Two-dimensional aerodynamic profile design method for counter-rotating propeller volutes

Abstract

The application provides a two-dimensional aerodynamic profile design method of a reverse thrust volute, the reverse thrust volute having a two-dimensional inner side aerodynamic profile and a two-dimensional outer side aerodynamic profile. The method comprises: obtaining a reverse thrust airflow outlet width, a reverse thrust airflow radial velocity, a reverse thrust airflow total pressure, a reverse thrust airflow axial velocity and a height when the reverse thrust airflow is not turbulent; calculating three direction parameters based on the reverse thrust airflow radial velocity and the reverse thrust airflow axial velocity; determining a first feature point based on a first direction parameter, the reverse thrust airflow outlet width and the height when the reverse thrust airflow is not turbulent; determining a second feature point, a third feature point and a fourth feature point based on the reverse thrust airflow total pressure, the first feature point and the three direction parameters; determining the two-dimensional inner side aerodynamic profile according to a fourth-order Bezier curve based on the four feature points; and determining the two-dimensional outer side aerodynamic profile based on the two-dimensional inner side aerodynamic profile and the reverse thrust airflow outlet width. The method can construct the aerodynamic profile of the reverse thrust volute with good aerodynamic performance in a short time.

Description

Technical Field

[0001] This application mainly relates to the field of engine testing technology, and in particular to a two-dimensional aerodynamic profile design method for a thrust reverser volute. Background Technology

[0002] In recent years, with the accelerated development of domestically produced high-bypass turbofan engines, engine testing tasks have been increasing. Among these, engine thrust reverse testing is crucial for verifying whether the engine's thrust reverse function meets airworthiness standards and is one of the important tests for engine model performance verification. When an engine undergoes thrust reverse testing on an indoor test bench, the thrust reverse airflow may be re-intaken into the engine under test because its exit direction is opposite to the mainstream. This can lead to additional engine vibration or overheating, which is detrimental to the normal conduct of the thrust reverse test and poses safety hazards. Therefore, it is necessary to design a thrust reverser vortex to guide the thrust reverse airflow to the rear of the engine for discharge.

[0003] A thrust reverser is a device used in thrust reverser testing to prevent the engine from re-inhaling the reversed thrust flow. The aerodynamic profile of the thrust reverser should meet three requirements: minimal impact on the engine's reversed thrust outlet back pressure, low leakage, and smooth exhaust. Therefore, extensive model verification and optimization are required during aerodynamic profile design. Furthermore, due to the axisymmetric nature of the thrust reverser within a certain circumferential range, it is essential to construct a two-dimensional aerodynamic profile design method for the thrust reverser.

[0004] According to the requirements of the reverse thrust test, the design method of the two-dimensional aerodynamic profile of the reverse thrust volute should solve the following problems: 1. Constructing an aerodynamic profile with relatively good aerodynamic performance in a short time is beneficial for selecting the best verification results later; 2. The aerodynamic profile of the thrust reverser casing obtained in the design needs to be quantitatively characterized, which is beneficial for aerodynamic design optimization; 3. The design method should meet the profile design requirements under different airflow angles; 4. The design method should be applicable to different test benches. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a two-dimensional aerodynamic profile design method for a thrust volute, which can construct an aerodynamic profile with good aerodynamic performance in a short time. The aerodynamic profile is quantitatively characterized, meets the profile design requirements under different airflow angles, and is applicable to different test benches.

[0006] To address the aforementioned technical problems, this application provides a two-dimensional aerodynamic profile design method for a thrust reverser volute. The thrust reverser volute has a two-dimensional inner aerodynamic profile and a two-dimensional outer aerodynamic profile. The method includes: obtaining the thrust reverser airflow outlet width, thrust reverser airflow radial velocity, thrust reverser airflow total pressure, thrust reverser airflow axial velocity, and thrust reverser airflow height when turbulent; calculating a first direction parameter, a second direction parameter, and a third direction parameter based on the thrust reverser airflow radial velocity and the thrust reverser airflow axial velocity; determining a first feature point based on the first direction parameter, the thrust reverser airflow outlet width, and the thrust reverser airflow height when turbulent; determining a second feature point, a third feature point, and a fourth feature point based on the thrust reverser airflow total pressure, the first feature point, the first direction parameter, the second direction parameter, and the third direction parameter; determining the two-dimensional inner aerodynamic profile based on the first feature point, the second feature point, the third feature point, and the fourth feature point, according to a fourth-order Bézier curve; and determining the two-dimensional outer aerodynamic profile based on the two-dimensional inner aerodynamic profile and the thrust reverser airflow outlet width.

