Design method of hinge spoiler type front duct ejector with pneumatic valve

Abstract

The invention relates to the technical field of aero-engines, in particular to a method for designing a hinge spoiler type front duct ejector with a pneumatic valve, which comprises the following steps of: determining geometric parameters of the front duct ejector and a distance range corresponding to an inner duct and an outer duct; designing an initial two-dimensional pneumatic molded surface of the front duct ejector; obtaining a target two-dimensional pneumatic profile; the final radius of the spoiler is determined, and the spoiler is designed; and the three-dimensional structure of the front duct ejector is obtained. The aerodynamic performance of the front duct ejector under multiple working conditions is comprehensively considered, the design efficiency is improved, the weight and strength requirements of the spoiler are reduced, and collision or abrasion, caused by thermal expansion or vibration of materials, between the spoiler and the outer duct wall face is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengines, and in particular to a design method for a hinged spoiler type front duct ejector with a pneumatic valve. Background Art

[0002] The adaptive cycle engine has become an ideal power unit for the next generation of fighter jets and future supersonic passenger aircraft with its efficient bypass ratio adjustment capability and good flow retention capability. The front duct ejector is a key component of the adaptive cycle engine. Its function is to control the mixing of the inner and outer duct airflows at a reasonable Mach number through geometric adjustment, so that the physical parameters of the outlet airflow are uniform and the mixing loss is minimized. The front duct ejector is an important component for the adaptive cycle engine to achieve flow regulation and maintain high-efficiency operation. The success or failure of its design will have a great impact on the overall performance of the engine.

[0003] Traditional hinged spoiler type front duct ejectors usually close the outer duct by contacting the spoiler with the outer duct wall. However, the front duct ejector works in a high temperature and strong vibration environment. The thermal expansion or vibration of the material may cause the spoiler to collide and wear with the outer duct wall, and the spoiler will also be insufficient in flexibility. That is, the traditional method focuses on adjusting the geometric shape through experiments and experience, which is difficult to take into account the aerodynamic performance of the front duct ejector under different working conditions, and there are problems of low design efficiency and insufficient performance optimization.

[0004] Therefore, it is necessary to provide a design method for a hinged spoiler type front duct ejector with a pneumatic valve to solve the above problems. Summary of the invention

[0005] The invention provides a design method of a hinge spoiler type front duct ejector with a pneumatic valve to solve the existing problems.

[0006] The design method of a hinge spoiler type front duct ejector with a pneumatic valve of the present invention adopts the following technical scheme, including: According to the engine design requirements, determine the geometric parameters of the front duct ejector and the corresponding spacing range of the inner duct and the outer duct. The geometric parameters include: the maximum area of ​​the inner duct, the minimum area of ​​the inner duct, the distance from the lower wall of the inner duct inlet to the engine rotation axis, the spacing from the upper wall of the inner duct to the lower wall of the outer duct, the axial distance from the inner duct inlet to the spoiler hinge, the maximum area of ​​the outer duct, the minimum area of ​​the outer duct, the axial distance from the outer duct inlet to the spoiler hinge, and the total axial length of the front duct ejector; Based on the principle that the sum of the mixing areas of the inner and outer parts of the front duct ejector at the mixing point remains unchanged, and according to the geometric parameters of the front duct ejector, the initial two-dimensional aerodynamic profile of the front duct ejector is designed; Detecting whether there is a local shock wave on the initial two-dimensional aerodynamic profile, and performing smooth transition processing on the position of the initial two-dimensional aerodynamic profile where the local shock wave exists to obtain a target two-dimensional aerodynamic profile; Obtain the ejector performance of the target two-dimensional aerodynamic profile under various working conditions, determine the minimum radius of the spoiler according to the ejector performance and ejector performance requirements, determine the final radius of the spoiler according to the minimum radius and maximum radius of the spoiler, and design the spoiler, wherein the working conditions include: the working condition of the spoiler at the minimum area of ​​the outer culvert, the working condition of the spoiler at the maximum area of ​​the outer culvert, and the working condition of the spoiler at the middle area of ​​the outer culvert; The three-dimensional structure of the front duct ejector is obtained based on the target two-dimensional aerodynamic profile and the spoiler with the final radius.

