Interconversion channel of circular channel and square channel and design method thereof

Abstract

The application provides a mutual conversion channel of a circular channel and a square channel and a design method thereof, which comprises the following steps: constructing geometric plane models of the circular channel and the square channel in the same plane, and making the geometric centers of the geometric plane models of the two channels be at the same coordinate origin; dividing the distance between any pair of parallel edge lengths in the square channel and the circular edge line of the circular channel into several equal distances, taking the any equal division point and the upper and lower two end points of the corresponding edge length as the reference to draw a circular arc line, so as to obtain several pairs of circular arc lines on both sides of any pair of parallel edge lengths; taking the several pairs of circular arc lines and the edge length of the square channel as the reference to draw several gradually changing surfaces, dividing the axial length of the mutual conversion channel into several equal intervals, and distributing the several gradually changing surfaces on the several equal intervals in sequence; scanning the boundary lines of the adjacent two surfaces along the axial direction of the mutual conversion channel to form connected spatial curved surfaces, and finally forming the mutual conversion channel.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of aero-engine test, and particularly relates to a mutual conversion channel of a circular channel and a square channel and a design method thereof. BACKGROUND

[0002] In some wind tunnel tests, the test channel of an aero-engine usually adopts a circular channel, while the test section of the aero-engine adopts a square channel for the convenience of installation of test pieces. When the test section and the test piece are connected, conversion from the circular channel to the square channel or conversion from the square channel to the circular channel is required.

[0003] Chinese patent CN106768803A discloses a subsonic circular-to-square aerodynamic nozzle. The method mainly aims at the design method of conversion from the circular channel to the square channel, involves a complex method, is suitable for specific use scenarios, and does not have universality. SUMMARY

[0004] The application aims to provide a mutual conversion channel of a circular channel and a square channel and a design method thereof, so as to solve or alleviate at least one problem in the background art.

[0005] The technical solution of the application is as follows: a design method of a mutual conversion channel of a circular channel and a square channel, comprising the following steps:

[0006] geometric plane models of the circular channel and the square channel are constructed in the same plane, and geometric centers of the geometric plane models of the circular channel and the square channel are located at the same coordinate origin;

[0007] distances between any pair of parallel sides in the square channel and a circular side line of the circular channel are divided into several equal distances along straight lines passing through center points of the corresponding side lengths and a center of the circle, any division point obtained by the division and upper and lower two end points of the corresponding side length of the square channel are taken as references to draw a circular arc line, so that several pairs of circular arc lines are obtained on both sides of the any pair of parallel sides;

[0008] several pairs of circular arc lines and the side length of the square channel are taken as references to draw several gradually changing surfaces, an axial length of the mutual conversion channel is divided into several equal intervals, and the several gradually changing surfaces are sequentially distributed on the several equal intervals of the axial length of the mutual conversion channel, so that the circular channel surface, the square channel surface and the gradually changing surfaces form a spatial geometric figure;

[0009] boundary lines of adjacent two surfaces in the circular channel surface, the square channel surface and the gradually changing surfaces are scanned along an axial direction of the mutual conversion channel to form connected spatial curved surfaces, and finally a mutual conversion channel of the circular channel and the square channel is formed.

[0010] In the preferred embodiment of the present application, the length of any pair of parallel sides of the square channel is longer than the length of the other pair of parallel sides of the square channel.

[0011] In the preferred embodiment of the present application, the distance between any pair of parallel sides of the square channel and the circular side line of the circular channel is divided into 3-5 parts along the straight line passing through the center point of the corresponding side and the center of the circle.

[0012] In the preferred embodiment of the present application, the number of parts into which the axial length of the mutual conversion channel is divided is the same as the number of parts into which the distance between the side length of the square channel and the circular side line of the circular channel is divided.

[0013] In the preferred embodiment of the present application, the geometric center of the plurality of gradually changing surfaces coincides with the axis of the mutual conversion channel.

[0014] In another aspect, the present application provides a technical solution: a mutual conversion channel of a circular channel and a square channel, wherein the mutual conversion channel is obtained by using any of the above-mentioned design methods for the mutual conversion channel of a circular channel and a square channel.

[0015] The design method for the mutual conversion and connection between the circular channel and the square channel provided by the present application has very strong versatility, is simple to use, and can efficiently and quickly solve the connection problem between the circular channel tester and the square channel test section in the process of testing an aero-engine. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions provided by the present application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the present application.

[0017] Figure 1 The figure is a design method for the mutual conversion channel of the present application.

[0018] Figure 2 The figure is a geometric plane diagram of the circular channel and the square channel in an embodiment of the present application.

[0019] Figure 3 The figure is a diagram of each surface in an embodiment of the present application.

[0020] Figure 4 The figure is a diagram of inserting each surface in an embodiment of the present application into the division point of the mutual conversion channel.

[0021] Figure 5 The figure is a diagram of the spatial geometry in an embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.

[0023] The application provides a design method for mutual conversion connection between a circular channel and a square channel with low flow loss.

[0024] As shown in Figure 1 The design method for mutual conversion between the circular channel and the square channel comprises the following steps:

[0025] Step S10: constructing geometric plane models of the circular channel and the square channel in the same plane, and making geometric centers of the circular channel and the square channel at the same coordinate origin.

[0026] As shown in Figure 2 The geometric plane model of the circular channel T1 and the square channel T2 is shown in the figure, in which the geometric centers of the geometric plane models of the circular channel T1 and the square channel T2 are the coordinate origin O.

