A space engine test plume pressure measurement system

Abstract

The present invention relates to the field of space engine ground test technology, and provides a space engine test plume pressure measurement system, which at least includes: a pressure differential sensor, wherein the body of the pressure differential sensor is provided with a measuring end interface, a reference end interface, and a back pressure interface; a measuring end air duct, one end of which is connected to the measuring end interface, and the other end is suitable for being arranged at a pressure measuring point in the space engine plume field; a reference end air duct, one end of which is connected to the reference end interface, and the other end of which is connected to the back pressure interface; wherein the back pressure interface includes at least two gas channels of different inner diameters along the gas delivery direction, so that the gas pressure at the reference end interface remains constant within a preset time period in the test. This measurement system simplifies the system, eliminates the need to set a back pressure zone, eliminates the device for measuring the pressure value at the reference end interface, shortens the length of the reference end air duct, greatly reduces the workload on site, and can meet measurement requirements at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of space engine ground testing, and in particular to a space engine test plume pressure measurement system. Background Art

[0002] Space engines are commonly used in spacecraft such as rockets and satellites. When an engine ignites in a vacuum environment, a vacuum plume forms at the nozzle that expands freely into the surrounding environment. This vacuum plume impacts the surface of the spacecraft within the plume field, causing mechanical, thermal, and surface contamination effects. This temporary, localized increase in pressure within the plume field can damage the surface properties of the spacecraft or scientific instruments, shortening its lifespan or even causing it to fail.

[0003] Conventional plume pressure measurement devices for space engine tests involve opening a hole in the side panel at the pressure measurement point, installing a pressure-measuring air tube. The other end of the tube is connected via a flexible hose to a micro-differential pressure transmitter, which measures the surface pressure of the plume impacting the flat plate. In use, the sensor leads to two pressure tubes: one end is connected to the measured gas introduced by the aerodynamic measurement plate, and the other end is connected to the backpressure area. The difference between the pressure at the pressure-measuring end and the pressure in the backpressure area is the pressure at that location.

[0004] However, the measuring device is relatively complicated. In addition to installing the gas guide device and sensor at the pressure end to be measured in the vacuum chamber, it is also necessary to arrange the back pressure area and lay a longer pressure measuring pipe or specially set up an electric valve to control the pressure stability of the back pressure area. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that the space engine test plume pressure measurement device is relatively complicated. In addition to installing the air guide device and sensor at the pressure end to be measured in the vacuum chamber, it is also necessary to arrange the back pressure area, lay a longer pressure measuring pipe or specially set up an electric valve to control the pressure stability of the back pressure area, thereby providing a space engine test plume pressure measurement system.

[0006] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0007] A space engine test plume pressure measurement system comprises at least: a differential pressure sensor, the body of the differential pressure sensor being provided with a measuring end interface, a reference end interface and a back pressure interface; a measuring end air duct, one end of which is connected to the measuring end interface, and the other end is suitable for being arranged at a pressure measuring point in the space engine plume field, so that the gas in the space engine plume field can enter the interior of the differential pressure sensor; a reference end air duct, one end of which is connected to the reference end interface, and the other end is connected to the back pressure interface, so that the gas entering the interior of the differential pressure sensor can flow from the back pressure interface to the reference end interface; wherein the back pressure interface comprises at least two gas channels with different inner diameters along the gas delivery direction, so that the gas pressure at the reference end interface remains constant within a preset time period in the test.

[0008] Furthermore, the back pressure interface is a tubular structure, and the tube body structure of the back pressure interface includes a plurality of segments with different outer diameters along the gas conveying direction; each of the segments is provided with at least one gas channel.

[0009] Furthermore, when a plurality of the gas channels are included in the same segment, the inner diameters of two adjacent gas channels are different.

[0010] Furthermore, the space engine test plume pressure measurement system also includes a vacuum chamber, and the space engine and the pressure difference sensor are both arranged in the vacuum chamber.

[0011] Furthermore, the space engine test plume pressure measurement system also includes a power supply cable, a power supply and a first terminal; the first terminal is arranged on the pressure differential sensor, one end of the power supply cable is connected to the first terminal located inside the vacuum chamber, and the other end is connected to the power supply located outside the vacuum chamber.

