Wind tunnel air inlet test throttling cone system with wide adjustment range and use method

Abstract

The invention provides a wind tunnel air inlet test throttling cone system with a wide adjustment range and a use method, and the system comprises a large-flow cylinder, the front end of the large-flow cylinder is detachably connected with a small-flow cylinder, the two ends of a large lead screw are rotatably connected to the circle center positions of the front end and the rear end of the large-flow cylinder respectively, one end of the small lead screw is fixedly connected with the large lead screw, and the other end of the small lead screw is fixedly connected with the small-flow cylinder. The other end of the small lead screw is rotationally connected with the circle center position of the front end face of the small-flow cylinder. A large throttling cone is arranged on the large lead screw, and the outer side of the large throttling cone is circumferentially fixed through a large throttling cone guide rail; a small throttling cone is arranged on the small lead screw, and the outer side of the small throttling cone is circumferentially fixed through a small throttling cone guide rail. The device is used for carrying out back pressure regulation on different air inlet duct test models, can be matched with air inlet duct wind tunnel test models with different outlet diameters, and has wide-range flow regulation capability and back pressure regulation capability; and the flow adjusting capacity and the back pressure adjusting capacity with different precisions are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of aerodynamics, and in particular to a throttle cone system for a wind tunnel inlet test with a wide adjustment range and a use method thereof. Background Art

[0002] Wind tunnel testing is one of the main means of evaluating the performance of the air-breathing aircraft inlet. It can measure the static and dynamic aerodynamic characteristics of the inlet, including the total pressure recovery coefficient σ, flow coefficient φ, surge boundary and various types of distortion index, etc., to provide test data for the inlet design to ensure that the performance of the inlet in the entire flight envelope can meet the requirements of the engine. In the inlet test, a throttling system is usually used to adjust the inlet outlet flow and thus change the outlet back pressure, thereby simulating the change of the downstream back pressure of the inlet during actual flight, and then evaluating the inlet's ability to resist back pressure and the performance parameters under different back pressure conditions.

[0003] The existing inlet test throttling system usually consists of only a single cone and a single flow cylinder. Each system is suitable for inlet models with a specific outlet size range and does not have a wide range and high-precision flow regulation capability. On the one hand, if a small-sized throttling system is used to match a large-sized inlet model, the internal flow channel will be too blocked and the required performance parameters cannot be obtained. On the other hand, if a large-sized throttling system is used to match a small-sized inlet model, the throttling cone position is not easy to give due to insufficient flow regulation accuracy, and it is difficult to adjust the flow and outlet back pressure under the required state, which will also increase the test cycle and test cost. Therefore, wind tunnels are usually equipped with throttling systems of different sizes, but these throttling systems are independent systems, each of which is adapted to the corresponding motor device and control system, which increases economic and maintenance costs.

[0004] The throttling system for wind tunnel inlet duct test with a wide adjustment range described in the present invention can be matched with inlet duct models with different outlet sizes, thereby increasing the scope of application of the throttling cone system; in addition, the flow adjustment accuracy of the throttling cone system is different when using different flow tubes, which can meet the requirements of different inlet duct tests for flow adjustment accuracy. In view of the problems of insufficient flow adjustment range and insufficient flow adjustment accuracy of existing inlet duct wind tunnel test throttling systems, it is necessary to propose a throttling cone system for wind tunnel inlet duct test with a wide adjustment range and a method for use. Summary of the invention

[0005] The object of the present invention is to provide a wind tunnel inlet test throttle cone system with a wide adjustment range and a method of use, which has a wide range of flow regulation capabilities and back pressure regulation capabilities; and has flow regulation capabilities and back pressure regulation capabilities with different precisions.

[0006] According to one object of the present invention, the present invention provides a throttle cone system for a wind tunnel inlet test with a wide adjustment range, comprising a large flow tube, a small flow tube, a large lead screw and a small lead screw, wherein the front end of the large flow tube is detachably connected to the small flow tube, the two ends of the large lead screw are respectively rotatably connected to the center position of the front end and the rear end of the large flow tube, one end of the small lead screw is fixedly connected to the large lead screw, and the other end of the small lead screw is rotatably connected to the center position of the front end surface of the small flow tube;

[0007] The large lead screw is provided with a large throttling cone, and the outer side of the large throttling cone is circumferentially fixed by a large throttling cone guide rail; the small lead screw is provided with a small throttling cone, and the outer side of the small throttling cone is circumferentially fixed by a small throttling cone guide rail.

