A circumferential distortion simulator based on an array of spoiler columns

Abstract

The application discloses a circumferential distortion simulator based on a spoiler column array, which comprises an air inlet, a central body fixed in the air inlet, a spoiler column support frame fixed on the central body and a plurality of spoiler columns, wherein the spoiler columns comprise circumferential spoiler columns and radial spoiler columns; the circumferential spoiler columns are uniformly arranged on the central body in a circumferential direction; the circumferential spoiler columns extend along the diameter direction of the central body; the radial spoiler column array is arranged on the spoiler column support frame; and the extending direction of the radial spoiler columns is parallel to the cross section of the central body. The low total pressure area generated by the fluid column spoiler is more uniform, and the situation that the total pressure area is too low can be avoided. The whole distortion simulator has small volume, less components, no redundant driving components, control components and the like, can be completely placed in the air inlet, is convenient to install and transport, and has simpler spoiler column manufacturing process and less consumables, so that the cost of the distortion simulator is significantly reduced, and the economy is improved.

Description

Technical Field

[0001] This invention relates to wind tunnel pressure testing for aircraft, specifically to a circumferential distortion simulator based on a turbulence column array. Background Technology

[0002] As modern military aircraft face increasingly stringent requirements for stealth and maneuverability, the design of their air intakes has become increasingly complex. This has forced many new air intake designs to sacrifice some aerodynamic performance to enhance stealth capabilities. This sacrifice is often achieved by bending the air intake profile, which increases internal flow separation, significantly complicates internal flow organization, and amplifies various distortions within the intake, leading to a series of complex flow problems. This makes the aircraft engine more prone to stall and surge, and in severe cases, may cause engine failure, endangering the pilot's life.

[0003] Among numerous flow problems, pressure distortion has the greatest impact on engine stability and is one of the key indicators determining aero-engine stability. Since different air intakes produce different outlet distortions, pressure distortion simulation devices are typically used to simulate the impact of pressure distortion on aero-engine stability. These devices artificially generate a pressure distortion flow field to simulate the outlet pressure distortion of the air intake during actual flight, thereby verifying engine performance and the compatibility between the air intake and the engine.

[0004] Most existing pressure distortion simulation devices are based on baffles. Their basic principle is to move the baffle to shield local areas within the airflow channel, causing varying degrees of disturbance and flow loss to the airflow. This creates a low-energy region downstream of the baffle, altering the distortion level at the outlet surface to meet different application requirements. However, these distortion simulators are typically fixed, limiting testing to only one distortion state at a time, resulting in low efficiency. Furthermore, installation and operation are complex; each change in the distortion simulation state requires disassembling and resealing the distortion simulation plate, lengthening the experimental cycle and increasing costs. Subsequent researchers designed movable baffle distortion simulators. These simulators use an external drive motor and transmission device to allow manual control of the baffle's displacement to accommodate different distortion flow fields and indices, significantly improving efficiency and reducing costs. However, their control systems are complex, construction and maintenance costs are high, test preparation time is long, and transmission displacement accuracy is low.

[0005] In addition, the plug-in type distortion simulator has some inherent problems: First, the degree of blockage of the fluid by the plug-in is not adjustable or the adjustment range is very limited, which leads to low control accuracy in the low total pressure zone after the plug-in and cannot meet many operating conditions; Second, if the windward area of ​​the plug-in is too large or the entire engine experimental model is too large, it will significantly increase the difficulty of fixing the plug-in, and the flow-blocking plug-in is prone to loosening during the experiment, thus causing unnecessary damage to the entire model; Finally, controlling multiple plug-ins at the same time requires multiple motors, which makes the entire device too large, increases the control system, and makes it more inconvenient for experiments. Summary of the Invention

[0006] Purpose of the invention: To address the above-mentioned shortcomings, the present invention provides a circumferential distortion simulator based on a turbulence column array, which is simple and compact, requires minimal manufacturing process, has low cost, and is widely applicable.

[0007] Technical Solution: To solve the above problems, the present invention employs a circumferential distortion simulator based on a spoiler column array, including an air intake, a central body fixed within the air intake, a spoiler column support frame fixed on the central body, and several spoiler columns. The spoiler columns include circumferential spoiler columns and radial spoiler columns. The circumferential spoiler columns are evenly arranged circumferentially on the central body and extend along the diameter direction of the central body. The radial spoiler column array is disposed on the spoiler column support frame, and the radial spoiler columns extend parallel to the cross-section of the central body.

[0008] Furthermore, the central body is connected axially to two rows of circumferential baffle columns by bolts, with the two rows of circumferential baffle columns arranged alternately.

[0009] Furthermore, the spoiler support frame is connected to two rows of radial spoilers along the central body axial direction by bolts. The two rows of radial spoilers are arranged alternately. The radial spoilers in the same row are arranged sequentially along the radial direction of the central body, and the height of the radial spoilers in the same row changes linearly from high to low. The radial spoilers closer to the central body are the highest. The radial spoilers are equal-diameter cylinders with a sloping top.