[0012] Furthermore, the space engine test plume pressure measurement system also includes a signal cable, a data acquisition device and a second terminal; the second terminal is arranged on the pressure differential sensor, one end of the signal cable is connected to the second terminal located inside the vacuum chamber, and the other end is connected to the data acquisition device located outside the vacuum chamber.

[0013] Furthermore, the measuring end air duct and the reference end air duct are both hoses made of non-metallic materials.

[0014] Furthermore, the measuring end interface, the reference end interface and the back pressure interface are all hard tubes made of metal.

[0015] The technical solution of the present invention has the following advantages:

[0016] The space engine test plume pressure measurement system provided by the present invention, by providing a variable diameter back pressure interface on the pressure differential sensor, prevents gas from filling the reference end air duct through the back pressure interface in a short time, thereby ensuring that the pressure value at the reference end interface of the pressure differential sensor is constant during the test process. The difference between the pressure value measured at the measuring end interface and the pressure value in the vacuum chamber is the pressure value at the pressure measuring point in the space engine plume field. Compared with the measurement device in the prior art, the system is simplified, no back pressure zone is required, the device for measuring the pressure value at the reference end interface is eliminated, the length of the reference end air duct is shortened, and the workload on site is greatly reduced while meeting the measurement requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 Schematic diagram of a space engine test plume pressure measurement system according to an embodiment of the present invention;

[0019] Figure 2 Schematic diagram of a differential pressure sensor in a plume pressure measurement system for a space engine test according to an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a reference end air duct in a space engine test plume pressure measurement system according to an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of a reference end air duct in a space engine test plume pressure measurement system in another embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of a differential pressure sensor in a space engine test plume pressure measurement system according to an embodiment of the present invention using a three-way interface instead of a reference end interface;

[0023] Figure 6 for Figure 5 The pressure change curve at the three-way interface in .

[0024] 1. Differential pressure sensor; 2. Measuring end interface; 3. Reference end interface; 4. Back pressure interface; 5. Measuring end air duct; 6. Reference end air duct; 7. Segment; 8. Gas channel; 9. T-joint interface; 10. Vacuum pressure sensor; 11. Power supply; 12. Data acquisition equipment; 13. Power supply cable; 14. Signal cable; 15. Engine; 16. Vacuum chamber. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0028] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] like Figure 1 、 Figure 2 As shown, this embodiment provides a space engine test plume pressure measurement system, including: a vacuum chamber 16, a pressure difference sensor 1, a measuring end air duct 5, a reference end air duct 6, a power supply cable 13, a signal cable 14, a power supply 11 and a data acquisition device 12.

[0030] Among them, the differential pressure sensor 1, the measuring end air duct 5 and the reference end air duct 6 are all located in the vacuum chamber 16, the power supply 11 and the data acquisition device 12 are located outside the vacuum chamber 16, and the power supply cable 13 and the signal cable 14 pass through the vacuum chamber 16.

[0031] The differential pressure sensor 1 includes a body and a measuring end interface 2, a reference end interface 3, a back pressure interface 4 and wiring terminals arranged on the body.

[0032] For example, the body of the differential pressure sensor 1 includes an internal pressure measuring core, a signal conditioning circuit board, and an external shell, and the shell is used to protect the internal pressure measuring core and the signal conditioning circuit board.

[0033] For example, the measuring end interface 2 is used to connect the measuring end gas guide tube 5 . The measuring end interface 2 can be a metal tube installed on the surface of the body to ensure that the measuring end gas can enter the body through the measuring end interface 2 .

[0034] For example, the reference end interface 3 is used to connect the reference end air guide tube 6. The reference end interface 3 can be a metal tube installed on the surface of the body.

[0035] For example, the back pressure interface 4 is used to connect the reference end air guide tube 6. The back pressure interface 4 can be a metal tube. A hole can be punched on the body of the sensor first, and then the back pressure interface 4 can be installed on the surface of the body of the sensor.

[0036] For example, the measuring end interface 2 and the reference end interface 3 may both be located on the top surface of the differential pressure sensor 1 , and the back pressure interface 4 may be located on the right side surface of the differential pressure sensor 1 .

[0037] like Figure 3 、 Figure 4 As shown, specifically, the pipe body of the back pressure interface 4 may include multiple segments 7 with different outer diameters. For example, the back pressure interface 4 may be formed by alternately connecting segments 7 with two outer diameters.

