Aircraft nose noise reduction vortex generator device

Abstract

This invention belongs to the field of aircraft aerodynamic design technology and relates to an aircraft nose noise reduction vortex generator device. The device includes: 13 vortex generators; the 7th vortex generator is located directly behind the central circular light window of the spherical nose pod; the 13 vortex generators are arranged on both sides of the rear edge of the central circular light window of the spherical nose pod with the 7th vortex generator as the center; two symmetrically arranged vortex generators have the same shape, and from the sides to the middle, they are numbered as the first vortex generator, the second vortex generator, the third vortex generator, the fourth vortex generator, the fifth vortex generator, the sixth vortex generator, and the seventh vortex generator; among them, the seventh vortex generator is the shortest, and the vortex generators arranged on both sides of it increase in length sequentially; there is a gap between the front end of each vortex generator and the central circular light window; each vortex generator is arranged in the same direction as the flight path.

Description

Technical Field

[0001] This invention belongs to the field of aircraft aerodynamic design technology and relates to an aircraft nose noise reduction vortex generator device. Background Technology

[0002] Aircraft noise is mainly the result of high-speed airflow and the disturbance and relative motion of objects in the airflow. Noise sources can be divided into power plant noise, aircraft system noise, and airframe aerodynamic noise.

[0003] Aircraft aerodynamic noise is generated when an aircraft flies at high speed. As airflow flows around the aircraft, a boundary layer is created. The higher the speed, the greater the boundary layer transition and separation, and the higher the noise sound pressure level.

[0004] When airflow passes through the cavity, self-excited oscillations are generated inside the cavity. The aerodynamic noise generated by the coupling of the flow field and the sound field can cause structural vibration and fatigue damage, and even affect the service life of the structure. Therefore, how to control and reduce cavity aerodynamic noise has become a focus of research for scholars at home and abroad. Summary of the Invention

[0005] Purpose of the invention: This invention addresses the aerodynamic noise caused by spherical nose pods with complex cavities in aircraft by providing an eddy current generator device that can effectively reduce the noise level of such pods.

[0006] Technical solution:

[0007] An aircraft nose noise reduction eddy current generator device includes: 13 eddy current generators;

[0008] The seventh vortex generator is located directly behind the central circular light window of the spherical nose pod;

[0009] Thirteen vortex generators are arranged on both sides of the central circular light window of the spherical nose pod, with the seventh vortex generator as the center. The two symmetrically arranged vortex generators have the same shape and are arranged from the sides to the middle as the first vortex generator, the second vortex generator, the third vortex generator, the fourth vortex generator, the fifth vortex generator, the sixth vortex generator, and the seventh vortex generator.

[0010] Among them, the seventh vortex generator is the shortest, and the vortex generators arranged on both sides of it increase in length sequentially; there is a gap between the front end of each vortex generator and the central circular light window; each vortex generator is arranged in the same direction as the flight path.

[0011] Furthermore, the top shape of the first vortex generator is consistent with the curvature change of the spherical nose pod, the leading edge profile is a smooth arc curve, and the leading edge angle is 57°; the bottom length of the first vortex generator is 216mm, the tail height is 30mm, and the thickness is designed to be 2mm, and the thickness is uniform along the flight direction.

[0012] Furthermore, the top shape of the second vortex generator is consistent with the curvature change of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 52°. The bottom length of the second vortex generator is 208mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction.

[0013] Furthermore, the top shape of the third vortex generator is consistent with the curvature change of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 62°. The bottom length of the third vortex generator is 196mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction.

[0014] Furthermore, the top shape of the fourth vortex generator is consistent with the curvature change of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 71°; the bottom length of the fourth vortex generator is 160mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction.

[0015] Furthermore, the top shape of the fifth vortex generator is consistent with the curvature change of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 74°. The bottom length of the fifth vortex generator is 110mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction.

[0016] Furthermore, the top shape of the sixth vortex generator is consistent with the curvature change of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 72°; the bottom length of the sixth vortex generator is 87mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction.