[0007] In one embodiment of this application, the first direction parameter is calculated in the following manner:

[0008] in, The first direction parameter, The radial velocity of the reverse airflow. The axial velocity of the reverse airflow; The second direction parameter is calculated in the following way:

[0009] in, The first direction parameter, Here, A is the second direction parameter, and A is the preset first coefficient. The third-party parameter is calculated in the following way:

[0010] in, This is the second direction parameter. Let B be the third-party directional parameter, and let B be the preset second coefficient.

[0011] In one embodiment of this application, the first feature point is calculated in the following manner:

[0012] in, Let x be the x-coordinate of the first feature point. Let W be the ordinate of the first feature point, W be the width of the reverse airflow outlet, C be a preset third coefficient, and D be a preset fourth coefficient. Here, H is the first directional parameter, and H is the height of the reverse airflow when it is undisturbed. The second feature point is calculated in the following way:

[0013] in, The x-coordinate of the second feature point is... The ordinate of the second feature point is... Let x be the x-coordinate of the first feature point. Let be the ordinate of the first feature point, and E be a preset fifth coefficient. The first direction parameter, The total pressure of the reverse airflow; The third feature point is calculated in the following way:

[0014] in, The x-coordinate of the third feature point is... The ordinate of the third feature point is... The x-coordinate of the second feature point is... Let be the ordinate of the second feature point, and F be a preset sixth coefficient. This is the second direction parameter. The total pressure of the reverse airflow; The fourth feature point is calculated in the following way:

[0015] in, The x-coordinate of the fourth feature point is... The ordinate of the fourth feature point is... The x-coordinate of the third feature point is... Let G be the ordinate of the third feature point, and G be a preset seventh coefficient. For the third-party parameter, The total pressure of the reverse airflow.

[0016] In one embodiment of this application, the method further includes: obtaining the friction distance corresponding to the maximum area of ​​the cross-section of the thrust reverser volute; wherein the step of determining the two-dimensional outer aerodynamic profile based on the two-dimensional inner aerodynamic profile and the thrust reverser airflow outlet width includes: determining the inlet diameter and outlet diameter of the thrust reverser volute based on the thrust reverser airflow outlet width; constructing a flow area variation curve of the two-dimensional outer aerodynamic profile based on the inlet diameter and the outlet diameter according to a bicubic curve, wherein the friction distance corresponding to the maximum area of ​​the cross-section of the thrust reverser volute is the extreme value of the bicubic curve; and determining the two-dimensional outer aerodynamic profile based on the flow area variation curve and the two-dimensional inner aerodynamic profile.

[0017] In one embodiment of this application, the step of determining the two-dimensional outer aerodynamic profile based on the two-dimensional inner aerodynamic profile and the thrust reverser outlet width includes: determining the inlet diameter and outlet diameter of the thrust reverser volute based on the thrust reverser outlet width; constructing a flow area variation curve of the two-dimensional outer aerodynamic profile based on the inlet diameter and the outlet diameter, according to the Vysinski curve, quintic curve, or shift-axis Vysinski curve; and determining the two-dimensional outer aerodynamic profile based on the flow area variation curve and the two-dimensional inner aerodynamic profile.

[0018] In one embodiment of this application, the method further includes: verifying whether the thrust reverser housing having the two-dimensional inner aerodynamic profile and the two-dimensional outer aerodynamic profile meets the thrust reverser test requirements; and if the thrust reverser test requirements are not met, re-determining the first feature point, the second feature point, the third feature point, and the fourth feature point using a normal distribution value method.

[0019] In one embodiment of this application, the method further includes: if the backtesting requirements are not met, resetting the standard deviation of the normal distribution value taking method.