[0008] Furthermore, it also includes a motor, which is fixed to the downstream end of the large flow tube through a motor support, and the front end of the output shaft of the motor is connected to the large screw through a first transmission key.

[0009] Furthermore, a flange is provided on the small diameter cylindrical end surface of the large flow cylinder, and the small flow cylinder is connected to the large flow cylinder via the flange.

[0010] Furthermore, the outer wall thread of the large lead screw matches the inner wall thread of the central through hole of the large throttling cone, and the outer wall thread of the small lead screw matches the inner wall thread of the central through hole of the small throttling cone.

[0011] Furthermore, the outer shape of the large flow cylinder includes a small diameter cylindrical section, a large diameter cylindrical section and a transition section between the two cylindrical sections. When the large throttling cone moves axially back and forth, the minimum cross-sectional area between the outer wall surface of the large throttling cone and the inner wall surface of the transition section of the large flow cylinder, that is, the air flow area, changes.

[0012] Furthermore, the outer wall surface of the large throttling cone includes a conical section and a cylindrical section. When the interface between the conical section and the cylindrical section coincides with the small end surface of the transition section of the large flow tube, the airflow area is the smallest. When the interface between the conical section and the cylindrical section coincides with the large end surface of the transition section of the large flow tube, the airflow area is the largest.

[0013] Furthermore, the diameter of the straight section of the large throttling cone is the same as the diameter of the small end surface of the transition section of the large flow tube.

[0014] Furthermore, the small flow cylinder includes a transition section and a cylindrical section. The cylindrical section has a smaller diameter and a flange on the end face for matching the outlet end of a small-diameter inlet duct test model. The large end face diameter of the transition section is the same as the small diameter cylindrical section diameter of the large flow cylinder. The transition section end face of the small flow cylinder is provided with a flange for combination with the large flow cylinder.

[0015] According to another object of the present invention, the present invention provides a method for using the above-mentioned wind tunnel inlet test throttle cone system with a wide adjustment range, comprising the following steps:

[0016] S1. When the design flow rate of the inlet model is large, the small flow tube is removed and the large flow tube is used alone for the test; when conducting the inlet test, the end face of the large flow tube is connected to the outlet of the inlet, and the motor command is input to control the motor to rotate, thereby moving the large throttle cone axially;

[0017] As the large throttle cone moves forward, the flow area between the wall of the large throttle cone and the large flow tube decreases. As the flow area decreases, the flow rate allowed to pass is also getting smaller and smaller, and the back pressure at the inlet duct outlet is getting larger and larger. When the large throttle cone moves forward to the front end position, the wall of the large throttle cone and the wall of the large flow tube are closed. At this time, the flow rate allowed to flow is zero, and the back pressure at the inlet duct outlet reaches the maximum limit.

[0018] S2. Connect the small flow cylinder, small lead screw and small throttling cone to the front end of the throttling cone system. The large lead screw drives the small lead screw to rotate, and then drives the small throttling cone to move back and forth to change the cross-sectional back pressure. At this time, under the same number of pulses, the flow area change caused is smaller, and the back pressure regulation accuracy at the inlet duct outlet is higher. At the same time, the minimum flow area between the outer wall of the small throttling cone and the inner wall of the small flow cylinder is always smaller than the throttling area between the outer wall of the large throttling cone and the inner wall of the large flow cylinder, so that the small throttling cone always plays the role of back pressure regulation. When the large throttling cone and the small throttling cone move to the front end position, the small throttling cone has moved to the front end, so that the flow area in the flow channel is reduced to 0, while there is still a certain space between the large throttling cone and the large flow cylinder.

[0019] Furthermore, when the two flow cylinders are used in combination, since the minimum flow area between the small flow cylinder and the small throttling cone is smaller than the minimum flow area between the large flow cylinder and the large throttling cone, the former plays a role in back pressure regulation; when the small throttling cone is adjusted, the large throttling cone stroke L1 is greater than the small throttling cone stroke L2.

