Nacelle, aircraft, method for designing a nacelle

Abstract

The application discloses an aero-engine nacelle, an aircraft, and an aero-engine nacelle design method. The aero-engine nacelle design method comprises the following steps: S1, obtaining a first transition position distribution of an outer surface of an aero-engine nacelle; S2, arranging an air suction slot in front of the first transition position, the air suction slot is configured to suck air from outside to inside of the nacelle, analyzing the aero-engine nacelle with the air suction slot, and obtaining a second transition position distribution; S3, adjusting the parameters of the air suction slot, repeating step S2, and obtaining the transition position distribution under different parameters of the air suction slot until the optimal aero-engine nacelle design scheme is obtained. By arranging the air suction slot in front of the first transition position, the laminar flow immersion area of the nacelle surface can be improved, thereby reducing the frictional resistance of the nacelle surface, improving the aerodynamic performance of the nacelle, and continuously adjusting the parameters of the air suction slot to ensure that the laminar flow area of the nacelle surface after arranging the air suction slot can be increased.

Description

Technical Field

[0001] This invention relates to the field of engine nacelles, and more specifically to an aircraft engine nacelle, an aircraft, and an aircraft engine nacelle design method. Background Technology

[0002] With the rapid development of high-bypass turbofan engine technology, the increase in their geometric dimensions has led to a rapid increase in the proportion of engine nacelle drag in the total engine drag. Nacelle surface friction is one of the main sources of nacelle drag. Therefore, reducing nacelle friction drag is essential. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defect of large frictional resistance of nacelles in the prior art, and to provide a design method for an aero-engine nacelle, an aircraft, and an aero-engine nacelle.

[0004] The present invention solves the above-mentioned technical problems through the following technical solution:

[0005] A method for designing an aircraft engine nacelle, the method comprising the following steps:

[0006] S1. Obtain the first transition position distribution on the outer surface of the aircraft engine nacelle;

[0007] S2. An air intake slit is arranged in front of the first transition position. The air intake slit is configured to draw air from outside the nacelle to inside. An analysis is performed on the aircraft engine nacelle with the air intake slit to obtain the distribution of the second transition position.

[0008] S3. Adjust the parameters of the air intake slot, repeat step S2, and obtain the distribution of transition positions under different air intake slot parameters until the optimal aircraft engine nacelle design scheme is obtained.

[0009] In this scheme, by arranging an air intake slit before the first transition position, the distribution of the second transition position is further back than that of the first transition position. This can increase the laminar flow wetting area on the nacelle surface, thereby reducing the frictional resistance of the nacelle surface and improving the aerodynamic performance of the nacelle. Furthermore, by continuously adjusting the parameters of the air intake slit and optimizing the distribution of the transition position, the laminar flow area on the nacelle surface after arranging the air intake slit can be increased.

[0010] Preferably, the parameters of the air intake slit include the width of the air intake slit, the air intake volume, the position of the air intake slit, and the number of air intake slits.

[0011] Preferably, the width of the air intake slit is adjustable in the range of 1 to 5 mm.

[0012] Preferably, the range of the inhalation volume is 0.05 to 0.2 kg / s.

[0013] Preferably, step S1 includes:

[0014] S11. Establish a mathematical model of the aerodynamic shape of the aircraft engine nacelle;

[0015] S12. Numerical simulation analysis is performed on the mathematical model of the aerodynamic shape of the aero-engine nacelle to obtain the distribution of transition positions on the surface of the aero-engine nacelle.

[0016] Preferably, step S2 includes:

[0017] S21. Adjust the parameters of the air intake slit by changing the mathematical model of the aerodynamic shape of the aircraft engine nacelle.

[0018] Preferably, the number of the air intake slits is one or more.

[0019] Preferably, the air intake slit is annular.

[0020] An aircraft engine nacelle is designed using the aircraft engine nacelle design method described above.

[0021] Preferably, the aircraft engine nacelle includes an air intake device located inside the aircraft engine nacelle and adjacent to the air intake slit.

[0022] An aircraft comprising an aircraft engine nacelle as described above.

[0023] The positive and progressive effects of this invention are as follows: The aero-engine nacelle design method of this invention, by arranging an air intake slit in front of the first transition position of the nacelle, makes the distribution of the second transition position more rearward than the distribution of the first transition position, which can increase the laminar flow wetting area on the nacelle surface, thereby reducing the frictional resistance of the nacelle surface and improving the aerodynamic performance of the nacelle. Furthermore, by continuously adjusting the parameters of the air intake slit and optimizing the distribution of the transition position, it is ensured that the laminar flow area on the nacelle surface after arranging the air intake slit can be increased. Attached Figure Description

[0024] Figure 1 This is a flowchart of an aircraft engine nacelle design method according to an embodiment of the present invention.