[0010] Furthermore, the central body is fixedly connected to two spoiler support frames. The two spoiler support frames are symmetrically arranged about the central body, and the extension directions of the two spoiler support frames coincide. Radial spoilers are arranged in an array on both spoiler support frames. One side of the spoiler support frame is connected to the central body, and the other side is spaced apart from the intake duct wall.

[0011] Furthermore, the spoiler support frame is symmetrically arrayed with radial spoilers on both the upper and lower sides.

[0012] Furthermore, the two ends of the spoiler support frame are the windward side and the leeward side, respectively. The windward side of the spoiler support frame is a curved surface that smoothly connects the upper and lower sides, minimizing flow loss.

[0013] Furthermore, the central body includes a front end portion, a support portion, and an end portion. The front end portion is a cone with a blunted tip and smoothly transitions to the support portion. The support portion is a cylinder, and the rear end of the support portion is connected to the end portion. The end portion is a truncated cone with a variable diameter. The turbulence column support frame and the turbulence column are both disposed on the support portion.

[0014] Furthermore, the central body is fixed inside the air intake duct by several central body support frames. The central body support frames are circumferentially fixed to the support part of the central body. One end of the central body support frame is fixedly connected to the central body, and the other end is fixedly connected to the inner surface of the air intake duct.

[0015] Furthermore, the cross-section of the central support frame is a hexagon with blunted vertices, and at least two sides of the hexagon are parallel to the incoming flow direction to minimize flow loss.

[0016] Furthermore, the air intake is a funnel-shaped converging pipe with both the inlet and outlet being circular.

[0017] Beneficial Effects: Compared with existing technologies, the significant advantages of this invention are: the low total pressure zone generated by the fluid cylinder turbulence is more uniform, avoiding excessively low total pressure. The entire distortion simulator is small in size, with fewer components, no redundant drive or control components, and can be completely placed inside the air intake, facilitating installation and transportation. Furthermore, the manufacturing process of the turbulence column is simpler, requiring less material, significantly reducing the cost and improving the economy of the distortion simulator. The range of experimental applicability is wider, and the device is simple and compact, requiring no redundant components, with minimal manufacturing requirements and low cost. Moreover, during the design and manufacturing process, the diameter, height, array pattern, and central body diameter of the turbulence column can be appropriately varied to meet different experimental requirements. The turbulence column can be replaced with bolts to accommodate different exit distortion conditions during aircraft flight. Different diameters, heights, and array patterns of the turbulence column correspond to the simulated operating conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal structure of the air intake of the circumferential distortion simulator of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the central body with a central body support frame and a turbulence column support frame provided on the central body in this invention;

[0020] Figure 3 This is a schematic diagram of the structure in this invention with a baffle column on the central body;

[0021] Figure 4 This is a schematic diagram comparing the outlet pressure of the aircraft's air intake numerical simulation calculation and the pressure measurement experiment using this distortion simulator under the same operating conditions. Figure 4(a) is the outlet pressure spectrum calculated by numerical simulation when the aircraft is flying at high altitude; Figure 4 (b) The outlet pressure spectrum obtained when a pressure measurement test is conducted on the ground using a circumferential distortion simulator without a turbulence column for the aircraft engine; Figure 4 (c) The outlet pressure spectrum obtained when a pressure measurement test is conducted on the ground using a circumferential distortion simulator equipped with the turbulence column of the present invention for an aircraft engine. Detailed Implementation

[0022] like Figure 1 As shown, this embodiment of a circumferential distortion simulator based on a spoiler column array includes an air intake duct 1, a central body, spoiler columns, a central body support frame 5, and a spoiler column support frame 6. The air intake duct 1 is a horn-shaped converging pipe with circular inlet and outlet. The central body is divided into a front end portion 2, a support portion 3, and an end portion 4. The front end portion 2 is a cone with a blunted tip that smoothly transitions to the subsequent section. The support portion 3 is a cylinder, and the end portion 4 is a frustum. The size of the central body can be changed according to the size of the subsequent components and the overall size of the device.

[0023] like Figure 2 As shown, the central body support frame 5 is a stretched hexagonal body with a blunted vertex cross-section. It is placed with its long side parallel to the incoming flow direction to minimize flow loss. It intersects with the central body and the inner wall of the intake duct. There are three central body support frames 5 in total, arranged in a ring at 120° intervals in the support part 3 of the central body. One end is connected to the central body inside the tube, and the other end is connected to the wall of the intake duct. There are two turbulence column support frames 6 in total, placed horizontally at 180° intervals in the support part 3 of the central body. The turbulence column support frame 6 is a cuboid with one end rounded. The blunted end is in front, and the right-angle end is behind. The surface obtained by stretching the curved side is the windward side, and the surface obtained by stretching the right-angle side is the leeward side to minimize flow loss. One side of the turbulence column support frame 6 is connected to the central body, and the other end is at a certain distance from the wall of the intake duct.