[0020] In one embodiment of this application, the method further includes: obtaining the space limitation parameters of the test stand, and ensuring that the size of the thrust reverser housing is not greater than the space limitation parameters of the test stand.

[0021] In one embodiment of this application, the thrust reverser housing is a C-shaped thrust reverser housing.

[0022] Compared with existing technologies, the two-dimensional aerodynamic profile design method for the thrust reverser housing in this application can generate a second-order continuous and smooth aerodynamic profile through fourth-order Bézier curves, leaving a larger margin for subsequent structural design. By using the positions of four feature points and the width of the thrust reverser airflow outlet to quantify the two-dimensional aerodynamic profile of the thrust reverser housing, the aerodynamic profile can be quantitatively controlled or optimized. The two-dimensional aerodynamic profile design method for the thrust reverser housing in this application can construct aerodynamic profiles with good aerodynamic performance in a short time. The aerodynamic profile is quantitatively characterized, meets the profile design requirements under different airflow angles, and is applicable to different test stands. Attached Figure Description

[0023] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings: Figure 1 This is a flowchart illustrating a two-dimensional aerodynamic profile design method for a reverse-propeller volute according to an embodiment of this application.

[0024] Figure 2 This is a schematic diagram of the aerodynamic profile of the thrust reverser housing in a radial section, according to an embodiment of this application.

[0025] Figure 3 This is a schematic diagram illustrating the determination of four feature points using a normal distribution method according to an embodiment of this application.

[0026] Figure 4 This is a schematic diagram illustrating the generation process of the two-dimensional outer aerodynamic profile of the reverse-propeller casing according to an embodiment of this application. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual applications without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of these specific embodiments.

[0028] For example, a first feature subsequently described in the specification being formed above or on a second feature can include embodiments where the first and second features are formed in a direct connection, or embodiments where an additional feature is formed between the first and second features, so that the first and second features are not directly connected. Additionally, reference numerals and / or letters may be repeated in different examples in these disclosures. This repetition is for brevity and clarity and does not in itself indicate a relationship between the various embodiments and / or structures to be discussed. Furthermore, when a first element is described in a manner connected or combined with a second element, the description includes embodiments where the first and second elements are directly connected or combined with each other, as well as embodiments where one or more other intervening elements are incorporated to indirectly connect or combine the first and second elements with each other.

[0029] As illustrated in this invention, unless the context clearly indicates otherwise, the words "a," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0030] For ease of description, spatial relation terms such as “below,” “below,” “lower than,” “below,” “above,” “upper,” etc., may be used herein to describe the relationship of an element or feature shown in the accompanying drawings to other elements or features. It will be understood that these spatial relation terms are intended to include orientations of the device in use or operation other than those depicted in the accompanying drawings. For example, if the device in the accompanying drawings is flipped, the orientation of an element described as “below,” “below,” or “below” to other elements or features will change to “above” said other elements or features. Thus, the exemplary terms “below” and “below” can encompass both upward and downward directions. The device may also have other orientations (rotated 90 degrees or in other orientations), and therefore the spatial relation descriptors used herein should be interpreted accordingly. Furthermore, it will be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between.

[0031] It should be noted that these and subsequent accompanying drawings are merely illustrative and are not drawn to scale, nor should they be construed as limiting the scope of protection of the present invention. Furthermore, variations in different embodiments can be appropriately combined.

[0032] This application provides a two-dimensional aerodynamic profile design method for a thrust reverser shroud. The thrust reverser shroud, a device required during thrust reverser testing to prevent engine re-intake of thrust reverse airflow, has a two-dimensional inner aerodynamic profile and a two-dimensional outer aerodynamic profile. In one embodiment of this application, the thrust reverser shroud can be a C-shaped thrust reverser shroud.

[0033] Figure 1 This is a flowchart illustrating a two-dimensional aerodynamic profile design method for a reverse-propeller volute according to an embodiment of this application. Figure 2 This is a schematic diagram of the aerodynamic profile of the thrust reverser housing in a radial section, according to an embodiment of this application. Figure 1 As shown, the two-dimensional aerodynamic profile design method for the thrust reverser housing in this embodiment includes the following steps 101-106: Step 101: Obtain the thrust reverser outlet width, thrust reverser radial velocity, thrust reverser total pressure, thrust reverser axial velocity, and thrust reverser height when turbulent. The thrust reverser height when turbulent can be obtained at the aerodynamic inlet based on simulation or experimental results. Figure 2 For example, the width of the airflow outlet is calculated as the distance from point A1 to point A2.