[0007] Preferably, based on the principle that the sum of the mixing areas of the inner and outer parts of the front duct ejector at the mixing point remains unchanged, and according to the geometric parameters of the front duct ejector, the steps of designing the initial two-dimensional aerodynamic profile of the front duct ejector are as follows: Draw a horizontal line to represent the rotation axis of the aircraft engine, determine the position of the upper wall of the outer duct according to the distance between the lower wall of the inner duct and the rotation axis and the maximum spacing of the inner duct, the spacing between the upper wall of the inner duct and the lower wall of the outer duct, and the maximum spacing of the outer duct, determine the position of the lower wall of the front duct ejector outlet according to the mixing area and the position of the upper wall of the outer duct, and determine the position of the lower wall of the outer duct according to the maximum area of ​​the outer duct and the position of the upper wall of the outer duct; According to the spacing range corresponding to the outer connotation and the inner connotation, the uppermost swing position and the lowermost swing position of the spoiler, that is, the swing range of the spoiler, are determined; According to the preset spoiler radius and the swing range of the spoiler, the spoiler is projected onto the lower wall surface of the outlet to determine the intersection point between the lower wall surface of the inner duct and the lower wall surface of the outlet of the front duct ejector; When the spoiler is swung to the uppermost swing position, a vertical line is drawn through the root of the spoiler at this moment, and the distance is the maximum spacing. The position of the vertical line is the cross-sectional position of the root of the spoiler. According to the distance from the upper wall of the inner culvert to the lower wall of the outer culvert, the position of the inner culvert inlet and the maximum area of ​​the inner culvert, determine the inlet section of the inner culvert and the axial relative position of the inner culvert inlet section to the inlet section of the outer culvert; The curved spline is generated according to the spoiler root section, the inner inlet section and the axial relative position of the inner inlet section to the outer inlet section, and the upper and lower walls of the inner section are determined according to the maximum area of ​​the inner section to obtain the initial two-dimensional aerodynamic surface.

[0008] Preferably, the step of obtaining the spacing range corresponding to the connotation and the exogenous connotation is: Obtain the spacing range of the connotation according to the maximum connotation area, the minimum connotation area, the distance between the lower wall of the connotation and the engine rotation axis, and the spacing between the upper wall of the connotation and the lower wall of the outer connotation; The spacing range of the culvert is obtained according to the maximum area of ​​the culvert, the minimum area of ​​the culvert, the distance between the lower wall of the culvert and the engine rotation axis, the maximum spacing of the inner culvert, and the spacing from the upper wall of the inner culvert to the lower wall of the culvert.

[0009] Preferably, the steps of obtaining the connotation spacing range are: According to the maximum area of ​​the connotation and the distance between the lower wall of the connotation and the engine rotation axis, the maximum spacing of the connotation is obtained; The minimum spacing of the inner lining is obtained according to the minimum area of ​​the inner lining, the distance between the lower wall of the inner lining and the rotation axis of the engine, and the spacing between the upper wall of the inner lining and the lower wall of the outer lining; The spacing range of the connotation is obtained according to the minimum spacing and the maximum spacing of the connotation.

[0010] Preferably, the steps of obtaining the outer circumference spacing range are: The maximum spacing of the culvert is obtained according to the maximum area of ​​the culvert, the distance between the lower wall of the culvert and the engine rotation axis, the maximum spacing of the inner culvert, and the spacing from the upper wall of the inner culvert to the lower wall of the culvert; Obtain the minimum spacing of the culvert according to the minimum area of ​​the culvert, the maximum spacing of the culvert, the distance between the lower wall of the culvert and the engine rotation axis, the maximum spacing of the inner culvert, and the spacing from the upper wall of the inner culvert to the lower wall of the culvert; The spacing range of the culvert is obtained according to the minimum spacing and the maximum spacing of the culvert.

[0011] Preferably, the steps of obtaining the minimum spacing and the maximum spacing of the connotation are: The expression of the minimum spacing is:

[0012] The expression of the maximum spacing is:

[0013] In the formula, is the minimum spacing of connotation; is the maximum spacing of connotation; is the distance between the lower wall and the engine rotation axis; is the maximum area of ​​connotation; is the minimum area of ​​connotation; It is the distance from the upper wall of the inner lining to the lower wall of the outer lining.

