.0 < p < 3.0 and 3.0 < q < 3.5. At least for some cruise flight Mach numbers M0, such as 0.79 shown in Figure 210, a low-loss flow path curve can be obtained within more limited bounds, such that the lower limit on the flow path curve is constrained within the range of 1.7 < p < 2.0 and 2.5 < q < 3.0, while the upper limit on the flow path curve is constrained within the range of 2.0 < p < 2.5 and 3.0 < q < 3.3.

[0131] In some configurations, the above spinner shape parameters may be particularly advantageous for a range of dimensionless cruise fan net thrust parameters. The thrust parameter is the same as defined previously: The thrust parameter can be greater than or equal to 0.060 (e.g., greater than 0.080 or greater than 0.084).

[0132] It should be recognized that the front housing 106 or the rotator need not be axisymmetric about the propeller's axis of rotation. For example, at axial positions near the second radius of the plurality of blades, the distance between the rotator or hub surfaces can vary in the circumferential direction to accommodate blade attachment or variable pitch mechanisms. As previously stated, for an axial position of the front housing 106 rotating about the axis of rotation 120, if a rotator is present, the radius (e.g., the second radius) is defined as the "effective" radius of a circle having the same cross-sectional area of ​​the rotator perpendicular to the axis of rotation. Therefore, the term "radius" as used in the specification and claims refers to the radius of a circle having the cross-sectional area of ​​the rotator at that axial position. However, for a stationary front housing 106, as in the case of a non-piped propulsion system in which the front blade assembly is stationary and the rear blade assembly rotates, the flow path curve 105 corresponds to the line of intersection of the front housing with a plane including the axis of rotation and the foremost point of the front blade root 122. If the front blade 102 has a variable pitch, the foremost point corresponds to the blade orientation that positions the foremost point at its foremost position, possibly approximating cruise or design point conditions. In this case, the flow path curve 105 disclosed herein may correspond to one, more than one, or all of the blade roots 122. When the foremost point of the front blade root 122 is not attached to the front housing 106, for example, when there is a gap between the front blade root 122 and the front housing 106 to allow for pitch variation, or when the front blade 102 is attached to the frame and suspended on the front housing 106, then curve 105 passes through the nearest point on the surface of the front housing 106 to the foremost point of the front blade root 122.

[0133] In some embodiments, the rotating element of a non-pipeline propulsion system for propelling an aircraft includes a plurality of blades fixed to a rotator, wherein the rotator is configured to rotate about a rotation axis, wherein the rotator includes a first radius and a second radius, wherein the second radius is close to the plurality of blades and the first radius extends forward from the second radius, wherein the ratio of the first radius to the second radius is in the range of 1.029 to 1.192, and wherein the aircraft is configured to travel at a predetermined speed.

[0134] In some embodiments, the rotating element of a non-pipeline propulsion system for propelling an aircraft includes a plurality of blades fixed to a rotator, wherein the rotator is configured to rotate about a rotation axis, wherein a flow path curve on the rotator includes a first radius and a second radius, wherein the first radius is at a bulge or maximum radius in front of the associated plurality of blades, wherein the second radius is at a local minimum behind the bulge, wherein a first distance is defined between the axial position of the bulge and the local minimum, and wherein the second distance is defined between the foremost point of the rotator and the axial position of the local minimum, wherein the ratio of the first radius to the second radius is in the range of 1.029 to 1.192, wherein the ratio of the first distance to the second radius is in the range of 0.641 to 1.522, wherein the ratio of the second distance to the second radius is in the range of 1.800 to 4.115, wherein the aircraft is configured to travel at a predetermined speed. Figure 13 This is a flowchart of a method 1300 for operating a non-pipeline propulsion system for propelling an aircraft. The non-pipeline propulsion system includes a rotator and multiple blades fixed to the rotator. The method includes step 1302 of rotating the rotator about a rotation axis and step 1304 of operating the aircraft at a predetermined speed greater than or equal to Mach 0.74. The rotator may be relative to... Figure 1 and Figure 2 The rotator is constructed as described herein. For example, the rotator may include a first radius and a second radius, wherein the second radius is close to a plurality of blades, and the first radius extends forward from the second radius, wherein the ratio of the first radius to the second radius is greater than 1.029. Furthermore, the ratio of the first radius to the second radius may be defined by EQ 4:

[0135]

[0136] Where r1 is the first radius, r2 is the second radius, M0 corresponds to the aircraft's intended sustained high speed (such as cruise), and A2 is a value in the range of 1.04 to 1.14.