[0020] The technical solution of the present invention is used to adjust the back pressure for different inlet test models. Its upstream is generally connected to the inlet outlet or connected to the inlet outlet through other pipelines, and its downstream can be directly exposed to the flow field or connected to other components such as flow meters and ejectors through pipelines. It can match inlet wind tunnel test models with different outlet diameters, and has a wide range of flow regulation capabilities and back pressure regulation capabilities; it has flow regulation capabilities and back pressure regulation capabilities with different precisions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of a throttling system connected to a large-size outlet inlet duct model according to an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of a throttling system connected to a small-sized outlet inlet duct model according to an embodiment of the present invention;

[0025] In the figure: 1. motor; 2. motor support; 3. large flow tube; 4. large throttling cone guide; 5. first transmission key; 6. first bearing; 7. large throttling cone; 8. large lead screw; 9. second bearing; 10. second transmission key; 11. small throttling cone guide; 12. small flow tube; 13. small throttling cone; 14. third bearing; 15. small lead screw. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Example 1

[0030] like Figure 1 As shown,

[0031] A throttle cone system for a wind tunnel inlet test with a wide adjustment range comprises a motor 1, a motor support 2, a large flow tube 3, a large throttle cone guide rail 4, a first transmission key 5, a first bearing 6, a large throttle cone 7, a large lead screw 8, a second bearing 9, a second transmission key 10, a small throttle cone guide rail 11, a small flow tube 12, a small throttle cone 13, a third bearing 14 and a small lead screw 15, wherein:

[0032] The motor 1 is fixed to the downstream end of the large flow tube 3 through the motor support 2, and the front end of the output shaft of the motor 1 is connected to the large screw 8 through the first transmission key 5, so that the circumferential movement of the motor shaft is transmitted to the large screw 8; the large screw 8 is fixed to the center position of the large flow tube 3 through the first bearing 6, so that it is fixed radially; a large throttling cone 7 is installed on the large screw 8, and the outer wall thread of the large screw 8 matches the inner wall thread of the central through hole of the large throttling cone 7, and the outer side of the large throttling cone 7 is circumferentially fixed by the large throttling cone guide 4; under this structure, when the motor 1 rotates, the circumferential movement of the motor shaft can be converted into the axial movement of the large throttling cone 7.

[0033] The outer shape of the large flow tube 3 can be divided into three sections: a small diameter cylindrical section, a large diameter cylindrical section and a transition section between the two cylindrical sections. When the large throttling cone 7 moves forward and backward along the axial direction, the minimum cross-sectional area (i.e., the air flow area) between the outer wall surface of the large throttling cone 7 and the inner wall surface of the transition section of the flow tube will change. A flange is provided on the small diameter cylindrical end surface of the large flow tube 3 to facilitate connection with the small flow tube 12.

[0034] At the same time, the outer wall surface of the large throttling cone 7 can also be divided into two sections: a conical section and a cylindrical section. When the interface between the two sections coincides with the small end face of the transition section of the large flow tube 3, the airflow area is the smallest. When the interface between the two sections coincides with the large end face of the transition section of the large flow tube, the airflow area is the largest. Usually, the diameter of the straight section of the large throttling cone 7 is the same as the diameter of the small end face of the transition section of the large flow tube 3 to ensure that the airflow area can be reduced to zero. In addition, the cone surface generatrix of the large throttling cone 7 and the transition section generatrix of the large flow tube 3 can be designed as a straight line or other curved shapes.

[0035] The end of the large lead screw 8 is fixed at the center of the front end surface of the large flow tube 3 through the second bearing 9, and the large lead screw 8 and the small lead screw 15 are connected together through the second transmission key 10, thereby transmitting the circumferential motion of the motor 1 to the small lead screw 15.

[0036] Similarly, the outer wall thread of the small lead screw 15 and the inner wall thread of the central through hole of the small throttle cone 13 cooperate with each other to connect the two parts, and a small throttle cone guide rail 11 is provided on the outer side of the small throttle cone 13 to fix the small throttle cone 13 circumferentially, converting the circumferential motion transmitted from the front of the motor 1 into the axial motion of the small throttle cone 13. The end of the small lead screw 15 is fixed on the cylindrical front end surface of the small flow cylinder 12 through the third bearing 14.