[0014] Preferably, the steps of obtaining the minimum spacing and the maximum spacing of the entanglement are: The expression of the minimum spacing of the culvert is:

[0015] The expression of the maximum spacing of the outer culvert is:

[0016] In the formula, is the minimum spacing of the culvert; is the maximum spacing of the culvert; is the maximum spacing of connotation; is the distance between the lower wall and the engine rotation axis; It is the maximum external area; is the minimum external area; It is the distance from the upper wall of the inner lining to the lower wall of the outer lining.

[0017] Preferably, the step of determining the minimum radius of the spoiler is: The ejector performance is the total pressure recovery coefficient, wherein the total pressure recovery coefficient of the front duct ejector is obtained according to the pressure and flow at the inlet and outlet corresponding to the inner and outer ducts of the front duct ejector; The spoiler radius is reduced multiple times and the flow field is re-simulated until the spoiler radius is reduced to a certain value and the outer duct cannot be completely closed or the ejector performance does not meet the performance requirements. The last spoiler radius is used as the minimum spoiler radius.

[0018] Preferably, the step of determining the final radius of the spoiler according to the minimum radius and the maximum radius of the spoiler is:

[0019] In the formula, is the final radius of the spoiler; is the proportionality coefficient; is the minimum radius of the spoiler; is the maximum radius of the spoiler.

[0020] Preferably, the steps of obtaining the three-dimensional aerodynamic profile of the ejector based on the target two-dimensional aerodynamic profile and the spoiler of the final radius are: The target two-dimensional aerodynamic surface is rotated around the main axis of the engine to generate a three-dimensional annular section; the spoiler with the final radius is connected to the front end of the intersection of the inner duct and the outer duct through a hinge to obtain the three-dimensional structure of the front duct ejector.

[0021] The beneficial effects of the present invention are: The two-dimensional design of the front duct ejector is performed by keeping the mixing area of ​​the inner and outer ducts unchanged, and the pressure difference between the inlet and outlet of the front duct ejector is used to form a pneumatic valve to close the outer duct. The aerodynamic performance of the front duct ejector in multiple working conditions can be comprehensively considered, the design efficiency can be improved, the weight and strength requirements of the spoiler can be reduced, and the collision or wear between the spoiler and the outer duct wall due to thermal expansion or vibration of the material can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a flow chart of a design method of a hinge spoiler type front duct ejector with a pneumatic valve of the present invention; Figure 2 It is a schematic diagram of a two-dimensional aerodynamic profile of a front duct ejector in an embodiment of the present invention; Figure 3 This is a schematic diagram of the outer culvert closing flow line of the present invention; Figure 4 Schematic diagram of the distribution of spoiler plates of the three-dimensional front duct ejector in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] An embodiment of a design method of a hinge spoiler type front duct ejector with a pneumatic valve of the present invention is as follows: Figure 1 As shown, including: S1. Determine the geometric parameters of the front duct ejector and the spacing range corresponding to the inner and outer ducts; Specifically, according to the engine design requirements, the geometric parameters of the front duct ejector and the spacing range corresponding to the inner and outer ducts are determined. The geometric parameters include: the maximum inner area S 2max , the minimum connotation area S 2min , the distance I between the lower wall of the internal inlet and the engine rotation axis 0 , the distance H between the inner culvert upper wall and the outer culvert lower wall, and the axial distance L between the inner culvert inlet and the spoiler hinge 2 、Maximum external area S 1max 、Minimum external area S 1min , the axial distance from the outer culvert inlet to the spoiler hinge L 1 And the total axial length L of the front duct ejector.

[0026] Exemplarily, in a specific embodiment, the steps of obtaining the spacing range corresponding to the inner and outer connotations are: obtaining the spacing range of the inner connotation based on the maximum area of ​​the inner connotation, the minimum area of ​​the inner connotation, the distance from the lower wall of the inner connotation to the engine rotation axis, and the spacing from the upper wall of the inner connotation to the lower wall of the outer connotation; obtaining the spacing range of the outer connotation based on the maximum area of ​​the outer connotation, the minimum area of ​​the outer connotation, the distance from the lower wall of the outer connotation to the engine rotation axis, the maximum spacing of the inner connotation, and the spacing from the upper wall of the inner connotation to the lower wall of the outer connotation.