[0137] Furthermore, the first distance is defined between an axial position corresponding to a first radius and an axial position corresponding to a second radius, and the ratio of the first distance to the second radius is less than 1.522. Additionally, the ratio of the first distance to the second radius can be defined by EQ.5:

[0138]

[0139] Where z1 is the first distance, r2 is the second radius, M0 corresponds to the aircraft's intended sustained high speed (e.g., cruise), and B2 is a value in the range of 0.78 to 1.18.

[0140] In addition, the second distance is defined between the foremost end of the spinner and the axial position corresponding to the second radius, and the ratio of the second distance to the second radius is less than 4.115. Further, the ratio of the second distance to the second radius can be defined by EQ.6:

[0141]

[0142] where z2 is the second distance, r2 is the second radius, M0 corresponds to a predetermined sustained high speed (such as cruise) of the aircraft, and C2 is a value within the range of 2.19 to 3.19.

[0143] A ducted propulsion system for an aircraft configured for high subsonic cruise, comprising: a rotational axis; a front vane assembly consisting of a plurality of front vanes; a rear vane assembly consisting of a plurality of rear vanes; a front housing; a rear housing; wherein each front vane and each rear vane includes a vane root near the rotational axis and a vane tip away from the rotational axis; wherein the flow path curve corresponds to the intersection line of the outer surface of the rear housing and a plane containing the rotational axis and the last point of the rear vane root; wherein, for the flow path curve, the axial direction z is parallel to the rotational axis, and the radius r is the distance from the rotational axis; wherein, on the flow path curve, the position of the bulge with radius r b is found by traveling backward from the last point on the rear vane root to the position where the first radius reaches its maximum value; wherein, on the flow path curve, the position of the local minimum with radius r h is found by traveling forward from the bulge position to the nearest point where the second radius stops decreasing within the axial range of the rear vane root; and wherein the ratio r b / r h > 1.081.

[0144] The ducted propulsion system according to any of the preceding clauses, wherein the axial distance z b is between the bulge position and the local minimum, and wherein the ratio z b / r h < 2.103.

[0145] The ducted propulsion system according to any of the preceding clauses, wherein the position with radius r m is axially midway between the bulge position and the local minimum, and wherein the ratio

[0146] The ducted propulsion system according to any of the preceding clauses, wherein the aircraft is configured for a cruise flight Mach number of 0.74 < M0 < 0.86, and wherein, Among them 1.11 <A1<1.31。

[0147] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 1.23 <B1<1.63。

[0148] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein Of which 0.59 <C1<0.79。

[0149] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 1.16 <A1<1.31。

[0150] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 1.23 <B1<1.53。

[0151] According to any of the foregoing clauses, in the non-pipeline propulsion system, 0.64 <C1<0.79。

[0152] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 1.16 <A1<1.26。

[0153] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 1.33 <B1<1.53。

[0154] According to any of the foregoing clauses, in the non-pipeline propulsion system, 0.64 <C1<0.74。

[0155] According to any of the foregoing clauses, the non-pipeline propulsion system wherein the aircraft is configured to have dimensionless cruise thrust parameters. During cruise operations:

[0156] (i)F net It is the net thrust of the fan.

[0157] (ii)ρ0 is the ambient air density.

[0158] (iii) V0 is the flight speed.

[0159] (iv)A an It is the annular area of ​​the fan duct entering the fan, and

[0160] (v)

[0161] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein

[0162] According to any of the foregoing clauses, in a non-pipeline propulsion system, the front blade assembly and the front housing rotate about the axis of rotation, and the rear blade assembly and the rear housing are stationary.

[0163] According to any of the foregoing clauses, in a non-pipeline propulsion system, the flow path curve further corresponds to the respective last point at the root of two or more rear blades.

[0164] According to any of the foregoing clauses, in a non-pipeline propulsion system, the flow path curve further corresponds to the corresponding last point at the root of at least half of the rear blades.

[0165] According to any of the preceding clauses, in a non-pipeline propulsion system, the front blade assembly and the front housing rotate about the axis of rotation, wherein the rear blade assembly and a portion of the rear housing to which the plurality of rear blades are fixed rotate about the axis of rotation, and wherein a third radius at a given axial position of rotation of the rear housing is an effective radius, the effective radius being a fourth radius of a circle having the same cross-sectional area perpendicular to the axis of rotation at that axial position.

