A sphere structure for an air intake rectifying device and a spherical surface segmentation method thereof

Abstract

The application provides a spherical surface segmentation method for a ball structure of an air intake rectifying device, and belongs to the technical field of aero-engine testing. The spherical surface segmentation method comprises the following steps: based on the contour size of the ball structure, a regular polyhedron is inscribed in the ball, an equilateral triangle is drawn in each face of the regular polyhedron, and the center points of each hexagon formed by the equilateral triangles are determined; the center points of the hexagons are projected onto a spherical surface, thereby forming spherical projection points; an excircle of the spherical surface is drawn through the spherical projection points, and the intersection lines formed by the intersection of adjacent excircles of the excircle constitute frame edge lines, thereby forming a frame model. The method provided by the application solves the problem that the edges of the polygon are not coplanar in the spherical surface segmentation of the prior art, and can ensure that the edges of all polygons are located on the same plane, thereby ensuring that the shape of the ball structure of the air intake rectifying device is a completely closed global grid ball top.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aero-engine noise test, and particularly relates to a spherical structure for an air inlet fairing device and a spherical surface segmentation method thereof. BACKGROUND

[0002] In order to design and develop an aero-engine with low noise level, a large number of noise tests need to be carried out. In the process of carrying out noise tests, in order to accurately simulate the engine noise characteristics in actual flight, the air inlet fairing device is needed to rectify the air inlet vortex in the ground test, the engine inlet extends into the air inlet fairing device, the secondary noise induced by the vortex and the fan interference is eliminated through the air inlet fairing device, the smooth propagation of the fan noise is maximized, and the correctness of the engine inlet sound source characteristics is ensured.

[0003] The key structure of the air inlet fairing device is a grid spherical structure. The grid spherical structure is to divide the spherical surface into a plurality of polygons, and each polygon is taken as an independent unit for subsequent design and processing. Since the hexagonal honeycomb structure has the advantages of strong bearing capacity, exquisite structure and material saving, the existing grid spherical structure is mostly composed of hexagons to form a polyhedron, which helps to obtain a solid and light spherical frame structure.

[0004] The existing grid spherical structure surface segmentation method is based on the spherical surface inscribed regular polyhedron, and the spherical surface is divided into a plurality of polygons by the intersection of the spherical surface and the straight line from the center of the spherical surface to the vertex of the regular polyhedron. Figure 1 As shown in FIG. 2, the spherical surface is first inscribed with a regular 272-polyhedron, and then each face of the regular 272-polyhedron is further segmented. The intersection point of the segmentation is projected to the spherical surface along the straight line from the center of the spherical surface to the intersection point to obtain a segmentation point projection point, as shown in FIG. 3. Figure 2 In addition, the orientation and size of the space polygon edge need to be adjusted to obtain a planar polygon during the processing and manufacturing of the grid spherical structure, as shown in FIG. 4. After segmentation by this segmentation technology, the polygon at the vertex of the regular 272-polyhedron is a pentagon, and the others are hexagons. Figure 3

[0005] After the preliminary segmentation of the spherical surface in the prior art, the edges of the polygon are not necessarily coplanar, and the length and orientation of the polygon edge need to be manually adjusted so that the edges of the single polygon are located in the same plane, which is relatively complex. The size and number of the divided polygons are limited by the design requirements such as the size of the spherical surface, the processing capacity requirement, and the roughness of the spherical surface. With the further development of engine noise test technology, the demand for the size of the spherical structure of the air inlet fairing device is further increased, and the number of the segmented spherical structure is further increased due to the limitation of the processing size of the unit. The existing segmentation method will greatly increase the design workload.

[0006] ​In addition, the length and orientation of the polygon edges cannot be guaranteed to be on the same plane after artificial adjustment, and other measures need to be considered for reliable installation of the part of the polygon. For the same size sphere, due to the difference between designers, the adjustment method of the edges of a single polygon on the same plane may be different, and the distance from the vertex to the sphere center after adjustment changes, and the distance from each face of the polyhedron to the sphere center also changes, which will lead to the difficulty of implementing unified standards for the sphere top frame model. SUMMARY

[0007] The purpose of the present application is to provide a sphere structure for an air intake flow regulation device and a sphere surface segmentation method thereof to solve or alleviate at least one problem in the background art.

