A wind tunnel inlet test throttle cone system with a wide adjustment range and its use method

Abstract

The present invention provides a throttle cone system for a wind tunnel inlet test with a wide adjustment range and a method for use thereof, comprising a large flow tube, the front end of the large flow tube being detachably connected to a small flow tube, the two ends of a large lead screw being rotatably connected to the center positions of the front and rear ends of the large flow tube, one end of a small lead screw being fixedly connected to the large lead screw, and the other end of the small lead screw being rotatably connected to the center position of the front end surface of the small flow tube; a large throttle cone being provided on the large lead screw, the outer side of the large throttle cone being circumferentially fixed by a large throttle cone guide; and a small throttle cone being provided on the small lead screw, the outer side of the small throttle cone being circumferentially fixed by a small throttle cone guide. The present invention is used to adjust back pressure for different inlet test models, can match inlet wind tunnel test models with different outlet diameters, has a wide range of flow adjustment capabilities and back pressure adjustment capabilities, and has flow adjustment capabilities and back pressure adjustment capabilities with different precisions.

Description

Technical Field

[0001] The present 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 primary methods for evaluating the performance of air-breathing aircraft inlets. It measures the static and dynamic aerodynamic characteristics of the inlet, including the total pressure recovery coefficient σ, flow coefficient φ, surge margin, and various types of distortion indices. This provides test data for inlet design, ensuring that inlet performance throughout the entire flight envelope meets engine requirements. Inlet testing, a throttling system is typically used to adjust the inlet outlet flow rate, thereby varying the outlet backpressure. This simulates the changes in downstream backpressure during actual flight, allowing the inlet's backpressure resistance to be evaluated, as well as performance parameters under varying backpressure conditions.

[0003] Existing inlet test throttling systems usually consist 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 the ability to adjust flow over a wide range and with high precision. 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 blocked too much, 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 will be difficult to determine due to insufficient flow regulation accuracy, making it difficult to adjust the flow and outlet back pressure under the required state, and increasing 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 with its own corresponding motor device and control system, which increases economic and maintenance costs.

[0004] The wide-adjustment-range throttle system for wind tunnel inlet tests described in this invention can be adapted to inlet models with varying outlet sizes, thereby expanding the applicability of the throttle cone system. Furthermore, the throttle cone system's flow regulation accuracy varies when using different flow cylinders, meeting the flow regulation accuracy requirements of various inlet tests. To address the issues of limited flow regulation range and insufficient flow regulation accuracy in existing inlet wind tunnel test throttle systems, a wide-adjustment-range throttle cone system for wind tunnel inlet tests and its use are needed. Summary of the Invention

[0005] The object of the present invention is to provide a throttle cone system for a wind tunnel inlet test with a wide adjustment range and a method for use thereof, which has a wide range of flow regulation capability and back pressure regulation capability; and has flow regulation capability and back pressure regulation capability 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 rotatably connected to the center position of the front end and the rear end of the large flow tube, respectively, 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 throttle cone, the outer side of which is circumferentially fixed by a large throttle cone guide rail; the small lead screw is provided with a small throttle cone, the outer side of which is circumferentially fixed by a small throttle 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 throttle cone, and the outer wall thread of the small lead screw matches the inner wall thread of the central through hole of the small throttle 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 back and forth axially, 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 airflow 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 face 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 face 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 the small-diameter inlet duct test model. The diameter of the large end face of the transition section is the same as the diameter of the small-diameter cylindrical section of the large flow cylinder. The end face of the transition section 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 throttle cone system for wind tunnel inlet testing with a wide adjustment range, comprising the following steps:

[0016] S1. When the intake model is designed for a large flow rate, remove the small flow tube and use the large flow tube alone for testing. During the intake test, connect the end face of the large flow tube to the intake outlet, input motor commands to control the motor rotation, and thus move 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 through also becomes smaller and smaller, and the back pressure at the inlet duct outlet becomes larger and larger. When the large throttle cone moves forward to the front position, the wall of the large throttle cone and the wall of the large flow tube close together. At this time, the flow rate allowed to flow through is zero, and the back pressure at the inlet duct outlet reaches its maximum value.