[0166] According to any of the preceding clauses, in a non-pipeline propulsion system, the front blade assembly and the front housing are stationary, wherein the rear blade assembly and a portion of the rear housing to which the plurality of rear blades are fixed rotate about the axis of rotation, and wherein a third radius at a given axial position of rotation of the rear housing is an effective radius, the effective radius being a fourth radius of a circle having the same cross-sectional area perpendicular to the axis of rotation at that axial position.

[0167] According to any of the foregoing clauses, the non-pipeline propulsion system has more than 4 blades in the front blade assembly, more than 4 blades in the rear blade assembly, and the ratio of the number of blades in the front blade assembly to the number of blades in the rear blade assembly is between 2:5 and 2:1.

[0168] In any of the foregoing clauses, the number of blades in the front blade assembly is between 8 and 18.

[0169] According to any of the foregoing clauses, in a non-pipeline propulsion system, the difference between the number of blades in the front blade assembly and the number of blades in the rear blade assembly is between 2 and -2.

[0170] According to any of the foregoing clauses, in a non-pipeline propulsion system, wherein, compared to r b / r h >1.118.

[0171] The non-ducted propulsion system according to any of the preceding clauses, wherein the axial distance z b is between the raised position and the local minimum, and wherein the ratio z b / r h < 1.974.

[0172] The non-ducted propulsion system according to any of the preceding clauses, wherein the position with a radius of r m is axially midway between the raised position and the local minimum, and wherein the ratio

[0173] The non-ducted propulsion system according to any of the preceding clauses, wherein the ratio r b / r h < 1.424.

[0174] A non-ducted propulsion system for an aircraft configured for high subsonic cruise, comprising: a rotational axis; a front blade assembly consisting of a plurality of front blades; a rear blade assembly consisting of a plurality of rear blades; a front housing; a rear housing; wherein, for each front blade and each rear blade, there is a blade root near the rotational axis and a blade tip far from the rotational axis; wherein the flow path curve corresponds to the intersection line of the outer surface of the front housing and the plane containing the rotational axis and the foremost point of the front blade root; wherein, for the flow path curve, the axial direction z is parallel to the rotational axis, and the radius r is the first distance from the rotational axis; wherein the raised position with a radius r1 on the flow path curve is found by moving forward from the foremost point on the front blade root to the position where the first radius reaches its maximum; wherein the local minimum with a radius r2 on the flow path curve is found by moving backward from the raised position to the nearest point where the second radius stops decreasing within the axial range of the front blade root, and wherein the ratio r1 / r2 > 1.029.

[0175] The non-ducted propulsion system according to any of the preceding clauses, wherein the axial distance z1 is between the raised position and the local minimum, and wherein the ratio z1 / r2 < 1.522.

[0176] The non-ducted propulsion system according to any of the preceding clauses, wherein the axial distance z2 is between the foremost end of the front housing and the local minimum, and wherein the ratio z2 / r2 < 4.115.

[0177] The non-ducted propulsion system according to any of the preceding clauses, wherein the aircraft is configured for a cruise flight Mach number of 0.74 < M0 < 0.86, and wherein Of which 1.04 <A2<1.14。

[0178] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein Of which 0.78 <B2<1.18。

[0179] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 2.19 <C2<3.19。

[0180] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 1.06 <A2<1.14。

[0181] According to any of the foregoing clauses, in the non-pipeline propulsion system, 0.78 <B2<1.08。

[0182] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein, 2.19 <C2<2.99。

[0183] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein 1.06 <A2<1.12。

[0184] According to any of the foregoing clauses, in the non-pipeline propulsion system, 0.88 <B2<1.08。

[0185] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein, 2.39 <C2<2.99。

[0186] According to any of the foregoing clauses, the non-pipeline propulsion system wherein the aircraft is configured to have dimensionless cruise thrust parameters. During cruise operations:

[0187] (i)F net It is the net thrust of the fan.

[0188] (ii)ρ0 is the ambient air density.

[0189] (iii) V0 is the flight speed.

[0190] (iv)A an It is the annular area of ​​the fan duct entering the fan, and

[0191] (v)

[0192] According to any of the foregoing clauses, in the non-pipeline propulsion system, wherein

[0193] According to any of the foregoing clauses, in a non-pipeline propulsion system, the front blade assembly and the front housing are stationary, and the rear blade assembly and a portion of the rear housing to which the plurality of rear blades are attached rotate about the axis of rotation.

[0194] According to any of the foregoing clauses, in a non-pipeline propulsion system, the flow path curve further corresponds to the foremost point of the root of two or more front blades.