[0037] The small flow tube 12 is divided into two sections: a transition section and a cylindrical section. The cylindrical section has a smaller diameter and a flange designed on the end face to match the outlet end of the small-diameter inlet duct test model. The large end face diameter of the transition section is the same as the diameter of the small-diameter cylindrical section of the large flow tube 3. At the same time, a flange is designed on the end face for combination with the large flow tube 3. When used in combination, a sealing ring is installed at the connection position or silicone rubber is applied to ensure the air tightness of the throttling cone system.

[0038] The present invention has two flow tubes with different calibers, namely, a large flow tube 3 and a small flow tube 12. The large flow tube 3 and the small flow tube 12 can be used alone or in combination. The specific method of use is as follows:

[0039] When the design flow rate of the inlet duct model is large, its outlet size is generally large. At this time, a large-sized throttling cone system is selected to adjust the outlet back pressure. For the present invention, it is only necessary to remove the small-flow cylinder 12 and use the large-flow cylinder 3 alone for testing.

[0040] like Figure 2 As shown, it is a schematic diagram of a throttling system connected to a large-size outlet inlet model. When conducting an inlet test, the end face of the large flow tube is connected to the outlet of the inlet through a flange and screws, and a motor command is input to control the rotation of the motor 1, thereby causing the large throttling cone 7 to move axially;

[0041] As the large throttle cone 7 moves forward, the flow area between the wall of the large throttle cone 7 and the large flow tube 3 decreases. According to the flow formula:

[0042] Where: m is mass flow rate; K is a constant of 0.0404; p is total pressure; T is total temperature; A is flow area; q is density function; M is Mach number. It can be seen that as the flow area A decreases, the flow rate allowed to pass is also getting smaller and smaller, and the back pressure at the inlet outlet is getting larger and larger. When the large throttle cone 7 moves forward to Figure 2 When in the middle front end position, the wall surface of the large throttling cone 7 is closed to the wall surface of the large flow tube 3. At this time, the flow rate allowed to flow is zero, and the back pressure at the inlet duct outlet reaches the maximum limit.

[0043] For motor 1, when the number of pulses given is certain, its rotation angle is constant, that is, the forward distance of the large throttle cone 7 is fixed, and the change in flow area caused by it is fixed. Ultimately, the change in inlet flow rate and outlet back pressure are fixed. When the number of pulses given by motor 1 reaches the minimum allowable value, the minimum change in back pressure regulation (that is, the regulation accuracy) of the throttle cone system is reached.

[0044] However, for the intake duct test model with a smaller design flow rate, the above-mentioned back pressure regulation accuracy may still not be suitable. The conventional practice is to directly replace it with a small throttling system. In the actual test process, it is often necessary to prepare multiple sets of throttling cone systems with different regulation accuracy to meet the test requirements, which greatly increases the test cost and test cycle. However, the throttling cone system of the present invention improves the regulation accuracy by combining the small flow cylinder 12 with the large flow cylinder 3.

[0045] like Figure 3 As shown, it is a schematic diagram of the throttling system connected to the small-sized outlet inlet duct model. It can be seen that compared with the throttling cone system used in the large-sized inlet duct test model, it is only necessary to connect the small flow tube 12 and its accessories to the front end of the large-sized throttling cone system through flanges and screws, without replacing the entire system.

[0046] At this time, under the same pulse number, the flow area change caused is smaller, and the back pressure regulation accuracy of the inlet duct outlet is higher. At the same time, through reasonable design, the minimum flow area between the outer wall of the small throttle cone 13 and the inner wall of the small flow tube 12 can always be smaller than the throttling area between the outer wall of the large throttle cone 7 and the inner wall of the large flow tube 3, so that the small throttle cone 13 always plays the role of back pressure regulation. Figure 3 As shown, when the two throttling cones (large throttling cone 7 and small throttling cone 13) move to the front end position, the small throttling cone 13 has moved to the front end so that the flow area in the flow channel is reduced to 0, while there is still a certain space between the large throttling cone 7 and the large flow cylinder 3.

[0047] The large flow cylinder 3 and the small flow cylinder 12 included in the system of the present invention are connected by flanges and screws, and the large flow cylinder 3 can be used alone or in combination. Figure 2 and Figure 3 As shown, the space between the inner wall of the flow cylinder and the outer wall of the throttling cone is the airflow area. When the throttling cone moves back and forth relative to the flow cylinder, the minimum flow area of ​​the space changes, causing the airflow rate that can flow to change, thereby changing the back pressure at the inlet outlet.

