A supersonic engine test bench and test method thereof

Abstract

A supersonic engine test bench includes an air intake system, an engine thrust measurement bench, an exhaust system, a silencer, and a high-altitude simulation cabin. The high-altitude simulation cabin is a sealed shell structure, the engine thrust measurement bench is fixedly installed in the high-altitude simulation cabin, and the test engine is installed on the engine thrust measurement bench. One end of the exhaust system passes through the shell surface of the high-altitude simulation cabin and is fixedly installed inside the high-altitude simulation cabin, and the other end is fixedly connected to the silencer. The invented supersonic engine test bench can simulate the supersonic intake state of the supersonic engine during supersonic engine and engine ground tests. At the same time, its engine thrust measurement bench can measure engine thrust and has a simple structure. In addition, the silencer reduces the number of silencer plates used while ensuring the silencer capability, occupies a small area, has a wide range of applications, and also significantly reduces costs.

Description

Technical Field

[0001] The present invention relates to the technical field of engine testing, in particular to a supersonic engine test bench and a testing method thereof. Background Art

[0002] Engine testing and measurement technology is an important part of solid propulsion technology. Before conducting flight tests, aircraft engines need to undergo high-altitude simulation tests on the ground. During engine testing, a set of intake parameters, including total intake pressure, intake air flow, intake oxygen content, total intake temperature, and engine fuel supply, are required, which are called intake state points. After reaching the set value and stabilizing, the performance and parameters are recorded or the performance is evaluated. As engines become more mature, the application of supersonic engines is becoming more and more extensive. On this basis, the engine intake system needs to simulate the supersonic intake state of supersonic engines used in aircraft, especially drones, and during engine ground tests. Existing engine test bench technology does not have mature technology for supersonic engine intake simulation, and there is no accurate theoretical judgment method for when the simulated state reaches a stable state. This leads to poor test simulation results, long test cycles, high costs, and serious waste of resources.

[0003] At the same time, thrust measurement is a key parameter that must be measured during engine testing and testing. Studying engine thrust requires numerous repeated tests, which are impossible to perform during flight testing. The main reasons are that flight testing is costly, time-consuming, yields little information, is risky, and requires significant manpower. This necessitates engine ground testing. Ground testing involves statically testing a system on the ground under specific conditions and environmental requirements to obtain information describing various system performance indicators, thereby addressing key issues in the engine thrust testing process. However, existing technology lacks mature technology for engine thrust testing equipment.

[0004] Furthermore, the primary source of noise pollution in engine test bench workplaces and the surrounding environment comes from aerodynamic noise. This noise source, present only during test bench testing, is generated by high-pressure, high-speed, high-temperature compressed air and fuel gas flowing through metal or other enclosures or being released into the atmosphere, generating noise levels exceeding 130 dB(A). Noise is unwanted sound. The human ear can hear sounds with frequencies between 20 Hz and 20,000 Hz, which are directly perceptible to humans. Noise outside this frequency range is inaudible and a silent killer, making it a target for noise control. Currently, different countries regulate noise control within different sound pressure levels based on their specific environments. According to China's Environmental Protection Law, the permitted noise pressure level for newly built enterprises operating eight hours per day is 85 dB(A), and for one hour per day, it is 94 dB(A). For engine test benches, where the sound power exceeds 130 dB(A), the duration of the noise is short, and the workplace is located far from towns and residential areas, the primary goal of noise control is to ensure that noise levels within test bench personnel meet regulatory standards and minimize noise impacts on the environment outside the test bench.

[0005] As for the method of silencing and reducing the noise generated by the test bench, there is no mature and effective technical means in the prior art. The applicant previously applied for CN203910262U, proposing a muffler, which has a certain effect on the silencing and noise reduction of the test bench. However, the staggered arrangement of the thick sheet components and thin sheet components of the muffler requires a large floor space. On the one hand, when the exhaust flow of the engine test bench is small, in order to ensure the quality of silence, it is still necessary to establish multiple thick sheet components and thin sheet components (each layer of silencer sheet components requires at least 2 thick sheet components of silencers and 2 thin sheet components of silencers, plus a thick sheet component of a half-sheet muffler and a thin sheet component of a half-sheet muffler), which leads to a significant increase in cost; on the other hand, when the floor area of ​​the engine test bench where the silencer equipment is allowed to be installed is small and does not allow the staggered arrangement of thick sheet components and thin sheet components of the muffler as described in the patent application on each layer, removing any silencer sheet will lead to a decrease in the silencer ability. Summary of the Invention

[0006] The technical problem solved by the present invention is to overcome the deficiencies of the prior art and provide a supersonic engine test bench and a test method thereof.

[0007] The technical solution of the present invention is: a supersonic engine test bench, including an air intake system, an engine thrust measurement bench, an exhaust system, a silencer and a high-altitude simulation cabin; the high-altitude simulation cabin is a sealed shell structure, the engine thrust measurement bench is fixedly installed in the high-altitude simulation cabin, and the test engine is installed on the engine thrust measurement bench; the air intake system is connected to the test engine or the exhaust system, one end of the exhaust system passes through the shell surface of the high-altitude simulation cabin and is fixedly installed inside the high-altitude simulation cabin, and the other end is fixedly connected to the silencer.