[0195] According to any of the foregoing clauses, in a non-pipeline propulsion system, the flow path curve further corresponds to the corresponding foremost point at the root of at least half of the front blades.

[0196] According to any of the foregoing clauses, in a non-pipeline propulsion system, the front blade assembly and the front housing rotate about the axis of rotation, wherein the rear blade assembly and a portion of the rear housing to which the plurality of rear blades are fixed rotate about the axis of rotation, and wherein a third radius at a given axial position of rotation of the front housing is an effective radius, the effective radius being a fourth radius of a circle having the same cross-sectional area perpendicular to the axis of rotation at that axial position.

[0197] According to any of the preceding clauses, in a non-pipeline propulsion system, the front blade assembly and the front housing rotate about the axis of rotation, wherein the rear blade assembly and the rear housing are stationary, and wherein a third radius at a given axial position of rotation of the front housing is an effective radius, the effective radius being a fourth radius of a circle having the same cross-sectional area perpendicular to the axis of rotation at that axial position.

[0198] According to any of the foregoing clauses, the non-pipeline propulsion system has more than 4 blades in the front blade assembly, more than 4 blades in the rear blade assembly, and the ratio of the number of blades in the front blade assembly to the number of blades in the rear blade assembly is between 2:5 and 2:1.

[0199] In any of the foregoing clauses, the number of blades in the front blade assembly is between 8 and 18.

[0200] According to any of the foregoing clauses, in a non-pipeline propulsion system, the difference between the number of blades in the front blade assembly and the number of blades in the rear blade assembly is between 2 and -2.

[0201] According to any of the foregoing clauses, in a non-pipeline propulsion system, the ratio r1 / r2 > 1.044.

[0202] A ducted propulsion system according to any of the preceding clauses, wherein the axial distance z1 is between the raised position and the local minimum, and wherein z1 / r2 < 1.393.

[0203] A ducted propulsion system according to any of the preceding clauses, wherein the axial distance z2 is between the foremost end of the front housing and the local minimum, and wherein z2 / r2 < 3.857.

[0204] A ducted propulsion system according to any of the preceding clauses, wherein the span is the second distance between the blade root and the blade tip, wherein the plurality of front blades in the front blade assembly are oriented for cruise operation, wherein the plurality of front blades in the front blade assembly have a maximum axial width near the mid-span, and wherein 0% to 40% of the maximum axial width is in front of the foremost point of the front blade root.

[0205] A ducted propulsion system according to any of the preceding clauses, wherein the origin of the flow path curve (z,r) coordinate system is at the axial position of the local minimum, wherein the axial coordinate z increases in the forward direction, and wherein the curve in front of the raised portion (z > z1) lies within the lower and upper limits defined by where the exponents of the lower limit are 1.5 < p < 2.0 and 2.0 < q < 3.0, and wherein the exponents of the upper limit are 2.0 < p < 3.0 and 3.0 < q < 3.5.

[0206] A ducted propulsion system according to any of the preceding clauses, wherein the exponents of the lower limit are 1.7 < p < 2.0 and 2.3 < q < 3.0, and wherein the exponents of the upper limit are 2.0 < p < 2.5 and 3.0 < q < 3.3.

[0207] A ducted propulsion system for an aircraft configured for high subsonic cruise, comprising: a rotational axis; a front blade assembly comprising a plurality of front blades; a front housing; wherein for each blade, there is a blade root near the rotational axis and a blade tip away from the rotational axis; wherein the flow path curve corresponds to the intersection of the outer surface of the front housing with a plane containing the rotational axis and the foremost point of the front blade root; wherein for the flow path curve, the axial direction z is parallel to the rotational axis, and the radius r is the distance from the rotational axis; wherein the raised position on the flow path curve having a radius r1 is found by traveling forward from the foremost point on the front blade root to the position where the first radius reaches a maximum; wherein the local minimum on the flow path curve having a radius r2 is found by traveling backward from the raised position to the nearest point where the second radius stops decreasing, and wherein r1 / r2 > 1.066.

[0208] According to any of the foregoing clauses, the non-pipeline propulsion system wherein the axial distance z1 is between the convex position and the local minimum, and wherein the ratio z1 / r2 < 1.522.

[0209] According to any of the foregoing clauses, in a non-pipeline propulsion system, the axial distance z2 is between the foremost point of the front housing and the local minimum, and wherein the ratio z2 / r2 < 4.115.