[0034] Step 102: Calculate the first direction parameter, the second direction parameter, and the third direction parameter based on the radial velocity and axial velocity of the thrust reverser airflow. In this embodiment, the thrust reverser volute can be quantitatively characterized by four feature points. Figure 2 For example, in this embodiment, the four feature points used to quantify and characterize the aerodynamic profile are as follows: Figure 2 In the diagram, P0, P1, P2, and P3 are used, where P0 is the first feature point, P1 is the second feature point, P2 is the third feature point, and P3 is the fourth feature point. The first direction parameter can be used to calculate the x-coordinate of the first feature point P0 and represent the direction from the first feature point P0 to the second feature point P1. The second direction parameter can be used to represent the direction from the second feature point P1 to the third feature point P2. The third direction parameter can be used to represent the direction from the third feature point P2 to the fourth feature point P3.

[0035] Step 103: Determine the first feature point based on the first directional parameters, the width of the reverse airflow outlet, and the height of the reverse airflow when it is undisturbed. Figure 2 For example, let the origin of the coordinate axis be A2. Figure 2 The X-axis is parallel to the engine axis, and the Y-axis is perpendicular to the engine axis. In one example, the Y-coordinate of the first feature point P0 can be the height at which the reverse airflow is undisturbed.

[0036] Step 104: Determine the second, third, and fourth feature points based on the total reverse airflow pressure, the first feature point, the first directional parameter, the second directional parameter, and the third directional parameter.

[0037] Step 105: Based on the first, second, third, and fourth feature points, determine the two-dimensional inner aerodynamic profile according to the fourth-order Bézier curve. The obtained two-dimensional inner aerodynamic profile can be as follows: Figure 2 The inner curve is shown. The two-dimensional inner aerodynamic profile of the reverse-thrust volute is determined based on four feature points, allowing the two-dimensional inner aerodynamic profile to be quantitatively controlled or optimized.

[0038] Step 106: Determining the two-dimensional inner aerodynamic profile and the thrust reverser outlet width. Based on the already obtained two-dimensional inner aerodynamic profile of the thrust reverser, the two-dimensional outer aerodynamic profile of the thrust reverser is determined according to the thrust reverser outlet width, so that the two-dimensional outer aerodynamic profile can also be quantitatively controlled or optimized.

[0039] In one embodiment of this application, the method may further include the step of obtaining the spatial constraint parameters of the test stand and ensuring that the size of the thrust reverser housing is not greater than the spatial constraint parameters of the test stand. By limiting the size of the thrust reverser housing to within the spatial range of the test stand, it can be ensured that the designed thrust reverser housing can be used on the test stand to be tested. Furthermore, by changing the restriction on the range of characteristic point values ​​of the thrust reverser housing, aerodynamic profiles of the thrust reverser housing suitable for different test stands can be obtained or improved.

[0040] In summary, the two-dimensional aerodynamic profile design method for the thrust reverser housing in this embodiment can generate a second-order continuous and smooth aerodynamic profile through fourth-order Bézier curves, providing greater margin for subsequent structural design. By using the positions of four feature points and the width of the thrust reverser airflow outlet to quantify the two-dimensional characterization of the aerodynamic profile of the thrust reverser housing, the aerodynamic profile can be quantitatively controlled or optimized. Furthermore, it can construct aerodynamic profiles with good aerodynamic performance in a short time. The aerodynamic profile is quantitatively characterized, meets the profile design requirements under different airflow angles, and is applicable to different test stands.

[0041] In another embodiment of this application, the two-dimensional aerodynamic profile design method for the reverse-propeller volute includes the following steps: Obtain the thrust reverser outlet width, radial velocity, total pressure, axial velocity, and undisturbed height of the thrust reverser. The undisturbed height can be obtained at the aerodynamic inlet based on simulation or experimental results. Figure 2 For example, the width of the airflow outlet is calculated as the distance from A1 to A2.