[0024] like Figure 3As shown, the spoiler columns are divided into circumferential spoiler columns 8 and radial spoiler columns 7. The circumferential spoiler columns 8 are all cylindrical bodies of uniform height, fixed to the support part 3 of the central body by bolt connection, and are evenly distributed in a circumferential ring, arranged in two staggered rows at equal intervals on the support part 3 of the central body (except at the spoiler column support frame 6). The radial spoiler columns 7 are cylindrical bodies with inclined tops, fixed to the spoiler column support frame 6 by bolt connection, and are evenly distributed from the inside to the outside from high to low. Two rows of radial spoiler columns 7 are arranged along the axial direction of the central body, and the two rows of radial spoiler columns 7 are evenly arranged in a staggered manner. In this embodiment, the inlet diameter of the air intake duct 1 is 745.06 mm, the outlet diameter is 389.5014 mm, the diameter of the front end portion 2 and the support portion 3 of the central body is 140 mm, the outlet diameter of the central body is 161.1022 mm, the length of the spoiler support frame 6 is 146.9616 mm, the width is 12 mm, and the height is 130 mm, the length of the central body support frame 5 is 76 mm, the width is 30 mm, and the height is 130.71 mm, and the circumferential spoiler column 8 has a diameter of 3 mm and a height of 65 mm. There are 36 columns in a row, with a distance of 20mm between two rows, a 10° interval between adjacent columns in the same row, and a 5° angle between adjacent columns in different rows. The radial columns are 7 columns with a diameter of 3mm and a height range of 95.97mm to 26.67mm. 13 columns are placed in a row on one side, with a 7mm interval between columns in the same row and a 10mm distance between the front and rear rows. The starting position of the first row of columns is 9.14mm from the center of the column, and the starting position of the second row of columns is 4.1mm from the center of the column.

[0025] like Figure 4 As shown in the example, Figure 4 (b) shows the outlet pressure graph of the ground using a circumferential distortion simulator without turbulence columns. Figure 4 The pressure distribution of the air intake outlet pattern of the aircraft shown in (a) during flight is basically consistent, such as Figure 4 As shown in (c), the low-energy region at the outlet surface is obtained after the circumferential distortion simulator is set with a turbulence column, and the low-energy region is uniform.

Claims

1. A circumferential distortion simulator based on a turbulence column array, characterized in that, It includes an air intake (1), a central body fixed inside the air intake (1), a spoiler support frame (6) fixed on the central body, and several spoiler columns. The spoiler columns include circumferential spoiler columns (8) and radial spoiler columns (7). The circumferential spoiler columns (8) are evenly arranged on the central body and extend along the diameter direction of the central body. The radial spoiler column array is set on the spoiler support frame (6) and the radial spoiler column extends parallel to the cross section of the central body. The central body is connected axially by bolts to two rows of circumferential baffle columns (8), which are arranged in an alternating pattern. The turbulence column support frame (6) is connected to two rows of radial turbulence columns (7) along the central body axial direction by bolts. The two rows of radial turbulence columns (7) are arranged in an alternating manner. The radial turbulence columns (7) in the same row are arranged in sequence along the radial direction of the central body, and the height of the radial turbulence columns in the same row changes linearly from high to low. The radial turbulence columns (7) closer to the central body are the highest. The central body is fixedly connected to two turbulence column support frames (6). The two turbulence column support frames (6) are symmetrically arranged about the central body, and the extension directions of the two turbulence column support frames (6) coincide. Radial turbulence columns (7) are arranged in an array on both turbulence column support frames (6). The central body includes a front end part (2), a support part (3) and an end part (4). The front end part (2) is a cone with a blunt tip and is smoothly connected to the support part (3). The support part (3) is a cylinder. The rear end of the support part (3) is connected to the end part (4). The end part (4) is a truncated cone with a variable diameter. The turbulence column support frame (6) and the turbulence column are both located on the support part (3). The central body is fixed inside the air intake (1) by a number of central body support frames (5). The central body support frames (5) are circumferentially fixed to the support part (3) of the central body. One end of the central body support frame (5) is fixedly connected to the central body, and the other end is fixedly connected to the inner surface of the air intake. The cross-section of the central body support frame (5) is a hexagon with blunted vertices, and at least two sides of the hexagon are parallel to the incoming flow direction.

2. The circumferential distortion simulator according to claim 1, characterized in that, The turbulence column support frame (6) has radial turbulence columns (7) arranged symmetrically on the upper and lower sides.

3. The circumferential distortion simulator according to claim 1, characterized in that, The two ends of the spoiler support frame (6) are the windward side and the leeward side, respectively. The windward side of the spoiler support frame (6) is a curved surface that smoothly connects the upper and lower sides.

4. The circumferential distortion simulator according to claim 1, characterized in that, The air intake (1) is a funnel-shaped constricting pipe with circular inlet and outlet.

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