[0017] Furthermore, the top shape of the seventh vortex generator is consistent with the curvature change of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 57°; the bottom length of the seventh vortex generator is 216mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction.

[0018] Beneficial effects

[0019] This invention designs a noise-reducing vortex generator for aircraft nose cones that can effectively reduce aerodynamic noise. For the complex spherical pod on the aircraft nose cone, CFD numerical simulation calculations show that, under most flight conditions such as different pod attitude angles, aircraft angle of attack, and sideslip angles, it improves airflow separation of the spherical pod to a certain extent, significantly reducing noise over a wide range, with a total sound pressure level reduction of approximately 5dB to 8dB under different conditions. Furthermore, this noise-reducing vortex generator has advantages such as simple structure, light weight, and minimal aircraft modification work. Attached Figure Description

[0020] This invention includes three accompanying drawings, and the drawings and their descriptions are as follows:

[0021] Figure 1a This is an external view of the first eddy current generator;

[0022] Figure 1b This is an external view of the second eddy current generator;

[0023] Figure 1c This is a schematic diagram of the third eddy current generator.

[0024] Figure 1d This is an external view of the fourth eddy current generator;

[0025] Figure 1e This is a schematic diagram of the fifth eddy current generator.

[0026] Figure 1f This is an external view of the sixth eddy current generator;

[0027] Figure 1g This is an external view of the seventh eddy current generator;

[0028] Figure 2 A schematic diagram (top view) of the installation of a noise reduction eddy current generator device for aircraft nose section;

[0029] Figure 3 A side view of the installation of a noise reduction eddy current generator device for aircraft nose section;

[0030] Wherein: 1-First eddy generator, 2-Second eddy generator, 3-Third eddy generator, 4-Fourth eddy generator, 5-Fifth eddy generator, 6-Sixth eddy generator, 7-Seventh eddy generator, 8-Spherical nose pod. Detailed Implementation

[0031] The following is a detailed description of the nose-mounted noise reduction eddy current generator device of the present invention, with reference to the accompanying drawings:

[0032] With the development of computational fluid dynamics and aeroacoustics, the research on cavity noise suppression mechanisms has become increasingly in-depth, and using noise reduction devices to suppress noise is an important measure.

[0033] The aircraft's nose is a spherical pod with an irregular spherical shape and irregular cavities, and it needs to perform multi-axis movements such as roll and pitch during flight. The aerodynamic shape of the aircraft's nose is complex. The spherical pod changes the original streamlined aerodynamic shape of the aircraft, has complex cavity flow characteristics, and poses a potential threat of airframe aerodynamic noise.

[0034] Therefore, this invention targets the spherical nose pod of the aircraft with a complex cavity. Through CFD numerical simulation calculation method, a vortex generator that can effectively reduce aerodynamic noise is designed to change the airflow field and reduce noise.

[0035] like Figures 1a-1g , Figure 2 and Figure 3 As shown, a nose-mounted noise reduction eddy current generator device is provided, comprising 13 eddy current generator components, each 2mm thick and 30mm high. Figure 2 As shown, the spanwise spacing between every two eddy current generators is 45 mm.

[0036] The top shape of the first vortex generator 1 is basically consistent with the curvature of the spherical nose pod 8, with a smooth arc-shaped leading edge profile and a leading edge angle of 57°. The bottom length of the first vortex generator 1 is 216mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. Two first vortex generators 1 are installed symmetrically on the left and right sides.

[0037] The top shape of the second vortex generator 2 is basically consistent with the curvature of the spherical nose pod 8, with a smooth arc-shaped leading edge profile and a leading edge angle of 52°. The bottom length of the second vortex generator 2 is 208mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. Two second vortex generators 2 are installed symmetrically on the left and right sides.

[0038] The top shape of the third vortex generator 3 is basically consistent with the curvature of the spherical nose pod 8, with a smooth arc-shaped leading edge profile and a leading edge angle of 62°. The bottom length of the third vortex generator 3 is 196mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. Two third vortex generators 3 are installed symmetrically on the left and right sides.