[0027] The steps for obtaining the spacing range of the connotation are: According to the maximum area of ​​the connotation and the distance between the lower wall of the connotation and the engine rotation axis, the maximum spacing of the connotation is obtained; among them, the expression of the minimum spacing of the connotation is:

[0028] According to the minimum area of ​​the connotation, the distance between the lower wall of the connotation and the engine rotation axis, and the distance between the upper wall of the connotation and the lower wall of the outer connotation, the minimum spacing of the connotation is obtained, that is, the expression of the minimum spacing of the connotation is:

[0029] In the formula, is the minimum spacing of connotation; is the maximum spacing of connotation; is the distance between the lower wall and the engine rotation axis; is the maximum area of ​​connotation; is the minimum area of ​​connotation; is the distance from the upper wall of the inner culvert to the lower wall of the outer culvert; According to the minimum spacing and maximum spacing of the connotation, the spacing range of the connotation is obtained. The spacing range of the connotation is ( , ).

[0030] Among them, the steps of obtaining the spacing range of the outer fold are: according to the maximum area of ​​the outer fold, the distance between the lower wall of the outer fold and the engine rotation axis, the maximum spacing of the inner fold, and the spacing from the upper wall of the inner fold to the lower wall of the outer fold, obtain the maximum spacing of the outer fold; according to the minimum area of ​​the outer fold, the maximum spacing of the outer fold, the distance between the lower wall of the outer fold and the engine rotation axis, the maximum spacing of the inner fold, and the spacing from the upper wall of the inner fold to the lower wall of the outer fold; according to the minimum spacing and maximum spacing of the outer fold, obtain the spacing range of the outer fold.

[0031] Among them, the expression of the minimum spacing of the extrinsic is:

[0032] The expression of the maximum spacing of the outer culvert is:

[0033] In the formula, is the minimum spacing of the culvert; is the maximum spacing of the culvert; is the maximum spacing of connotation; is the distance between the lower wall and the engine rotation axis; It is the maximum external area; is the minimum external area; It is the distance from the upper wall of the inner lining to the lower wall of the outer lining.

[0034] Among them, the spacing range of the outer connotation is ( , ).

[0035] S2. Design the initial two-dimensional aerodynamic profile of the front duct ejector; Specifically, based on the principle that the sum of the mixing areas of the inner and outer parts of the front duct ejector at the mixing point remains unchanged, and according to the geometric parameters of the front duct ejector, the initial two-dimensional aerodynamic surface of the front duct ejector is designed.

[0036] The steps of designing the initial two-dimensional aerodynamic profile of the front duct ejector include: making a horizontal line to represent the rotation axis of the aircraft engine, determining the position of the upper wall of the outer duct according to the distance from the lower wall of the inner duct to the rotation axis and the maximum spacing of the inner duct, the spacing from the upper wall of the inner duct to the lower wall of the outer duct, and the maximum spacing of the outer duct; determining the position of the lower wall of the front duct ejector outlet according to the mixing area and the position of the upper wall of the outer duct; determining the position of the lower wall of the outer duct according to the maximum area of ​​the outer duct and the position of the upper wall of the outer duct; determining the uppermost swing position and the lowermost swing position of the spoiler, that is, the swing range of the spoiler, according to the spacing range corresponding to the outer duct and the inner duct; projecting the spoiler onto the lower wall of the outlet according to the preset spoiler radius and the swing range of the spoiler to determine the inner duct The intersection of the lower wall and the lower wall of the front duct ejector outlet; when the spoiler is swung to the uppermost swing position, a perpendicular line is drawn through the root of the spoiler at this moment, and the distance is the maximum spacing of the connotation, and the position of the perpendicular line is the cross-sectional position of the connotation at the root of the spoiler; according to the spacing from the upper wall of the connotation to the lower wall of the outer culvert, the position of the connotation inlet and the maximum area of ​​the connotation, since the connotation inlet section is parallel to the outer culvert inlet section, the inlet section of the connotation and the axial relative position of the connotation inlet section to the outer culvert inlet section can be determined; according to the cross-section of the spoiler root, the connotation inlet section and the axial relative position of the connotation inlet section to the outer culvert inlet section, a curved spline is generated, and the upper and lower walls of the connotation are determined according to the maximum area of ​​the connotation, and the initial two-dimensional aerodynamic surface can be obtained.