[0038] For example, each segment 7 is provided with at least one gas channel 8, and the gas channels 8 in two adjacent segments 7 are interconnected. For example, when two or more gas channels 8 with different inner diameters are provided in the same segment 7, the two or more gas channels 8 with different inner diameters can be arranged alternately. The size of the gas channels 8 can be designed as needed to prevent gas from quickly filling the reference end gas conduit 6 through the back pressure interface 4 and then reaching the reference end interface 3 through the reference end gas conduit 6, thereby ensuring that the pressure value at the reference end interface 3 remains constant during the test.

[0039] For example, the measuring end air duct 5 can be a non-metallic hose, one end of which is positioned at a pressure measurement point within the engine plume field, and the other end is connected to the measuring end interface 2 of the differential pressure sensor 1. Gas at the pressure measurement point within the engine 15 plume field can reach the measuring end interface 2 through the measuring end air duct 5. Preferably, the measuring end air duct 5 is sleeved onto the outside of the measuring end interface 2, and the connection is sealed.

[0040] For example, the reference end air guide tube 6 can be a non-metallic hose, one end of which is connected to the reference end interface 3 of the differential pressure sensor 1, and the other end is connected to the back pressure interface 4. Preferably, the two ends of the reference end air guide tube 6 are respectively sleeved and installed outside the reference end interface 3 and the back pressure interface 4, and the connection is sealed.

[0041] For example, the connection terminals may include a first connection terminal for connecting to the power source 11 and a second connection terminal for connecting to the data acquisition device 12 .

[0042] For example, one end of the power supply cable 13 is connected to the power source 11 , and the other end is connected to the first terminal of the differential pressure sensor 1 to supply power to the differential pressure sensor 1 and ensure normal operation of the differential pressure sensor 1 .

[0043] For example, one end of the signal cable 14 is connected to the second terminal of the differential pressure sensor 1 , and the other end is connected to the data acquisition device 12 , so as to transmit the measurement result of the differential pressure sensor 1 to the data acquisition device 12 .

[0044] Before the test, the vacuum chamber 16 is evacuated. Since the evacuation time is very long, the pressures of the differential pressure sensor 1, the measuring end air duct 5 and the reference end air duct 6 continue to drop and are all consistent with the pressure of the vacuum chamber 16. At this time, the pressure value in the vacuum chamber 16 is P0 (predetermined by the test input conditions and can be monitored in real time during the evacuation process), the pressure value at the measuring end interface 2 of the differential pressure sensor 1 is also P0, the pressure value at the reference end interface 3 of the differential pressure sensor 1 is also P0, and the pressure value at the back pressure interface 4 is also P0.

[0045] During the test phase, the engine 15 is ignited to form a plume, and the measuring end air duct 5 is arranged at a measuring point in the plume field of the engine 15. The engine plume pressure diffuses through the measuring end air duct 5 to the measuring end interface 2 of the differential pressure sensor 1, and the measuring end pressure value P1 is obtained from the main body of the differential pressure sensor 1.

[0046] Since the volume of the vacuum chamber 16 is usually 50m 3As mentioned above, the ignition time of solid engine 15 is typically less than 1 second, and the effective measurement time is also less than 1 second. Therefore, the pressure value P0 within vacuum chamber 16 will not rise rapidly within 1 second. Furthermore, due to the variable inner diameter of backpressure interface 4, when the two inner diameters before and after the variable diameter reach a certain ratio, the gas flow rate will be greatly slowed. At this time, the gas cannot reach reference end interface 3 in a short time, and the pressure value P0 at measurement end interface 2 will not change in a short time. Therefore, the engine plume pressure value ΔP at this measuring point is = P1 - P0, which can be used to accurately determine the pressure change at the measuring point.

[0047] The space engine test plume pressure measurement system provided in this embodiment, by setting a variable diameter back pressure interface 4 on the pressure differential sensor 1, prevents gas from filling the reference end air duct 6 through the back pressure interface 4 in a short time, ensuring that the pressure value at the reference end interface 3 of the pressure differential sensor 1 is constant during the test process. The difference between the pressure value measured at the measuring end interface 2 and the pressure value in the vacuum chamber 16 is the pressure value at the pressure measuring point in the space engine plume field. Compared with the measurement device in the prior art, the system is simplified, there is no need to set a back pressure zone, and the device for measuring the pressure value at the reference end interface 3 is eliminated. Only a shorter reference end air duct 6 is needed to connect the reference end interface 3 with the back pressure interface 4, shortening the length of the reference end air duct 6, greatly reducing the workload on site, and meeting the measurement requirements.