[0018] S2. Connect the small flow cylinder, small screw and small throttle cone to the front end of the throttle cone system. The large screw drives the small screw to rotate, and then drives the small throttle cone to move back and forth, changing 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 outlet is higher. At the same time, the minimum flow area between the outer wall of the small throttle cone and the inner wall of the small flow cylinder is always smaller than the throttling area between the outer wall of the large throttle cone and the inner wall of the large flow cylinder, so that the small throttle cone always plays the role of back pressure regulation. When the large throttle cone and the small throttle cone move to the front end position, the small throttle 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 throttle 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 this invention is used to regulate backpressure for various inlet test models. Its upstream connection is typically connected to the inlet outlet or via other piping, while its downstream connection can be directly exposed to the flow field or connected via piping to other components such as a flow meter and ejector. This solution can accommodate inlet wind tunnel test models with varying outlet diameters, providing a wide range of flow and backpressure regulation capabilities, as well as varying degrees of accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Figure 1 Schematic diagram of the overall structure of an embodiment of the present invention;

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

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

[0025] In the figure: 1. Motor; 2. Motor support; 3. Large flow cylinder; 4. Large throttle cone guide; 5. First transmission key; 6. First bearing; 7. Large throttle cone; 8. Large screw; 9. Second bearing; 10. Second transmission key; 11. Small throttle cone guide; 12. Small flow cylinder; 13. Small throttle cone; 14. Third bearing; 15. Small screw. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts 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 to indicate directions or positional relationships based on the directions 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 device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said 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 an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the 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 includes a motor 1, a motor support 2, a large flow tube 3, a large throttle cone guide 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 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 cylinder 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 motion 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 cylinder 3 through the first bearing 6, so that it is fixed in the radial direction; 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 rail 4; under this structure, when the motor 1 rotates, the circumferential motion of the motor shaft can be converted into axial motion of the large throttling cone 7.

[0033] The large flow tube 3 is divided into three sections: a small-diameter cylindrical section, a large-diameter cylindrical section, and a transition section between the two cylindrical sections. As the large throttle cone 7 moves axially back and forth, the minimum cross-sectional area (i.e., the airflow area) between the outer wall of the large throttle cone 7 and the inner wall of the transition section of the flow tube changes. A flange is provided on the small-diameter cylindrical end face of the large flow tube 3 to facilitate connection with the small flow tube 12.

[0034] At the same time, the outer wall of the large throttle 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 minimized. 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 maximized. Typically, the diameter of the straight section of the large throttle 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 busbar of the large throttle cone 7 and the transition busbar of the large flow tube 3 can be designed as a straight line or other curved shape.

[0035] The end of the large lead screw 8 is fixed at the center of the front end surface of the large flow cylinder 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 threads of small lead screw 15 and the inner threads of the central through hole of small throttle cone 13 cooperate to connect the two components. A small throttle cone guide 11 is provided on the outside of small throttle cone 13 to fix it circumferentially, converting the circumferential motion transmitted from the front of motor 1 into axial motion of small throttle cone 13. The end of small lead screw 15 is fixed to the cylindrical front end surface of small flow cylinder 12 via a 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 throttle 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 also large. At this time, a large-sized throttle 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 Figure 2 shows a schematic diagram of a throttling system connected to a large-size outlet inlet model. During an inlet test, the end face of the large flow tube is connected to the inlet outlet via a flange and screws. Motor commands are input to control the rotation of 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 the mass flow rate; K is a constant of 0.0404; p is the total pressure; T is the total temperature; A is the flow area; q is the density function; M is the Mach number. It can be seen that as the flow area A decreases, the flow rate allowed to pass through becomes smaller and smaller, and the back pressure at the inlet outlet becomes 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 throttle 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 is fixed. When the number of pulses given by motor 1 reaches the minimum allowable value, the minimum change in back pressure regulation of the throttle cone system (that is, the regulation accuracy) is reached.

[0044] However, for the intake duct test model with a smaller design flow rate, the above-mentioned back pressure adjustment accuracy may still be inappropriate. 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 adjustment 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 adjustment 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 cylinder 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 at the inlet 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, thereby ensuring 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. 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 throttle cone is the airflow area. When the throttle 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 an 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 which 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 which 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 this embodiment of the present invention, motor 1 is fixed to motor support 2, which is fixed within large flow cylinder 3. Motor 1 drives large lead screw 8 via a transmission key, which in turn drives large throttle cone 7 to move back and forth along a guide rail, changing the back pressure at section A (throttle inlet, mold outlet). When small flow cylinder 12 and corresponding components are installed, large lead screw 8 drives small lead screw 15 via a transmission key, which in turn drives small throttle cone 13 to move back and forth along the guide rail, changing the back pressure at section B (throttle inlet, mold outlet).