[0037] Exemplarily, in a specific embodiment, in combination with the attached Figure 2 Explanation for step 2: Step 21: Make Figure 3 The reference horizontal line PP shown1 To represent the main shaft of the engine, according to the geometric constraints of the engine, no matter where the spoiler rotates, the sum of the areas of the front duct ejector outer and inner parts of the front duct ejector at the mixing point remains unchanged. Therefore, first, according to the mixing area on the reference horizontal line PP 1 Create two horizontal lines PP on the upper side. 1 Parallel lines AE and FF 1 , straight line AE to reference horizontal line PP 1 The distance is I 0 +I 2max +H+I 1max , the length is the total axial length L of the front duct ejector, straight line FF 1 To reference level PP 1 Distance I 0 +I 2max +HI 2min AE represents the upper wall of the front duct ejector, FF 1 Represents the lower wall of the front duct ejector outlet.

[0038] Step 22: Based on the maximum area of ​​the outer cladding , draw a line BM parallel to the line AE, and draw a line BM parallel to the reference horizontal line PP 1 The distance is I 0 +I 2max +H, length is the distance from the outer culvert inlet to the spoiler hinge L 1 , BM represents the lower wall of the culvert, and point M is the hinge position of the spoiler.

[0039] According to the maximum external area and the minimum area of ​​the circumference, respectively draw two parallel lines KK of the straight line AE 1 and JJ 1 , parallel line KK 1 and Parallel Lines JJ 1 Below line AE, parallel to line KK 1 The distance between the line and the straight line AE is I 1min , parallel lines JJ 1 The distance from the line AE is I 1max , parallel line KK 1 The straight line AE represents the minimum spacing of the outer culvert, and the parallel line JJ 1 And straight line AE represents the maximum outer area.

[0040] Select the spoiler radius R, take point M as the circle, and the spoiler with radius R and the parallel line KK with the minimum area of ​​the outer circumference 1 Intersecting at point K, the baffle with a radius of R and the parallel line JJ of the maximum area of ​​the outer lining 1Intersecting at point J, MK is the maximum upward swing position of the spoiler, and MJ is the maximum downward swing position of the spoiler.

[0041] Step 23: According to the spoiler radius and the swing range of the spoiler, project the spoiler on the lower wall of the outlet and make FF through point K. 1 The intersection point of the perpendicular lines is N, and FF is made through point J. 1 The intersection point of the perpendicular line of the line is Q. The point closest to the outer duct inlet between points Q and N is the intersection point of the lower wall of the inner duct and the lower wall of the front duct ejector outlet. In this case, point N is the intersection point.

[0042] Step 24: When the spoiler swings to the uppermost swing position, the outer duct outlet area of ​​the front duct ejector is the smallest and the inner duct outlet area is the largest, so a perpendicular line is drawn through point M to MK with a length of I. 2max Get MS and connect the line segment SN.

[0043] Step 25: Make the spoiler end surface line CD parallel to the outer inlet connecting line AB. The distance between the spoiler end surface line CD and point M is the distance L from the inner inlet to the spoiler hinge. 2 , D distance from engine main axis PP 1 The distance is I 0 , the length of CD is I 2max ,CD stands for Content Import.

[0044] Step 26: Generate a curved center spline with the midpoints of CD and MS, and evenly distribute points on the center line. At these points, make the normal of the center spline with a height of I 2max , the point on the center line of the spline is the midpoint found, and finally the upper part of the points above the normal and the lower part of the points below the normal are fitted into spline curves respectively to form the upper and lower walls of the connotation; that is, the two-dimensional aerodynamic surface of the front duct ejector is composed of AE, BM, CM, DS, SN, NF and MK (MJ), MK indicates that the spoiler is at the uppermost swing position; MJ indicates that the spoiler is at the lowermost position.

[0045] S3, obtaining a target two-dimensional aerodynamic surface; Specifically, it is detected whether there is a local shock wave on the initial two-dimensional aerodynamic surface, and a smooth transition process is performed on the position of the initial two-dimensional aerodynamic surface where the local shock wave exists to obtain a target two-dimensional aerodynamic surface.

[0046] For example, in a specific embodiment, point N in the design process in step 2 is a sharp angle. Through numerical simulation, a local shock wave may appear at point N. In view of the local supersonic speed and shock wave problems that may be caused by point N, appropriate filleting is used to reduce or even eliminate shock wave losses. However, the fillet angle should not be too large and should not exceed point Q, so as to keep the sum of the areas of the outer lining of the front duct ejector and the inner lining of the front duct ejector at the mixing point unchanged, and obtain the target two-dimensional aerodynamic surface after smooth transition processing of the position where the local shock wave exists.