[0025] Figure 2 A schematic diagram of a mathematical model of an aircraft engine nacelle.

[0026] Figure 3 This is a diagram showing the distribution of the first transition position of an aircraft engine nacelle.

[0027] Figure 4 A diagram showing the transition points after installing an air intake slot in an aircraft engine nacelle, where the air intake slot does not draw in air.

[0028] Figure 5 A diagram showing the transition points after installing an air intake slot in an aircraft engine nacelle, at which point air is drawn in through the air intake slot.

[0029] Explanation of reference numerals in the attached figures

[0030] Aircraft engine nacelle 1

[0031] Air intake seam 2

[0032] First turning point 10

[0033] Second turning point 20 Detailed Implementation

[0034] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0035] This embodiment provides a method for designing an aircraft engine nacelle, such as... Figure 1 As shown, the aircraft engine nacelle design method includes the following steps:

[0036] S1. Obtain the first transition position distribution on the outer surface of the aircraft engine nacelle 1;

[0037] S2. An air intake slit is arranged in front of the first transition position. The air intake slit is configured to draw air from outside the nacelle to inside. An analysis is performed on the aircraft engine nacelle 1 with the air intake slit to obtain the distribution of the second transition position.

[0038] S3. Adjust the parameters of the air intake slot, repeat step S2, and obtain the distribution of transition positions under different air intake slot parameters until the optimal design scheme of the aircraft engine nacelle is obtained.

[0039] By arranging an air intake slit before the first transition position 10, the distribution of the second transition position 20 is further back than that of the first transition position. This increases the laminar flow wetting area on the nacelle surface, thereby reducing the frictional resistance of the nacelle surface and improving the aerodynamic performance of the nacelle. Furthermore, by continuously adjusting the parameters of the air intake slit and optimizing the distribution of the transition position, the laminar flow area on the nacelle surface after arranging the air intake slit can be increased.

[0040] Expanding the laminar flow region can effectively reduce frictional drag. At the same Reynolds number, the frictional drag of the turbulent boundary layer is approximately 10 times that of the laminar boundary layer. Delaying the transition as much as possible, expanding the laminar flow region on the model surface, and reducing the turbulent wetting area are effective means of reducing turbulent frictional drag and thus controlling flow.

[0041] Achieving laminar flow over a certain length on the outer surface of the nacelle is beneficial for reducing surface friction and improving the aircraft's fuel economy. In addition, the nacelle does not prioritize aerodynamic performance such as lift and torque, resulting in fewer constraints on aerodynamic design. Furthermore, it is not troubled by crossflow instability and adhesion line transition issues, making laminar flow drag reduction in the nacelle a very practical and feasible approach.

[0042] In a preferred embodiment, step S1 includes:

[0043] S11. Establish a mathematical model of the aerodynamic shape of the aircraft engine nacelle 1.

[0044] S12. Numerical simulation analysis is performed on the mathematical model of the aerodynamic shape of the aero-engine nacelle 1 to obtain the distribution of transition positions on the surface of the aero-engine nacelle 1.

[0045] As a preferred implementation, when establishing the mathematical model, firstly, a four-dimensional profile of the nacelle section is generated using a fourth-order NURBS curve. The profile is determined by the following formula:

[0046]

[0047] In the above formula, w i P represents the weighting factor of the NURBS curve. i is the control vertex of the NURBS curve; i is the number of the control vertex, weight factor, and spline basis function; n is the number of control vertices, weight factors, and spline basis functions; k is the order of the NURBS curve; u is the parameter of the NURBS curve, u i ≤u≤u i+1 basis function N i,k (u) is the k-th degree normalized B-spline basis function, usually derived from the "node vector" U = [u1, u2, ..., u n+k+1 (u0≤u1…≤u) n+k+1 The recursive definitions of de Boer and Cox are determined.

[0048] Secondly, third-order NURBS curves are used to generate the circumferential lines of the nacelle, forming the data framework for the nacelle's three-dimensional model. A schematic diagram of the nacelle's shape is shown below. Figure 2 As shown.

[0049] In this embodiment, step S2 includes:

[0050] S21. Adjust the parameters of the air intake slot by changing the mathematical model of the aerodynamic shape of the aircraft engine nacelle.

[0051] Numerical simulation analysis of the transition position distribution of the nacelle can save analysis time and costs and improve R&D efficiency.

[0052] During simulation, A transition model coupled with a k-ωSST turbulence model was used for numerical simulation analysis of the nacelle model to obtain the distribution of transition locations on the nacelle surface, such as... Figure 3 As shown. Using a mathematical model, numerical simulation can be used to obtain the distribution of the first transition position 10 on the surface of the aero-engine nacelle 1.