[0039] The top shape of the fourth vortex generator 4 is basically consistent with the curvature of the spherical nose pod 8, with a smooth arc-shaped leading edge profile and a leading edge angle of 71°. The bottom length of the fourth vortex generator 4 is 160mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. Two fourth vortex generators 4 are installed symmetrically on the left and right sides.

[0040] The top shape of the fifth vortex generator 5 is basically consistent with the curvature of the spherical nose pod 8, with a smooth arc-shaped leading edge profile and a leading edge angle of 74°. The bottom length of the fifth vortex generator 5 is 110mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. Two fifth vortex generators 5 are installed symmetrically on the left and right sides.

[0041] The top shape of the sixth vortex generator 6 is basically consistent with the curvature of the spherical nose pod 8, with a smooth arc-shaped leading edge profile and a leading edge angle of 72°. The bottom length of the sixth vortex generator 6 is 87mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. Two sixth vortex generators 6 are installed symmetrically on the left and right sides.

[0042] The top shape of the seventh vortex generator 7 is basically consistent with the curvature of the spherical nose pod 8, with a smooth arc-shaped leading edge profile and a leading edge angle of 57°. The bottom length of the seventh vortex generator 7 is 216mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. The seventh vortex generator 7 is located on the symmetry plane of the spherical nose pod 8, and there is only one.

[0043] This invention addresses the complex spherical pod on the nose of an aircraft. Through CFD numerical simulation, it employs an vortex generator that effectively reduces aerodynamic noise. Under most flight conditions, including varying pod attitude angles, aircraft angles of attack, and sideslip angles, it improves airflow separation within the spherical pod to a certain extent, significantly reducing noise over a wide range. The total sound pressure level is reduced by approximately 5dB to 8dB under different conditions. Furthermore, this noise-reducing vortex generator device has advantages such as simple structure, light weight, and minimal aircraft modification requirements.

Claims

1. A noise reduction eddy current generator device for aircraft nose cones, characterized in that, include: 13 eddy current generators; The seventh vortex generator is located directly behind the central circular light window of the spherical nose pod; Thirteen vortex generators are arranged on both sides of the central circular light window of the spherical nose pod, with the seventh vortex generator as the center. The two symmetrically arranged vortex generators have the same shape and are arranged from the sides to the middle as the first vortex generator, the second vortex generator, the third vortex generator, the fourth vortex generator, the fifth vortex generator, the sixth vortex generator, and the seventh vortex generator. Among them, the seventh vortex generator is the shortest, and the vortex generators arranged on both sides of it increase in length sequentially; there is a gap between the front end of each vortex generator and the central circular light window; each vortex generator is arranged in the same direction as the flight path; The top shape of the first vortex generator is consistent with the curvature change of the spherical nose pod, the leading edge profile is a smooth arc curve, and the leading edge angle is 57°; the bottom length of the first vortex generator is 216mm, the tail height is 30mm, and the thickness is designed to be 2mm, and the thickness is uniform along the flight direction. The top shape of the second vortex generator is consistent with the curvature change of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 52°. The bottom length of the second vortex generator is 208mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. The top shape of the third vortex generator is consistent with the curvature of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 62°. The bottom length of the third vortex generator is 196mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. The top shape of the fourth vortex generator is consistent with the curvature of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 71°. The bottom length of the fourth vortex generator is 160mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. The top shape of the fifth vortex generator is consistent with the curvature of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 74°. The bottom length of the fifth vortex generator is 110mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. The top shape of the sixth vortex generator is consistent with the curvature of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 72°. The bottom length of the sixth vortex generator is 87mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction. The top shape of the seventh vortex generator is consistent with the curvature of the spherical nose pod, and the leading edge profile is a smooth arc curve with a leading edge angle of 57°. The bottom length of the seventh vortex generator is 80mm, the tail height is 30mm, and the thickness is designed to be 2mm, with a uniform thickness along the flight direction.

Images