[0047] S4. Determine the final radius of the spoiler and design the spoiler; Specifically, the ejector performance of the target two-dimensional aerodynamic surface under various working conditions is obtained, and the minimum radius of the spoiler is determined according to the ejector performance and ejector performance requirements. The final radius of the spoiler is determined according to the minimum radius and maximum radius of the spoiler, and the spoiler is designed, wherein the working conditions include: the working condition where the spoiler is at the minimum area of ​​the outer culvert, the working condition where the spoiler is at the maximum area of ​​the outer culvert, and the working condition where the spoiler is at the middle area of ​​the outer culvert.

[0048] Exemplarily, in a specific embodiment, the steps of designing a spoiler include: Step 41: Select the working condition, and according to the engine adjustment requirements and the front duct ejector performance requirements, select the position where the spoiler is at the smallest duct area (MK) and the largest duct area (MJ) and the intermediate typical working condition, and determine the internal content of the front duct ejector and the flow state of the duct when the engine is under the corresponding working condition, including but not limited to the pressure and flow at the inlet and outlet, wherein the ejector performance is the total pressure recovery coefficient, wherein the total pressure recovery coefficient of the front duct ejector is obtained according to the internal content of the front duct ejector and the pressure and flow at the inlet and outlet corresponding to the duct.

[0049] Step 42: Reduce the radius of the spoiler and analyze the recirculation area to check the recirculation area formed by the outer culvert at the mixing point. The streamline diagram near the recirculation area is shown in Figure 3 As shown, it is ensured that when the spoiler is swung to the uppermost swing position, the recirculation zone blocks the outer culvert channel, and the outer culvert air flow rate is reduced to 0, thereby achieving the pneumatic valve effect.

[0050] Step 43: Repeat the process of reducing the spoiler radius in step 42. After each reduction, re-simulate the flow field when the spoiler is in the uppermost swing position to find the minimum spoiler radius that meets the index. That is, until the spoiler radius is reduced to a certain value, the outer duct cannot be completely closed or the ejector performance does not meet the performance requirements, the last spoiler radius will be used as the minimum spoiler radius; according to the design requirements of the engine and the front duct ejector, an appropriate margin will be extended as the final spoiler radius , the increase in margin The longest spoiler radius where the spoiler contacts the outer wall With minimum spoiler radius The difference calculation, that is, the final radius of the spoiler The expression is:

[0051] In the formula, is the final radius of the spoiler; is the minimum radius of the spoiler; is the maximum radius of the spoiler, is the proportional coefficient; it is adjusted according to the engine inner and outer duct radius and the performance of the front duct ejector under multiple working conditions.

[0052] S5, obtaining the three-dimensional structure of the front duct ejector; The three-dimensional structure of the ejector is obtained based on the target two-dimensional aerodynamic surface and the spoiler of the final radius, that is, the target two-dimensional aerodynamic surface is rotated around the main axis of the engine to generate a three-dimensional annular section; the spoiler of the final radius is connected to the front end of the intersection of the inner and outer ends through a hinge to obtain the three-dimensional structure of the ejector.

[0053] Exemplarily, in a specific embodiment, the steps of designing the three-dimensional structure of the front duct ejector are: Step 51: For the target two-dimensional aerodynamic profile of the ducted ejector designed in step S3, the upper and lower walls of the inner and outer ducts are of fixed geometry, and the center distance between the inner and outer ducts, and the relative positions of the inlet and outlet have been determined through two-dimensional design, such as Figure 3 As shown. Just revolve around the engine main shaft ( Figure 3 Medium PP 1 The three-dimensional model configuration can be completed by rotating the inner and outer content to form a coaxial three-dimensional annular section.

[0054] Step 52: For the adjustable hinge spoiler structure, a three-dimensional curved surface structure is generated by rotating around the main axis of the engine. Multiple spoilers are spliced ​​to form the curved surface structure to achieve the adjustability of the spoiler, wherein each spoiler is unfolded into a fan ring structure. During the adjustment process, the airtightness is maintained by overlapping the edge parts. The schematic diagram of the axial projection distribution of the spoiler is shown in FIG. Figure 4 As shown, the curvature of the spoiler is consistent with the curvature of the lower wall of the front duct ejector outer culvert.