[0050] In this embodiment, when two flow cylinders are used in combination, the minimum flow area between the small flow cylinder 12 and the small throttle cone 13 is smaller than the minimum flow area between the large flow cylinder 3 and the large throttle cone 7. Therefore, the small throttle cone 12 performs the backpressure regulation function. When the small throttle cone 13 is adjusted, congestion should not occur at the large throttle cone 7. Therefore, the throttle cone stroke L1>L2; the throttle inlet diameter D1 can generally be 2-4 times 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 back end of the system can be connected to intake duct test devices such as flow meters and ejectors.

[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 a motor is used to control the throttling cone to move back and forth to change the inlet back pressure. There is a large throttling cone and a small throttling cone in each of the large and small flow cylinders. For a large-sized 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 back and forth by the motor to rotate the screw to change the model outlet back pressure; for a small-sized 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 screw is connected to the large screw through a positioning key, and then the motor can rotate the two sections of the screw at the same time, thereby moving the large and small throttling cones back and forth. 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 this invention is primarily used to regulate backpressure for various inlet test models. Its upstream connection is typically connected to the inlet outlet or via other piping. Its downstream connection can be directly exposed to the flow field or connected via piping to other components such as a flow meter and ejector. The dimensions of this wind tunnel inlet test throttle cone system are not specified and can be adjusted based on actual needs. Multiple sizes are available for selection. In short, everything depends on the test requirements and can be modified.

[0054] The present invention can match inlet duct wind tunnel test models with different outlet diameters, 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.

[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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above 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 wind tunnel inlet test with a wide adjustment range, characterized in that: The cam is provided with 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 and the small flow tube are detachably connected. The two ends of the large lead screw are rotatably connected to the center position of the front end and the rear end of the large flow tube respectively. 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. A large throttling cone is provided on the large lead screw, and the outer side of the large throttling cone is circumferentially fixed by a large throttling cone guide rail. A small throttling cone is provided on the small lead screw, and the outer side of the small throttling cone is circumferentially fixed by a small throttling cone guide rail. fixed in the direction; 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 airflow area changes; 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 face of the transition section of the large flow cylinder, the airflow area is the smallest; when the interface between the conical section and the cylindrical section coincides with the large end face of the transition section of the large flow cylinder, the airflow area is the largest.

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 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 throttle cone, and the outer wall thread of the small lead screw matches the inner wall thread of the central through hole of the small throttle cone.

5. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 1, 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.

6. The throttle cone system for wind tunnel inlet test with wide adjustment range according to claim 5, characterized in that: The small flow cylinder includes a transition section and a cylindrical section. The cylindrical section has a small diameter and a flange on the end face, which is used to match the outlet end of the small-diameter air inlet test model. The diameter of the large end face of the transition section is the same as the diameter of the small-diameter cylindrical section of the large flow cylinder. The end face of the transition section of the small flow cylinder is provided with a flange, which is used to be combined with the large flow cylinder.

7. 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 intake model is designed for a large flow rate, remove the small flow tube and use the large flow tube alone for testing. During the intake test, connect the end face of the large flow tube to the intake outlet, input motor commands to control the motor rotation, and thus move 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 through also becomes smaller and smaller, and the back pressure at the inlet duct outlet becomes larger and larger. When the large throttle cone moves forward to the front position, the wall of the large throttle cone and the wall of the large flow tube close together. At this time, the flow rate allowed to flow through is zero, and the back pressure at the inlet duct outlet reaches its maximum value. S2. Connect the small flow cylinder, small screw and small throttle cone to the front end of the throttle cone system. The large screw drives the small screw to rotate, and then drives the small throttle cone to move back and forth, changing 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 outlet is higher. At the same time, the minimum flow area between the outer wall of the small throttle cone and the inner wall of the small flow cylinder is always smaller than the throttling area between the outer wall of the large throttle cone and the inner wall of the large flow cylinder, so that the small throttle cone always plays the role of back pressure regulation. When the large throttle cone and the small throttle cone move to the front end position, the small throttle cone has moved to the front end, so that the flow area in the flow channel is reduced to 0, while there is still space between the large throttle cone and the large flow cylinder.

8. The method for using the throttle cone system for wind tunnel inlet test with a wide adjustment range according to claim 7, 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.

Images