[0042] The first, second, and third directional parameters are calculated based on the radial and axial velocities of the thrust reverser airflow. In this embodiment, the thrust reverser volute can be quantitatively characterized by four feature points. Figure 2For example, in this embodiment, the four feature points used to quantify and characterize the aerodynamic profile are as follows: Figure 2 In the diagram, P0, P1, P2, and P3 represent four feature points: P0 is the first feature point, P1 is the second feature point, P2 is the third feature point, and P3 is the fourth feature point. The first direction parameter can be a parameter used to calculate the x-coordinate of the first feature point P0 and a parameter representing the direction from the first feature point P0 to the second feature point P1. The second direction parameter can be a parameter representing the direction from the second feature point P1 to the third feature point P2. The third direction parameter can be a parameter representing the direction from the third feature point P2 to the fourth feature point P3.

[0043] The first direction parameter is calculated in the following way:

[0044] in, For the first direction parameter, To reverse the radial velocity of the airflow, This is to calculate the axial velocity of the reverse airflow.

[0045] The second direction parameter is calculated in the following way:

[0046] in, For the first direction parameter, Here, A is the second direction parameter, and A is the preset first coefficient. In one example, the value of A can be 1.585.

[0047] The third direction parameter is calculated in the following way:

[0048] in, For the second direction parameter, Here, B is a third-party parameter, and B is a preset second coefficient. In one example, the value of B can be 1.229.

[0049] The first feature point is determined based on the first directional parameters, the width of the reverse airflow outlet, and the height of the reverse airflow when it is undisturbed. Figure 2 For example, the origin of the coordinate axis is A2. Figure 2 The X-axis is parallel to the engine axis, and the Y-axis is perpendicular to the engine axis. The first feature point is calculated as follows:

[0050] in, The x-coordinate of the first feature point is... Let W be the ordinate of the first feature point, W be the width of the reverse airflow outlet, C be the preset third coefficient, and D be the preset fourth coefficient. Here, C is the first directional parameter, and H is the height at which the reverse airflow is undisturbed. In one example, C can be 0.523 and D can be 151.75.

[0051] The second, third, and fourth feature points are determined based on the total pressure of the reverse airflow, the first feature point, the first directional parameter, the second directional parameter, and the third directional parameter.

[0052] The second feature point is calculated in the following way:

[0053] in, The x-coordinate of the second feature point. The ordinate of the second feature point is... The x-coordinate of the first feature point is... Let be the ordinate of the first feature point, and E be the preset fifth coefficient. For the first direction parameter, This is used to calculate the total pressure of the reverse airflow. In one example, the value of E can be 0.0198.

[0054] The third feature point is calculated in the following way:

[0055] in, The x-coordinate of the third feature point The ordinate of the third feature point is... The x-coordinate of the second feature point. Let be the ordinate of the second feature point, and F be the preset sixth coefficient. For the second direction parameter, This is used to calculate the total pressure of the reverse airflow. In one example, the value of F can be 0.0068.

[0056] The fourth feature point is calculated in the following way:

[0057] in, The x-coordinate of the fourth feature point. The ordinate of the fourth feature point is... The x-coordinate of the third feature point Let G be the ordinate of the third feature point, and G be the preset seventh coefficient. For third-party parameters, This is used to calculate the total pressure of the reverse airflow. In one example, the value of G can be 0.041.

[0058] The first to seventh coefficients AG mentioned above can all be set according to actual needs. This application does not limit the values ​​of the first to seventh coefficients AG.

[0059] Based on the first, second, third, and fourth feature points, the two-dimensional inner aerodynamic profile is determined according to the fourth-order Bézier curve. Using these four feature points to determine the two-dimensional inner aerodynamic profile of the thrust reverser casing allows for quantitative control or optimization of the two-dimensional inner aerodynamic profile.

[0060] The two-dimensional outer aerodynamic profile is determined based on the two-dimensional inner aerodynamic profile and the reverse airflow outlet width.