Claims

1. A non-pipeline propulsion system for an aircraft configured for high subsonic cruise, characterized in that, include: axis of rotation; A front blade assembly, which comprises a plurality of front blades; A rear blade assembly, which is composed of a plurality of rear blades; Front housing; Rear housing; Each front blade and each rear blade includes a blade root near the axis of rotation and a blade tip away from the axis of rotation; The flow path curve corresponds to the intersection line between the outer surface of the rear housing and the plane containing the rotation axis and the last point of the rear blade root; Wherein, for the flow path curve, the axial direction Parallel to the axis of rotation, and radius It is the distance from the axis of rotation; Wherein, the flow path curve has a radius The protrusion position is found by moving backward from the last point on the root of the rear blade to the position where the first radius reaches its maximum value; Wherein, the flow path curve has a radius The local minimum is found by moving forward from the protrusion to the nearest point where the second radius stops decreasing within the axial range at the root of the rear blade; Among them, compared ;and Among them, axial distance Between the protruding position and the local minimum, and wherein the ratio is... .

2. The non-pipeline propulsion system according to claim 1, characterized in that, in, radius is The position is axially located midway between the protruding position and the local minimum, and wherein, compared to .

3. The non-pipeline propulsion system according to claim 2, characterized in that, in, The aircraft is configured to have a cruising Mach number. , and among them ,in .

4. The non-pipeline propulsion system according to claim 3, characterized in that, in, ,in 。 5. The non-pipeline propulsion system according to claim 4, characterized in that, in, ,in 。 6. The non-pipeline propulsion system according to claim 5, characterized in that, in, 。 7. The non-pipeline propulsion system according to claim 6, characterized in that, in, 。 8. The non-pipeline propulsion system according to claim 7, characterized in that, in, 。 9. The non-pipeline propulsion system according to claim 8, characterized in that, in, 。 10. The non-pipeline propulsion system according to claim 9, characterized in that, in, 。 11. The non-pipeline propulsion system according to claim 10, characterized in that, in, 。 12. The non-pipeline propulsion system according to claim 5, characterized in that, in The aircraft is configured to have dimensionless cruise thrust parameters. During cruise operations i. It is the net thrust of the fan. ii. It is ambient air density. iii. It is flight speed. iv. It is the annular area of ​​the fan duct entering the fan, and v. 。 13. The non-pipeline propulsion system according to claim 12, characterized in that, in 。 14. The non-pipeline propulsion system according to claim 5, characterized in that, in, The front blade assembly and the front housing rotate about the axis of rotation, while the rear blade assembly and the rear housing are stationary.

15. The non-pipeline propulsion system according to claim 14, characterized in that, One of the following: the flow path curve further corresponds to the corresponding last point of two or more rear blade roots; or the flow path curve further corresponds to the corresponding last point of at least half of the rear blade roots.

16. The non-pipeline propulsion system according to claim 5, characterized in that, One of the following: The front blade assembly and the front housing rotate about the axis of rotation, wherein the rear blade assembly and a portion of the rear housing to which the plurality of rear blades are fixed rotate about the axis of rotation, and wherein a third radius at a given axial position of rotation of the rear housing is an effective radius, the effective radius being a fourth radius of a circle having the same cross-sectional region perpendicular to the axis of rotation at said axial position; or The front blade assembly and the front housing are stationary, wherein the rear blade assembly and a portion of the rear housing to which the plurality of rear blades are fixed rotate about the axis of rotation, and wherein a third radius at a given axial position of rotation of the rear housing is an effective radius, the effective radius being a fourth radius of a circle having the same cross-sectional area perpendicular to the axis of rotation at the axial position.

17. The non-pipeline propulsion system according to claim 5, characterized in that, in, The number of blades in the front blade assembly is greater than 4, the number of blades in the rear blade assembly is greater than 4, and the ratio of the number of blades in the front blade assembly to the number of blades in the rear blade assembly is between 2:5 and 2:

1.

18. The non-pipeline propulsion system according to claim 17, characterized in that, in, The number of blades in the front blade assembly is between 8 and 18.

19. The non-pipeline propulsion system according to claim 18, characterized in that, in, The difference between the number of blades in the front blade assembly and the number of blades in the rear blade assembly is between 2 and -2.

20. The non-pipeline propulsion system according to claim 1, characterized in that, At least one of the following: The ratio ;or Compare ;and Among them, axial distance Between the protruding position and the local minimum, and wherein, compared to And among them, the radius is The position is axially located midway between the protruding position and the local minimum, and wherein, compared to .

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