[0027] Step S20: dividing a distance L between an arbitrary pair of parallel sides of the square channel T2 and a circular side line of the circular channel T1 into several equal distances along a straight line passing through a center point of the side and a center of the circle, taking any divided point and upper and lower two end points of the corresponding side of the square channel T2 as a reference to draw a circular arc line, and obtaining several pairs of circular arc lines on both sides of the parallel sides.

[0028] In the preferred embodiment of the application, the number of the divided distances is usually 3-5 equal parts. Further, the distance L between the pair of parallel sides with a longer length of the square channel T2 and the circular side line of the circular channel T1 is preferentially selected for division.

[0029] For example, in the embodiment shown in Figure 2 The distance L between the longer sides of the square channel T2 and the circular side line of the circular channel T1 is divided into 5 equal parts along a straight line passing through a center point of the longer side and a center of the circle, i.e. 4 equal parts are obtained, and the distance of each part is L / 5. The longer sides of the square channel T2 on both sides are divided in the same way. Then, the longer sides of the square channel T2 are taken as a reference to draw circular arc lines, which are denoted as S1, S2, S3 and S4, in which S0 is the circular side line of the circular channel T1, S5 is the longer side of the square channel T2, and S6 is the shorter side of the square channel T2.

[0030] Step S30: Using the paired circular arcs and the side length of the square channel obtained in step S20 as a reference, draw several gradually deformable surfaces. Divide the axial length of the mutual rotation channel (i.e., the part between the circular channel and the square channel) into several equally spaced parts, and distribute the above-mentioned gradually deformable surfaces in sequence on these several equally spaced parts. Thus, the circular channel surface, the square channel surface, and the gradually deformable surfaces constitute a spatial geometric figure, wherein the geometric center of the gradually deformable surfaces coincides with the axis of the mutual rotation channel.

[0031] In this application, the number of divisions of the axial length of the interchange channel is the same as the number of divisions of the distance between the side length of the square channel and the circular edge of the circular channel.

[0032] For example in Figure 3 As shown, four gradually deformable surfaces, denoted as S1', S2', S3', and S4', are drawn based on the parallel side lengths corresponding to the paired circular arcs and the square channel. S0' is the geometric surface of the circular channel T1, and S5' is the geometric surface of the square channel T2. Then, the axial length L1' of the interchange channel between the circular channel T1 and the square channel T2 is divided into 5 equal parts (i.e., 4 equal division points). The four gradually deformable surfaces S1', S2', S3', and S4' and the geometric surfaces S0' and S5' are then arranged according to... Figure 4 The arrangement of the elements is concentric along the axial direction, ultimately forming... Figure 5 The spatial geometry shown.

[0033] Step S40: Scan the boundary lines of two adjacent surfaces in the circular channel, square channel and gradient deformation surface along the axis of the mutual rotation channel to form a connected spatial surface, and finally form the mutual rotation channel of the circular channel and the square channel.

[0034] It should be noted that if a transition surface needs to be formed between the other pair of side lengths S6 of the square channel T2 and the circular edge S0 of the circular channel, the above steps S20 to S40 can be repeated.

[0035] Based on this, this application provides a channel that can switch between a circular channel and a square channel, which can be obtained using the design method described above.

[0036] The design method for converting between circular and square channels provided in this application has strong versatility, is simple to use, and can efficiently and quickly solve the connection problem between the circular channel tester and the square channel test section during aero-engine testing.

[0037] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for converting a circular channel into a square channel and vice versa, characterized in that, The application relates to a mutual conversion channel design method of a circular channel and a square channel. The geometric plane models of the circular channel and the square channel are constructed in the same plane, and the geometric centers of the geometric plane models of the circular channel and the square channel are located at the same coordinate origin; the distance between any pair of parallel edges of the square channel and the circular edge line of the circular channel is divided into several equal parts along a straight line passing through the center point of the corresponding edge and the center of the circle, and a circular arc line is drawn based on any division point and the upper and lower two end points of the corresponding edge of the square channel, so that a plurality of pairs of circular arc lines are obtained on both sides of the pair of parallel edges; a plurality of gradually changing surfaces are drawn based on the pairs of circular arc lines and the edges of the square channel, the axial length of the mutual conversion channel is divided into several equal intervals, and the gradually changing surfaces are sequentially distributed on the several equal intervals of the axial length of the mutual conversion channel, so that the circular channel surface, the square channel surface and the gradually changing surfaces form a spatial geometric figure; the boundary lines of the adjacent two surfaces in the circular channel surface, the square channel surface and the gradually changing surfaces are scanned along the axial direction of the mutual conversion channel to form connected spatial curved surfaces, and finally the mutual conversion channel of the circular channel and the square channel is formed.

2. The method of claim 1, wherein the method is characterized by: The pair of parallel edges of the square channel is a pair of longer edges of the square channel.

3. The method of claim 1 or 2, wherein The distance between the pair of parallel edges of the square channel and the circular edge line of the circular channel is divided into 3-5 parts along the straight line passing through the center point of the corresponding edge and the center of the circle.

4. The method of claim 3, wherein the square channel is a square channel having a width of 2.5 mm and a depth of 2.5 mm. The division number of the axial length of the mutual conversion channel is the same as the division number of the distance between the edges of the square channel and the circular edge line of the circular channel.

5. The method of claim 4, wherein the method further comprises: determining whether the number of the circular channels is equal to the number of the square channels; and if the number of the circular channels is not equal to the number of the square channels, then adjusting the number of the circular channels and the number of the square channels to be equal. The geometric centers of the gradually changing surfaces coincide with the axial center of the mutual conversion channel.

6. A mutual passage channel of a circular passage and a square passage, characterized by, The mutual conversion channel adopts the mutual conversion channel design method of the circular channel and the square channel according to any one of claims 1-5.

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