[0061] In one embodiment of this application, the method may further include the step of obtaining the friction distance corresponding to the maximum area of ​​the thrust reverser volute cross-section. The step of determining the two-dimensional outer aerodynamic profile based on the two-dimensional inner aerodynamic profile and the thrust reverser airflow outlet width can be performed using a bicubic curve, specifically including the following steps: determining the inlet diameter and outlet diameter of the thrust reverser volute based on the thrust reverser airflow outlet width. In one embodiment of this application, the inlet diameter can be the product of the thrust reverser airflow outlet width and a preset inlet diameter coefficient, and the outlet diameter can be the product of the thrust reverser airflow outlet width and a preset outlet diameter coefficient. In one example, the inlet diameter coefficient can be 2.046, and the outlet diameter coefficient can be 0.33724. Both the inlet diameter coefficient and the outlet diameter coefficient can be set according to actual needs, and this application does not limit this. Based on the inlet diameter and outlet diameter, a flow area variation curve of the two-dimensional outer aerodynamic profile is constructed according to the bicubic curve, wherein the friction distance corresponding to the maximum area of ​​the thrust reverser volute cross-section is the extreme value of the bicubic curve. Then, based on the inner and outer profile diameters corresponding to each distance along the flow area change curve, the two-dimensional outer aerodynamic profile is determined by extending outward from the inner aerodynamic profile. Figure 4 This is a schematic diagram illustrating the generation process of the two-dimensional outer aerodynamic profile of the reverse-propeller casing according to an embodiment of this application.

[0062] By using a bicubic curve to determine the two-dimensional outer aerodynamic profile, and taking the distance along the path corresponding to the maximum area of ​​the reverse-engineered volute cross section as the extreme value of the bicubic curve, a better two-dimensional outer aerodynamic profile can be obtained.

[0063] In another embodiment of this application, the step of determining the two-dimensional outer aerodynamic profile based on the two-dimensional inner aerodynamic profile and the reverse thrust outlet width can be performed using a Wysinski curve, a quintic curve, or a shift-axis Vickers curve. Specifically, it includes the following steps: determining the inlet diameter and outlet diameter of the reverse thrust volute based on the reverse thrust outlet width. In one embodiment of this application, the inlet diameter can be the product of the reverse thrust outlet width and a preset inlet diameter coefficient, and the outlet diameter can be the product of the reverse thrust outlet width and a preset outlet diameter coefficient. In one example, the inlet diameter coefficient can be 2.046, and the outlet diameter coefficient can be 0.33724. Both the inlet diameter coefficient and the outlet diameter coefficient can be set according to actual needs, and this application does not limit this. Based on the inlet diameter and outlet diameter, a flow area variation curve for the two-dimensional outer aerodynamic profile is constructed according to the Wysinski curve, quintic curve, or shift-axis Vickers curve. Then, based on the inner and outer profile diameters corresponding to each distance along the flow area variation curve, the two-dimensional outer aerodynamic profile is determined by extending outward from the inner aerodynamic profile.

[0064] Based on the two-dimensional inner aerodynamic profile of the thrust reverser housing, the two-dimensional outer aerodynamic profile of the thrust reverser housing is determined according to the width of the thrust reverser airflow outlet, so that the two-dimensional outer aerodynamic profile can also be quantitatively controlled or optimized.

[0065] Having obtained the two-dimensional inner and outer aerodynamic profiles of the thrust reverser volute, the two-dimensional aerodynamic profile design of the thrust reverser volute is complete. The designed thrust reverser volute still needs to be tested to verify whether its aerodynamic performance meets the requirements. If it does not meet the requirements, it is necessary to continue iterative optimization and adjustment of the thrust reverser volute.

[0066] In one embodiment of this application, after initially determining the two-dimensional inner and outer aerodynamic profiles of the thrust reverser housing, the method may further include the following steps to optimize and adjust the thrust reverser housing: verifying whether the thrust reverser housing with the two-dimensional inner and outer aerodynamic profiles meets the thrust reverser test requirements. If it does not meet the thrust reverser test requirements, the first, second, third, and fourth feature points are re-determined using a normal distribution (also known as a Gaussian distribution) method. The above steps can be repeated as needed until the thrust reverser housing meets the thrust reverser test requirements.