[0008] The technical solution of the present application is: a sphere surface segmentation method for a sphere structure of an air intake flow regulation device, comprising:

[0009] Based on the contour size of the sphere structure, a regular polyhedron is inscribed in the sphere, and an equilateral triangle is drawn in each face of the regular polyhedron to determine the center point of each hexagon formed by the equilateral triangles;

[0010] The center point of the hexagon is projected onto the sphere surface to form a sphere projection point;

[0011] An outer tangent plane of the sphere is drawn through the sphere projection point, and the intersection lines of adjacent outer tangent planes constitute frame edge lines to form a frame model.

[0012] Further, the contour of the sphere structure includes an outer contour and an inner contour.

[0013] Further, the outer contour of the sphere structure forms an outer frame edge line, and the inner contour of the sphere structure forms an inner frame edge line, and the outer frame edge line and the inner frame edge line are connected to form a frame model with a predetermined thickness.

[0014] On the other hand, the technical solution provided by the present application is: a sphere structure for an air intake flow regulation device, which is obtained by using any of the sphere surface segmentation methods for an air intake flow regulation device as described above.

[0015] The sphere structure outer tangent plane segmentation method provided by the present application provides a more convenient method for sphere top structure sphere surface segmentation of an air intake flow regulation device, solves the problem of polygon edges not being coplanar in the sphere surface segmentation of the prior art, and guarantees that all polygon edges are on the same plane, thereby guaranteeing that the shape of the sphere structure of the air intake flow regulation device is a fully closed global spherical grid sphere top. The method does not have an artificial adjustment process, and the finished product model can implement unified standards, i.e., the distance from the sphere center to each polygon face is the radius of the sphere. Attached Figure Description

[0016] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0017] Figure 1 This is a schematic diagram of the polygon inside one face of a regular icosahedron in the prior art.

[0018] Figure 2 This is a schematic diagram of the icosahedral segmentation projection in the prior art.

[0019] Figure 3 This is a schematic diagram of a polygon obtained in the prior art.

[0020] Figure 4 This is a schematic diagram of the spherical structure spherical segmentation method of this application.

[0021] Figure 5 This is a schematic diagram of a regular icosahedron inscribed in a sphere according to one embodiment of this application.

[0022] Figure 6 for Figure 5 A schematic diagram of an icosahedron in which equilateral triangles are equally divided within one face.

[0023] Figure 7 This is a front view of the spherical projection point of the center point of the hexagon projected onto the sphere in this embodiment of the application.

[0024] Figure 8 This is a side view of the spherical projection point of the hexagonal center point projected onto the sphere in this embodiment of the application.

[0025] Figure 9 This is a schematic diagram of the circumferential surface of the spherical projection point in this embodiment of the present application.

[0026] Figure 10 This is a schematic diagram of the intersection line between the outer tangent plane M1 and the outer tangent plane M3 in this embodiment of the present application.

[0027] Figure 11 This is a schematic diagram of the intersection line between the outer tangent surface M1 and the outer tangent surfaces M2 to M7 in this embodiment of the present application.

[0028] Figure 12 This is a schematic diagram of the hexagonal shape enclosed by the external tangent lines in this embodiment of the application.

[0029] Figure 13 This is a schematic diagram of the outer edge and inner edge of the frame in this embodiment of the application.

[0030] Figure 14 This is a schematic diagram of the frame model formed by the outer edge and inner edge of the frame in this embodiment of the application.

[0031] Figure 15 The frame model schematic diagram of one face of the icosahedron in this embodiment of the application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme of the embodiments of the application will be described in more detail below with reference to the drawings in the embodiments of the application.

[0033] In order to solve the problem that the polygon edges are not coplanar after the preliminary segmentation of the spherical surface, realize that all the polygon edges are located on the same plane, ensure that the shape of the spherical structure in the air intake fairing device is a completely closed global grid spherical dome, and at the same time realize that for a spherical body of a certain size, the distance from each face of the segmented polyhedron to the spherical center is certain, the spherical dome frame model can realize a unified standard, the application provides a spherical surface segmentation method for a spherical structure.

[0034] As shown in Figure 4 The spherical surface segmentation method for the spherical structure of the air intake fairing device provided by the application includes the following steps:

[0035] Step S1, determining the outer contour size of the spherical structure, based on the outer contour size, inscribing a regular polyhedron in the spherical body, dividing a regular triangle in each face of the regular polyhedron, and finding the center points of each hexagon formed by the divided regular triangles.