[0008] The advantages of the present invention compared with the prior art are:

[0009] 1. The supersonic engine test bench and test method of the present invention are characterized in that a Laval-type supersonic nozzle is provided in the air intake system between the temperature simulation unit and the engine air intake, so as to realize supersonic engine and engine ground test, supersonic air intake state simulation of the supersonic engine, and the engine air intake flow rate and total air intake pressure are simulated by the engine air intake source. At the same time, oxygen is supplemented for the engine air intake by the oxygen supply source, and the engine air intake temperature is simulated by the temperature simulation unit, thereby realizing a true simulation of the engine air intake with high simulation accuracy; an alcohol supply source is provided, and the alcohol is ignited by the igniter to generate heat, which is heat-exchanged with the engine air intake in the temperature simulation unit, thereby realizing the regulation of the engine air intake temperature; the fuel supply to the engine is realized by the fuel supply source; and the flow rate and pressure of the relevant supply sources are adjusted by arranging various valves, thereby realizing the simulation of multiple state points.

[0010] 2. The supersonic engine test bench and test method of the present invention place the test engine in a simulation cabin, which is sealed. Air is extracted through an exhaust ejector to simulate the environmental pressure of the engine at different flight altitudes. The exhaust ejector is provided with an ejection airflow by an active airflow supply source of the ejector. The method is simple; fuel is supplied to the engine through a fuel supply source.

[0011] 3. The supersonic engine test bench and test method thereof of the present invention realizes the measurement of engine thrust and has a simple structure.

[0012] 4. The supersonic engine test bench and test method of the present invention, wherein the engine thrust measurement bench cleverly suspends the moving frame on the fixed frame via spring sheets and uses a force sensor to measure the engine thrust, is simple and easy to operate.

[0013] 5. In the supersonic engine test bench and test method of the present invention, a measuring section bracket is provided in the engine thrust measurement bench to ensure that the measuring section used to measure the intake parameters of the test engine is coaxial with the engine, thereby ensuring the accuracy of the engine intake simulation and improving the accuracy of the engine intake parameter measurement.

[0014] 6. In the supersonic engine test bench and test method thereof of the present invention, the overall rigidity of the dynamic frame of the engine thrust measurement bench is relatively large. To ensure the dynamic performance of the test bench, the load-bearing elements are rationally distributed in the design, the principle of equal structural strength is adopted, and the non-stressed parts of the material are removed to optimize the design and reduce the mass of the dynamic frame.

[0015] 7. In the supersonic engine test bench and test method thereof of the present invention, a horizontal base is provided on the fixed frame of the engine thrust measurement bench to improve the bearing capacity of the entire fixed frame.

[0016] 8. In the supersonic engine test bench and test method of the present invention, a locking state is provided in the engine thrust measurement bench so that the movable frame and the fixed frame remain in a fixed state when the engine is not tested or when the engine is installed before a test. This extends the service life of the engine thrust measurement bench and avoids applying irreversible external forces to the spring sheets or even causing damage to the spring sheets when the engine and related test pieces are installed in the movable frame in its own state (not in the locking state), thereby ensuring the accuracy of the engine thrust measurement bench.

[0017] 9. The supersonic engine test bench and test method of the present invention adopt a gantry-type engine mounting frame in the engine thrust measurement bench to suspend the engine, thereby improving the measurement accuracy of the engine thrust. The front and rear joints are adjustable, which greatly expands the applicability of the engine mounting frame and solves the problem of having one engine mounting frame for each engine in the past.

[0018] 10. In the supersonic engine test bench and test method of the present invention, a standard force sensor is used in the engine thrust measurement bench to determine the error of the working force sensor and statically calibrate it, thereby generating a set of high-precision known "simulated thrusts" to calibrate the force measurement system. Because it reproduces the deformation and force conditions of the test state, it eliminates most of the system errors caused by deformation, installation, temperature, constraints, etc. during the test, thereby reducing the uncertainty of thrust measurement.

[0019] 11. In the supersonic engine test bench and test method of the present invention, the characteristic curve diagrams of the standard force sensor and the working force sensor are calibrated and drawn in the engine thrust measurement bench, and the force value output by the working force sensor is accurately determined by the characteristic curve diagram to determine the actual value of the force, thereby avoiding the calibration of the working force sensor for each test, with low cost and high efficiency.