[0067] Figure 3This is a schematic diagram illustrating the determination of four feature points using a normal distribution method according to an embodiment of this application. The horizontal line segment containing the first feature point P0 represents the normal distribution range of point P0. Starting from point P0, moving upwards along the reverse airflow direction, the coordinates of point P1 are obtained; the line segment containing the second feature point P1 represents the normal distribution range of point P1. A fan-shaped area extending from point P1 to the Y-direction boundary is drawn; this fan-shaped area represents the normal distribution range of the third feature point P2, and the coordinates of point P2 are obtained. A rectangular area extending from point P1 to the X-direction boundary is drawn; this rectangular area represents the normal distribution range of the fourth feature point P3, and the coordinates of point P3 are obtained. The coordinates of P0-P3 can be calculated using the aforementioned method, and will not be repeated here. By changing the relative positions of the feature points, the shape of the aerodynamic profile can be controlled and made suitable for different reverse airflow angles, resulting in a reverse airflow volute aerodynamic profile suitable for multiple angles.

[0068] If the requirements for the reverse engineering test are not met, when redetermining the first, second, third, and fourth feature points using the normal distribution method, the standard deviation of the normal distribution method can be reset. The range of normal distribution values ​​for the four feature points P0-P3 is controlled by the standard deviation of the normal distribution method. By adjusting the standard deviation of the normal distribution, the position of the feature points can be controlled, thereby changing the shape of the inner surface.

[0069] In one embodiment of this application, the method may further include the step of obtaining the space constraint parameters of the test stand and ensuring that the size of the reverse thrust volute is not greater than the space constraint parameters of the test stand. Figure 3 As shown, the outermost box represents the space constraints of the test bench. and These are the spatial constraint parameters on the X-axis and the Y-axis, respectively.

[0070] By limiting the dimensions of the thrust reverser housing to the space of the test stand, it can be ensured that the designed thrust reverser housing can be used on the test stand to be tested. Furthermore, by changing the restrictions on the range of characteristic point values ​​of the thrust reverser housing, aerodynamic profiles of the thrust reverser housing suitable for different test stands can be obtained or improved.

[0071] In summary, the two-dimensional aerodynamic profile design method for the reverse thrust volute of this application, based on the spatial constraints of the test bench and combined with the normal distribution method, obtains four radially distributed feature points, and then generates the inner profile using fourth-order Bézier curves. During the iterative optimization of the inner profile, the position of the feature points can be controlled by adjusting the standard deviation of the normal distribution, thereby changing the shape of the inner profile. By controlling the width of the volute inlet and outlet, the flow area law of the aerodynamic profile is controlled, and the area change trend of the aerodynamic profile is finally obtained, constructing and generating the outer profile, ultimately resulting in the complete aerodynamic shape of the reverse thrust volute.

[0072] The two-dimensional aerodynamic profile design method for the inverse volute of this application can obtain multiple sets of aerodynamic profiles with relatively good performance in a short time. The aerodynamic performance can be verified by simulation or scaled-down test and the best one can be selected. Finally, the optimized aerodynamic shape can be output, which is beneficial for the optimization and adjustment of the aerodynamic shape in the iterative process between the structural design and the design.