[0048] In the embodiment of the present invention, the large flow cylinder 3 and the small flow cylinder 12 are connected by flange screws. The large flow cylinder 3 can be disassembled and used alone to perform throttling at the outlet of a large-size inlet duct model. In this case, section A is the throttling inlet. The small flow cylinder 12 can also be combined to perform throttling at the outlet of a small-size inlet duct model. In this case, section B is the throttling inlet. The motor 1 and the corresponding control system are shared by the large flow cylinder 3 and the small flow cylinder 12.

[0049] In the embodiment of the present invention, the motor 1 is fixed on the motor support 2, the motor support 2 is fixed in the large flow tube 3, the motor 1 drives the large lead screw 8 to rotate through the transmission key, and then drives the large throttling cone 7 to move forward and backward along the guide rail, changing the back pressure of the A section (throttling inlet, model outlet). When the small flow tube 12 and corresponding components are installed, the large lead screw 8 drives the small lead screw 15 to rotate through the transmission key, and then drives the small throttling cone 13 to move forward and backward along the guide rail, changing the back pressure of the B section (throttling inlet, model outlet).

[0050] In this embodiment, when two flow cylinders are used in combination, since the minimum flow area between the small flow cylinder 12 and the small throttling cone 13 is smaller than the minimum flow area between the large flow cylinder 3 and the large throttling cone 7, the former plays a role in back pressure regulation. When the small throttling cone 13 is adjusted, there should be no blockage at the large throttling cone 7, so the throttling cone stroke L1>L2; the throttling inlet diameter D1 can generally be 2-4 times of D2.

[0051] The front end of the system of the present invention is a flange interface, which can be connected to the outlet of the intake duct test model. The air tightness of the connection position can be ensured by a sealing ring or applying silicone rubber; the rear end of the system can be connected to intake duct test devices such as a flow meter and an ejector.

[0052] The throttling system of the present invention is suitable for high-speed wind tunnel inlet tests. During the test, the outlet of the aircraft inlet model is connected to the throttling system, and the throttling cone is controlled by a motor to move forward and backward to change the inlet back pressure. There are a large and a small throttling cone in each of the large and small flow cylinders. For a large-size outlet inlet model, the small-flow cylinder part of the throttling system can be removed, and the model outlet is directly connected to the large-flow cylinder inlet. The large throttling cone is driven to move forward and backward by the motor to rotate the lead screw to change the model outlet back pressure; for a small-size outlet inlet model, the small-flow cylinder part of the throttling system can be added, and the model outlet is directly connected to the small-flow cylinder inlet. The small lead screw is connected to the large lead screw through a positioning key, and then the motor can rotate the two lead screws at the same time, thereby moving the large and small throttling cones forward and backward. Since the flow area of ​​the small-flow cylinder part is smaller at this time, it plays a role in actually controlling the outlet back pressure of the inlet model.

[0053] The throttle cone system of the present invention is mainly used to adjust the back pressure for different inlet test models. Its upstream is generally connected to the inlet outlet or connected to the inlet outlet through other pipelines, and its downstream can be directly exposed to the flow field or connected to other components such as flow meters and ejectors through pipelines. The size of the throttle cone system for the wind tunnel inlet test is not specified and can be adjusted according to actual needs. A variety of different sizes can also be prepared for selection. In short, everything is based on the test needs and can be modified.

[0054] The present invention can match air inlet wind tunnel test models with different outlet diameters, has a wide range of flow rate regulation capabilities and back pressure regulation capabilities, and has flow rate regulation capabilities and back pressure regulation capabilities with different precisions.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A throttle cone system for a wind tunnel inlet test with a wide adjustment range, characterized in that: It includes a large flow tube, a small flow tube, a large lead screw and a small lead screw. The front end of the large flow tube is detachably connected to the small flow tube. The two ends of the large lead screw are respectively rotatably connected to the center positions of the front end and the rear end of the large flow tube. One end of the small lead screw is fixedly connected to the large lead screw, and the other end of the small lead screw is rotatably connected to the center position of the front end surface of the small flow tube. The large lead screw is provided with a large throttling cone, and the outer side of the large throttling cone is circumferentially fixed by a large throttling cone guide rail. The small lead screw is provided with a small throttling cone, and the outer side of the small throttling cone is circumferentially fixed by a small throttling cone guide rail.

2. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 1, characterized in that: It also includes a motor, which is fixed to the downstream end of the large flow tube through a motor support, and the front end of the output shaft of the motor is connected to the large lead screw through a first transmission key.

3. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 1, characterized in that: A flange is provided on the small diameter cylindrical end surface of the large flow cylinder, and the small flow cylinder is connected to the large flow cylinder via the flange.

4. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 1, characterized in that: The outer wall thread of the large lead screw matches the inner wall thread of the central through hole of the large throttling cone, and the outer wall thread of the small lead screw matches the inner wall thread of the central through hole of the small throttling cone.

5. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 1, characterized in that: The outer shape of the large flow cylinder includes a small diameter cylindrical section, a large diameter cylindrical section and a transition section between the two cylindrical sections. When the large throttling cone moves back and forth along the axial direction, the minimum cross-sectional area between the outer wall surface of the large throttling cone and the inner wall surface of the transition section of the large flow cylinder, that is, the air flow area, changes.

6. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 5, characterized in that: The outer wall surface of the large throttling cone includes a conical section and a cylindrical section. When the interface between the conical section and the cylindrical section coincides with the small end surface of the transition section of the large flow tube, the airflow area is the smallest. When the interface between the conical section and the cylindrical section coincides with the large end surface of the transition section of the large flow tube, the airflow area is the largest.

7. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 6, characterized in that: The diameter of the straight section of the large throttling cone is the same as the diameter of the small end surface of the transition section of the large flow tube.

8. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 7, characterized in that: The small flow cylinder includes a transition section and a cylindrical section. The cylindrical section has a smaller diameter and a flange on the end face for matching the outlet end of a small-diameter inlet duct test model. The large end face diameter of the transition section is the same as the diameter of the small-diameter cylindrical section of the large flow cylinder. The transition section end face of the small flow cylinder is provided with a flange for combination with the large flow cylinder.

9. The method for using the throttle cone system for wind tunnel inlet test with a wide adjustment range according to claim 2, characterized in that: The steps include: S1. When the design flow rate of the inlet model is large, the small flow tube is removed and the large flow tube is used alone for the test; when conducting the inlet test, the end face of the large flow tube is connected to the outlet of the inlet, and the motor command is input to control the motor to rotate, thereby moving the large throttle cone axially; As the large throttle cone moves forward, the flow area between the wall of the large throttle cone and the large flow tube decreases. As the flow area decreases, the flow rate allowed to pass is also getting smaller and smaller, and the back pressure at the inlet duct outlet is getting larger and larger. When the large throttle cone moves forward to the front end position, the wall of the large throttle cone and the wall of the large flow tube are closed. At this time, the flow rate allowed to flow is zero, and the back pressure at the inlet duct outlet reaches the maximum limit. S2. Connect the small flow cylinder, small lead screw and small throttling cone to the front end of the throttling cone system. The large lead screw drives the small lead screw to rotate, and then drives the small throttling cone to move back and forth to change the cross-sectional back pressure. At this time, under the same number of pulses, the flow area change caused is smaller, and the back pressure regulation accuracy at the inlet duct outlet is higher. At the same time, the minimum flow area between the outer wall of the small throttling cone and the inner wall of the small flow cylinder is always smaller than the throttling area between the outer wall of the large throttling cone and the inner wall of the large flow cylinder, so that the small throttling cone always plays the role of back pressure regulation. When the large throttling cone and the small throttling cone move to the front end position, the small throttling cone has moved to the front end, so that the flow area in the flow channel is reduced to 0, while there is still a certain space between the large throttling cone and the large flow cylinder.

10. The method for using the throttle cone system for wind tunnel inlet test with a wide adjustment range according to claim 9, characterized in that: When the two flow cylinders are used in combination, since the minimum flow area between the small flow cylinder and the small throttling cone is smaller than the minimum flow area between the large flow cylinder and the large throttling cone, the former plays a role in back pressure regulation; when the small throttling cone is adjusted, the large throttling cone stroke L1 is greater than the small throttling cone stroke L2.

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