[0055] Step 53: Each spoiler is connected to the duct wall through a hinge. The hinge is designed to be located at the contact point between the spoiler and the duct wall. The spoilers are evenly distributed in the front duct ejector with equal arc lengths, keeping the radial length of a single spoiler unchanged and increasing the circumferential length of the spoiler. At the same time, two adjacent spoilers are staggered front and back, and the edge areas overlap, so that the arc surface structure spliced ​​within the spoiler adjustment range can maintain good air tightness.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A design method for a hinge spoiler type front duct ejector with a pneumatic valve, characterized in that: include: According to the engine design requirements, determine the geometric parameters of the front duct ejector and the corresponding spacing range of the inner duct and the outer duct. The geometric parameters include: the maximum area of ​​the inner duct, the minimum area of ​​the inner duct, the distance from the lower wall of the inner duct inlet to the engine rotation axis, the spacing from the upper wall of the inner duct to the lower wall of the outer duct, the axial distance from the inner duct inlet to the spoiler hinge, the maximum area of ​​the outer duct, the minimum area of ​​the outer duct, the axial distance from the outer duct inlet to the spoiler hinge, and the total axial length of the front duct ejector; Based on the principle that the sum of the mixing areas of the inner and outer parts of the front duct ejector at the mixing point remains unchanged, and according to the geometric parameters of the front duct ejector, the initial two-dimensional aerodynamic profile of the front duct ejector is designed; Detecting whether there is a local shock wave on the initial two-dimensional aerodynamic profile, and performing smooth transition processing on the position of the initial two-dimensional aerodynamic profile where the local shock wave exists to obtain a target two-dimensional aerodynamic profile; Obtain the ejector performance of the target two-dimensional aerodynamic profile under various working conditions, determine the minimum radius of the spoiler according to the ejector performance and ejector performance requirements, determine the final radius of the spoiler according to the minimum radius and maximum radius of the spoiler, and design the spoiler, wherein the working conditions include: the working condition of the spoiler at the minimum area of ​​the outer culvert, the working condition of the spoiler at the maximum area of ​​the outer culvert, and the working condition of the spoiler at the middle area of ​​the outer culvert; The three-dimensional structure of the front duct ejector is obtained based on the target two-dimensional aerodynamic profile and the spoiler with the final radius.

2. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 1 is characterized in that: Based on the principle that the sum of the mixing areas of the inner and outer parts of the front duct ejector at the mixing point remains unchanged, and according to the geometric parameters of the front duct ejector, the steps for designing the initial two-dimensional aerodynamic profile of the front duct ejector are as follows: Draw a horizontal line to represent the rotation axis of the aircraft engine, determine the position of the upper wall of the outer duct according to the distance between the lower wall of the inner duct and the rotation axis and the maximum spacing of the inner duct, the spacing between the upper wall of the inner duct and the lower wall of the outer duct, and the maximum spacing of the outer duct, determine the position of the lower wall of the front duct ejector outlet according to the mixing area and the position of the upper wall of the outer duct, and determine the position of the lower wall of the outer duct according to the maximum area of ​​the outer duct and the position of the upper wall of the outer duct; According to the spacing range corresponding to the outer connotation and the inner connotation, the uppermost swing position and the lowermost swing position of the spoiler, that is, the swing range of the spoiler, are determined; According to the preset spoiler radius and the swing range of the spoiler, the spoiler is projected onto the lower wall surface of the outlet to determine the intersection point between the lower wall surface of the inner duct and the lower wall surface of the outlet of the front duct ejector; When the spoiler is swung to the uppermost swing position, a vertical line is drawn through the root of the spoiler at this moment, and the distance is the maximum spacing. The position of the vertical line is the cross-sectional position of the root of the spoiler. According to the distance from the upper wall of the inner culvert to the lower wall of the outer culvert, the position of the inner culvert inlet and the maximum area of ​​the inner culvert, since the inner culvert inlet section is parallel to the outer culvert inlet section, the inner culvert inlet section and the axial relative position of the inner culvert inlet section to the outer culvert inlet section can be determined; The curved spline is generated according to the spoiler root section, the inner inlet section and the axial relative position of the inner inlet section to the outer inlet section, and the upper and lower walls of the inner section are determined according to the maximum area of ​​the inner section to obtain the initial two-dimensional aerodynamic surface.

3. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 2, characterized in that: The steps to obtain the spacing range corresponding to the connotation and the connotation are: Obtain the spacing range of the connotation according to the maximum connotation area, the minimum connotation area, the distance between the lower wall of the connotation and the engine rotation axis, and the spacing between the upper wall of the connotation and the lower wall of the outer connotation; The spacing range of the culvert is obtained according to the maximum area of ​​the culvert, the minimum area of ​​the culvert, the distance between the lower wall of the culvert and the engine rotation axis, the maximum spacing of the inner culvert, and the spacing from the upper wall of the inner culvert to the lower wall of the culvert.

4. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 3 is characterized in that: The steps to obtain the spacing range of the connotation are: According to the maximum area of ​​the connotation and the distance between the lower wall of the connotation and the engine rotation axis, the maximum spacing of the connotation is obtained; The minimum spacing of the inner lining is obtained according to the minimum area of ​​the inner lining, the distance between the lower wall of the inner lining and the rotation axis of the engine, and the spacing between the upper wall of the inner lining and the lower wall of the outer lining; The connotation spacing range is obtained according to the connotation minimum spacing and maximum spacing.

5. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 3, characterized in that: The steps to obtain the extrinsic spacing range are: The maximum spacing of the culvert is obtained according to the maximum area of ​​the culvert, the distance between the lower wall of the culvert and the engine rotation axis, the maximum spacing of the inner culvert, and the spacing from the upper wall of the inner culvert to the lower wall of the culvert; Obtain the minimum spacing of the culvert according to the minimum area of ​​the culvert, the maximum spacing of the culvert, the distance between the lower wall of the culvert and the engine rotation axis, the maximum spacing of the inner culvert, and the spacing from the upper wall of the inner culvert to the lower wall of the culvert; The spacing range of the culvert is obtained according to the minimum spacing and the maximum spacing of the culvert.

6. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 4, characterized in that: The steps to obtain the minimum and maximum spacing of the connotation are: The expression of the minimum spacing is: The expression of the maximum spacing is: In the formula, is the minimum spacing of connotation; is the maximum spacing of connotation; is the distance between the lower wall and the engine rotation axis; is the maximum area of ​​connotation; is the minimum area of ​​connotation; It is the distance from the upper wall of the inner lining to the lower wall of the outer lining.

7. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 5, characterized in that: The steps to obtain the minimum and maximum spacing of the culvert are: The expression of the minimum spacing of the culvert is: The expression of the maximum spacing of the outer culvert is: In the formula, is the minimum spacing of the culvert; is the maximum spacing of the culvert; is the maximum spacing of connotation; is the distance between the lower wall and the engine rotation axis; It is the maximum external area; is the minimum external area; It is the distance from the upper wall of the inner lining to the lower wall of the outer lining.

8. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 1, characterized in that: The steps to determine the minimum radius of the spoiler are: The ejector performance is the total pressure recovery coefficient, wherein the total pressure recovery coefficient of the front duct ejector is obtained according to the pressure and flow at the inlet and outlet corresponding to the inner and outer ducts of the front duct ejector; The spoiler radius is reduced multiple times and the flow field is re-simulated until the spoiler radius is reduced to a certain value and the outer duct cannot be completely closed or the ejector performance does not meet the performance requirements. The last spoiler radius is used as the minimum spoiler radius.

9. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 1, characterized in that: The steps to determine the final radius of the spoiler according to the minimum radius and maximum radius of the spoiler are: In the formula, is the final radius of the spoiler; is the proportionality coefficient; is the minimum radius of the spoiler; is the maximum radius of the spoiler.

10. The design method of a hinge spoiler type front duct ejector with a pneumatic valve according to claim 1, characterized in that: The steps for obtaining the three-dimensional aerodynamic profile of the ejector based on the target two-dimensional aerodynamic profile and the spoiler with the final radius are as follows: The target two-dimensional aerodynamic surface is rotated around the main axis of the engine to generate a three-dimensional annular section; the spoiler with the final radius is connected to the front end of the intersection of the inner duct and the outer duct through a hinge to obtain the three-dimensional structure of the front duct ejector.

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