[0073] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A two-dimensional aerodynamic profile design method for a thrust reverser volute, the thrust reverser volute having a two-dimensional inner aerodynamic profile and a two-dimensional outer aerodynamic profile, the method comprising: Obtain the thrust reverser outlet width, thrust reverser radial velocity, thrust reverser total pressure, thrust reverser axial velocity, and thrust reverser height when turbulent; Calculate the first direction parameter, the second direction parameter, and the third direction parameter based on the radial velocity and the axial velocity of the reverse thrust airflow; The first feature point is determined based on the first directional parameter, the width of the reverse airflow outlet, and the height of the reverse airflow when it is undisturbed. The second, third, and fourth feature points are determined based on the total pressure of the reverse airflow, the first feature point, the first directional parameter, the second directional parameter, and the third directional parameter. Based on the first feature point, the second feature point, the third feature point, and the fourth feature point, the two-dimensional inner aerodynamic profile is determined according to a fourth-order Bézier curve; and The two-dimensional outer aerodynamic profile is determined based on the two-dimensional inner aerodynamic profile and the width of the reverse airflow outlet. The first feature point is calculated in the following way: in, Let x be the x-coordinate of the first feature point. Let W be the ordinate of the first feature point, W be the width of the reverse airflow outlet, C be a preset third coefficient, and D be a preset fourth coefficient. Here, H is the first directional parameter, and H is the height of the reverse airflow when it is undisturbed. The second feature point is calculated in the following way: in, The x-coordinate of the second feature point is... The ordinate of the second feature point is... Let x be the x-coordinate of the first feature point. Let be the ordinate of the first feature point, and E be a preset fifth coefficient. This refers to the first direction parameter. The total pressure of the reverse airflow; The third feature point is calculated in the following way: in, The x-coordinate of the third feature point is... The ordinate of the third feature point is... The x-coordinate of the second feature point is... Let be the ordinate of the second feature point, and F be a preset sixth coefficient. This is the second direction parameter. The total pressure of the reverse airflow; The fourth feature point is calculated in the following way: in, The x-coordinate of the fourth feature point is... The ordinate of the fourth feature point is... The x-coordinate of the third feature point is... Let G be the ordinate of the third feature point, and G be a preset seventh coefficient. For the third-party parameter, The total pressure of the reverse airflow.

2. The method as described in claim 1, characterized in that, The first direction parameter is calculated in the following way: in, This refers to the first direction parameter. The radial velocity of the reverse airflow, The axial velocity of the reverse airflow; The second direction parameter is calculated in the following way: in, This refers to the first direction parameter. Here, A is the second direction parameter, and A is the preset first coefficient. The third-party parameter is calculated in the following way: in, This is the second direction parameter. Let B be the third-party directional parameter, and let B be the preset second coefficient.

3. The method as described in claim 1, characterized in that, Also includes: Obtain the friction distance corresponding to the maximum area of ​​the positive cross section of the reverse-thrust volute. The step of determining the two-dimensional outer aerodynamic profile based on the two-dimensional inner aerodynamic profile and the reverse thrust outlet width includes: The inlet and outlet diameters of the thrust reverser volute are determined based on the width of the thrust reverser airflow outlet. Based on the inlet diameter and the outlet diameter, a flow area variation curve for the two-dimensional outer aerodynamic profile is constructed according to a bicubic curve, wherein the travel distance corresponding to the maximum area of ​​the reverse-thrust volute cross-section is the extreme value of the bicubic curve; and The two-dimensional outer aerodynamic profile is determined based on the flow area change curve and the two-dimensional inner aerodynamic profile.

4. The method as described in claim 1, characterized in that, The step of determining the two-dimensional outer aerodynamic profile based on the two-dimensional inner aerodynamic profile and the reverse thrust airflow outlet width includes: The inlet and outlet diameters of the thrust reverser volute are determined based on the width of the thrust reverser airflow outlet. Based on the inlet diameter and the outlet diameter, construct the flow area variation curve of the two-dimensional outer aerodynamic profile according to the Vysinski curve, quintic curve, or shift-axis Vysinski curve; and The two-dimensional outer aerodynamic profile is determined based on the flow area change curve and the two-dimensional inner aerodynamic profile.

5. The method as described in claim 1, characterized in that, Also includes: Verify whether the thrust reverser housing with the two-dimensional inner aerodynamic profile and the two-dimensional outer aerodynamic profile meets the thrust reverser test requirements; as well as If the requirements for the reverse calculation test are not met, the first feature point, the second feature point, the third feature point, and the fourth feature point are re-determined using the normal distribution method.

6. The method as described in claim 5, characterized in that, Also includes: If the requirements for the reverse experiment are not met, reset the standard deviation of the normal distribution value taking method.

7. The method as described in claim 1, characterized in that, Also includes: Obtain the space limitation parameters of the test stand, and ensure that the size of the thrust reverser housing is not greater than the space limitation parameters of the test stand.

8. The method as described in claim 1, characterized in that, The thrust reverser housing is a C-shaped thrust reverser housing.

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