[0048] The following is a method for verifying that the pressure value at the reference end interface 3 can remain constant during a preset time period during a test.

[0049] like Figure 5 As shown, the reference end interface 3 is removed and transformed into a three-way interface 9, that is, the three-way interface 9 replaces the original reference end interface 3.

[0050] Specifically, the three-way interface 9 is installed on the surface of the sensor body, and is used to connect the reference end airway 6 and the vacuum pressure sensor 10; wherein, the vacuum pressure sensor 10 is used to monitor the pressure change at the three-way interface 9.

[0051] During a certain test, the pressure change at the three-way interface 9 is as follows Figure 6 As shown, the average pressure change in the first 1 second is 0.045Pa.

[0052] According to the Q / mT57-2012 "Liquid Rocket Engine Test System Inspection, Maintenance and Management Requirements" of the Sixth Academy of China Aerospace Science and Technology Corporation, under low-pressure conditions, if the pressure change meets ΔP≤0.05MPa / 10min, that is, 8.333Pa / s, within the specified time, the system sealing performance is good.

[0053] Based on this, it can be concluded that the pressure value P2 at the three-way interface 9 changes much less than 8.333 Pa / s, and P2 is considered to be a constant value.

[0054] Since the pressure value of P2 does not change within 1 second of ignition, and the pressure value at time 0 is P0, it can be obtained that P2=P0. Therefore, it is considered that the pressure at the reference end interface 3 can be used as the measurement reference of the differential pressure sensor 1.

[0055] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A space engine test plume pressure measurement system, characterized in that: At least: A differential pressure sensor, wherein the body of the differential pressure sensor is provided with a measuring end interface, a reference end interface and a back pressure interface; a measuring end air guide tube, one end of which is connected to the measuring end interface, and the other end of which is suitable for being arranged at a pressure measuring point in the space engine plume field, so that the gas in the space engine plume field can enter the interior of the differential pressure sensor; a reference end air guide tube, one end of which is connected to the reference end interface and the other end of which is connected to the back pressure interface, so that the gas entering the differential pressure sensor can flow from the back pressure interface to the reference end interface; Wherein, the back pressure interface includes at least two gas channels with different inner diameters along the gas delivery direction, so that the gas pressure at the reference end interface remains constant within a preset time period in the test.

2. The space engine test plume pressure measurement system according to claim 1, characterized in that: The back pressure interface is a tubular structure, and the tubular structure of the back pressure interface includes a plurality of segments with different outer diameters along the gas delivery direction; At least one gas channel is provided in each of the segments.

3. The space engine test plume pressure measurement system according to claim 2, characterized in that: When the same segment includes a plurality of the gas channels, the inner diameters of two adjacent gas channels are different.

4. The space engine test plume pressure measurement system according to claim 1, characterized in that: It also includes a vacuum chamber, in which the space engine and the pressure difference sensor are both arranged.

5. The space engine test plume pressure measurement system according to claim 4, characterized in that: Also included are a power supply cable, a power supply, and a first terminal; The first wiring terminal is provided on the pressure difference sensor. One end of the power supply cable is connected to the first wiring terminal located inside the vacuum chamber, and the other end is connected to a power source located outside the vacuum chamber.

6. The space engine test plume pressure measurement system according to claim 4, characterized in that: Also included are a signal cable, a data acquisition device, and a second wiring terminal; The second wiring terminal is provided on the pressure difference sensor, one end of the signal cable is connected to the second wiring terminal located inside the vacuum chamber, and the other end is connected to a data acquisition device located outside the vacuum chamber.

7. The space engine test plume pressure measurement system according to claim 1, characterized in that: The measuring end air guide tube and the reference end air guide tube are both hoses made of non-metallic materials.

8. The space engine test plume pressure measurement system according to claim 1, characterized in that: The measuring end interface, the reference end interface and the back pressure interface are all hard tubes made of metal materials.

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