[0053] In step S3, the parameters of the air intake slot can include the width of the air intake slot, the air intake volume, the position of the air intake slot, and the number of air intake slots. The width of the air intake slot can be adjusted from 1 to 5 mm. The air intake volume can be adjusted from 0.05 to 0.2 kg / s. During simulation, the air intake volume can be initially set to a low value, and after obtaining the simulation results, the air intake volume can be gradually increased to obtain the transition distribution of the nacelle surface at different air intake volumes. Alternatively, the air intake volume at the air intake slot can be set to 0, that is, the transition distribution of the aero-engine nacelle surface can be analyzed when the air intake slot is not intakeing air, such as... Figure 4 As shown, this provides a certain reference for subsequent optimization design. When adjusting the position of the air intake slit 2, the ratio of the distance from the air intake slit 2 to the first transition position 10 to the distance from the front end of the aircraft engine nacelle to the first transition position 10 can be 0.3 to 0.7, preferably 0.4 to 0.6, and more preferably 0.5.

[0054] In a preferred embodiment, there is one air intake slit 2. In other preferred embodiments, there may be multiple air intake slits 2.

[0055] See Figure 4 and Figure 5 As shown, the air intake slit 2 is annular and is arranged along the circumference of the aircraft engine nacelle.

[0056] This embodiment also provides an aircraft engine nacelle, which is designed by the aircraft engine nacelle design method described above.

[0057] The aero-engine nacelle designed using the aforementioned aero-engine nacelle design method has lower surface friction drag, thus the aero-engine nacelle 1 has better aerodynamic performance, which is beneficial to improving the aircraft's economy.

[0058] The aircraft engine nacelle of this embodiment, by utilizing the aforementioned aircraft engine nacelle design method, can increase its laminar flow wetted area ratio by more than 15%, effectively reducing the frictional resistance of the nacelle surface. Specifically, it can be compared... Figure 3 and Figure 5 The simulation results.

[0059] The aircraft engine nacelle includes an air intake device located inside the nacelle and adjacent to the air intake slot 2. Alternatively, a negative pressure can be generated inside the air intake slot 2 using the engine's inherent gas-driven mechanism, thereby enabling the air intake slot 2 to draw in air.

[0060] This embodiment also provides an aircraft, which includes the aircraft engine nacelle as described above.

[0061] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for designing an aircraft engine nacelle, characterized in that, The aircraft engine nacelle design method includes the following steps: S1. Obtain the first transition position distribution on the outer surface of the aircraft engine nacelle; S2. An air intake slit is arranged in front of the first transition position. The air intake slit can draw air from outside the nacelle to inside. The distribution of the second transition position is obtained by analyzing the aircraft engine nacelle with the air intake slit. S3. Adjust the parameters of the air intake slot and repeat step S2 to obtain the distribution of transition positions under different air intake slot parameters until the design scheme of the aero-engine nacelle with the largest surface laminar flow area is obtained.

2. The aircraft engine nacelle design method as described in claim 1, characterized in that, The parameters of the air intake slit include the width of the air intake slit, the air intake volume, the position of the air intake slit, and the number of air intake slits.

3. The aircraft engine nacelle design method as described in claim 2, characterized in that, The width of the air intake slit can be adjusted from 1 to 5 mm.

4. The aircraft engine nacelle design method as described in claim 2, characterized in that, The range of the inhalation volume is 0.05 to 0.2 kg / s.

5. The aircraft engine nacelle design method as described in claim 1, characterized in that, Step S1 includes: S11. Establish a mathematical model of the aerodynamic shape of the aircraft engine nacelle; S12. Numerical simulation analysis is performed on the mathematical model of the aerodynamic shape of the aero-engine nacelle to obtain the distribution of transition positions on the surface of the aero-engine nacelle.

6. The aircraft engine nacelle design method as described in claim 5, characterized in that, Step S2 includes: S21. Adjust the parameters of the air intake slit by changing the mathematical model of the aerodynamic shape of the aircraft engine nacelle.

7. The aircraft engine nacelle design method as described in claim 1, characterized in that, The number of air intake slits is one or more.

8. The aircraft engine nacelle design method as described in claim 1, characterized in that, The air intake slit is annular.

9. An aircraft engine nacelle, characterized in that, The aircraft engine nacelle is designed using the aircraft engine nacelle design method as described in any one of claims 1-8.

10. The aircraft engine nacelle as described in claim 9, characterized in that, The aircraft engine nacelle includes an air intake device located inside the aircraft engine nacelle and adjacent to the air intake slit.

11. An aircraft, characterized in that, The aircraft includes an aircraft engine nacelle as described in claim 9 or 10.

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