[0036] As shown in Figure 5 The schematic diagram of the regular icosahedron inscribed in the spherical body in this embodiment of the application is shown in Figure 6 The divided regular triangle in one face of the regular icosahedron is shown in

[0037] Step S2, projecting the center points of the hexagons in step S1 onto the spherical surface, thereby forming spherical projection points.

[0038] As shown in Figure 7 and Figure 8 The front view and side view of the spherical projection points obtained by projecting the center points of the hexagons onto the spherical surface.

[0039] Step S3, drawing the tangent plane of the spherical surface through the spherical projection points, and the intersection lines of the adjacent tangent planes constitute the frame outer edge lines.

[0040] As shown in Figure 9 and Figure 10 Taking the middle tangent plane M1 as an example, the tangent planes M2-M7 are distributed around the tangent plane M1, the tangent plane M3 has an intersection line J1 with the tangent plane M1, and similarly, Figure 11As shown, the external tangent plane M6 intersects with external tangent plane M1 by line J2; external tangent plane M4 intersects with external tangent plane M1 by line J3; external tangent plane M7 intersects with external tangent plane M1 by line J4; external tangent plane M5 intersects with external tangent plane M1 by line J5; and external tangent plane M2 intersects with external tangent plane M1 by line J6. Figure 12 As shown, the intersection lines J1 to J6 form a hexagon, which is the outer edge of the frame.

[0041] Step S4: Determine the inner contour dimensions of the spherical structure. Repeat the above steps to obtain the inner edge line of the frame. Form the frame model, i.e., the spherical structure of the air intake device, by connecting the outer edge line of the frame with the inner edge line of the frame.

[0042] Since the frame of the sphere structure is a solid structure with a certain thickness, this application also determines the inner edge line of the frame based on the inner contour dimensions of the sphere structure and steps S1 to S3. For example... Figure 13 The figure shows the outer edge K1 and inner edge K2 of the frame obtained in this embodiment of the application. Connecting the outer edge K1 and inner edge K2 yields a frame model with a certain thickness, as shown. Figure 14 The example shown is a frame model of a single hexagonal structure. Ultimately, a frame model of the entire spherical structure can be obtained, as shown below. Figure 15 As shown.

[0043] The spherical structure external tangent segmentation method provided in this application offers a more convenient approach to spherical segmentation of the dome structure of an air intake rectifier. It solves the problem of non-coplanar edges of polygons in existing spherical segmentation techniques. This method ensures that all polygon edges lie on the same plane, thus guaranteeing that the shape of the spherical structure of the air intake rectifier is a completely closed global grid dome. Because this method eliminates the need for manual adjustments, the finished model can achieve a uniform standard, where the distance from the center of the sphere to the face of each polygon is equal to the radius of the sphere.

[0044] Finally, this application also provides a spherical structure for an intake rectifier, which employs the spherical segmentation method described above.

[0045] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for dividing a spherical surface of a sphere structure for an air intake fairing apparatus, characterized by, The method comprises the following steps: Based on the outline size of the spherical structure, a regular polyhedron is inscribed in the sphere, the regular polyhedron is a regular icosahedron, and an equilateral triangle is drawn in each face of the regular polyhedron, and the center points of each hexagon formed by the equilateral triangles are determined; The center points of the hexagons are projected onto the spherical surface to form spherical projection points; An outer tangent plane of the spherical surface is drawn through the spherical projection points, and the intersection lines of the adjacent outer tangent planes constitute frame edge lines to form a frame model.

2. The spherical surface dividing method for the ball structure of the air intake rectifier device according to claim 1, characterized by, The outline of the spherical structure comprises an outer outline and an inner outline.

3. The spherical surface dividing method for the ball structure of the air intake rectifier device according to claim 2, characterized by, Based on the outer outline of the spherical structure, an outer frame edge line is formed, and based on the inner outline of the spherical structure, an inner frame edge line is formed, and the outer frame edge line and the inner frame edge line are connected to form a frame model with a predetermined thickness.

4. A sphere structure for an air intake fairing device, characterized by, The spherical structure is obtained by the spherical surface segmentation method for the spherical structure of the air inlet rectifying device according to any one of claims 1 to 3.

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