[0020] 12. The supersonic engine test bench and test method of the present invention, the silencer device of which creatively proposes a thin and thick combination silencer flat sheet, realizes that thin silencer sheets and thick silencer sheets are respectively set on two sides of an air flow channel. Under the premise of ensuring the silencer ability, the number of silencer sheets used is reduced (according to the prior art, each layer of silencer sheet assembly requires at least 2 thick sheet assemblies of silencers and 2 thin sheet assemblies of silencers, plus a thick sheet assembly of half a silencer and a thin sheet assembly of half a silencer. The silencer sheet assembly proposed by the present invention is equivalent to only 1 thick sheet assembly of silencer and 1 thin sheet assembly of silencer, plus a thick sheet assembly of half a silencer and a thin sheet assembly of half a silencer), occupies a small area (applicable to large flow test benches as well as small flow engine test benches), has a wide range of applications, and also greatly reduces costs.

[0021] 13. The supersonic engine test bench and test method of the present invention have a silencer device that guides the gas entering the variable frequency diffuser cylinder by setting a conical variable frequency diffuser guide cone, so that the gas entering the variable frequency diffuser cylinder is evenly discharged from a plurality of variable frequency diffuser outlet holes, which is convenient for subsequent silencer and improves the silencer effect.

[0022] 14. The supersonic engine test bench and test method of the present invention have a silencer device which is provided with a variable frequency diffuser, and a variable frequency diffuser outlet hole in the form of a through hole is provided on the surface of the variable frequency diffuser. The airflow passes through the variable frequency diffuser outlet hole to shift the noise frequency to a high frequency, thereby reducing the difficulty of noise control by utilizing the principle that high frequencies are easier to silence than low frequencies.

[0023] 15. The supersonic engine test bench and test method of the present invention has a muffler device with a guide plate on the muffler plate to guide the gas entering the air flow channel, making the gas flow uniform and further improving the muffler effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the supersonic engine test bench of the present invention.

[0025] Figure 2 This is a structural front view of the engine thrust measurement bench in the supersonic engine test bench of the present invention.

[0026] Figure 3 for Figure 2 Magnified view of part A in the middle.

[0027] Figure 4 for Figure 2 Magnified view of part B in the middle.

[0028] Figure 5 This is a top view of the engine thrust measurement bench structure in the supersonic engine test bench of the present invention.

[0029] Figure 6 for Figure 5 Magnified view of middle C.

[0030] Figure 7 The diagram is a structural diagram of the measuring section bracket of the engine thrust measurement bench in the supersonic engine test bench of the present invention.

[0031] Figure 8 for Figure 7 Magnified view of section D in the middle.

[0032] Figure 9 for Figure 7 Magnified view of middle E.

[0033] Figure 10 This is a structural front view of the engine mounting frame of the engine thrust measurement bench in the supersonic engine test bench of the present invention.

[0034] Figure 11 The figure is a side view of the structure of the engine mounting frame of the engine thrust measurement bench in the center of the supersonic engine test bench of the present invention.

[0035] Figure 12 The figure is a schematic structural diagram of the engine mounting top frame of the engine thrust measurement bench in the supersonic engine test bench of the present invention.

[0036] Figure 13 The figure is a schematic diagram showing the principle of calibration of the force sensor of the engine thrust measurement bench in the supersonic engine test bench of the present invention.

[0037] Figure 14 It is a partial structural diagram of the temperature simulation unit of the air intake system in the supersonic engine test bench of the present invention.

[0038] Figure 15 The figure is a schematic structural diagram of the exhaust system and the muffler device in the supersonic engine test bench of the present invention.

[0039] Figure 16 This is a structural schematic diagram of the internal structure of the muffler device of the supersonic engine test bench of the present invention, which can show the internal structure of the engine test bench of the present invention.

[0040] Figure 17 The figure is a schematic structural diagram of a three-layer silencer assembly in a specific embodiment of the silencer device in the supersonic engine test bench of the present invention.

[0041] Figure 18 It is a structural schematic diagram of a single-layer silencer assembly of a silencer device in a supersonic engine test bench of the present invention.

[0042] Figure 19The diagram is a structural diagram of a semi-thin silencer plate of a silencer device in a supersonic engine test bench according to the present invention.

[0043] Figure 20 It is a schematic structural diagram of the half-thickness silencer plate of the silencer device in the supersonic engine test bench of the present invention.

[0044] Figure 21 It is a schematic structural diagram of the thin and thick combined silencer plates of the silencer device in the supersonic engine test bench of the present invention.

[0045] Figure 22 It is a structural schematic diagram of a variable frequency diffuser in one angular direction of the silencer in the supersonic engine test bench of the present invention.

[0046] Figure 23 This is a structural schematic diagram of the variable frequency diffuser of the silencer device in the supersonic engine test bench of the present invention, viewed from another angle.

[0047] Figure 24 The present invention is a schematic structural diagram of a variable frequency diffuser guide cone in a variable frequency diffuser of a silencer device in a supersonic engine test bench. DETAILED DESCRIPTION

[0048] 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", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0049] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "abutted" 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.

[0050] The pressure, total pressure, static pressure, dynamic pressure, temperature, total temperature, static temperature, and dynamic temperature involved in the present invention are the same as those in the applicant's prior application (application number: CN201811164303.1, invention name: A supersonic engine test bench). In addition, the intake system of the engine test bench involved in the present invention is equipped with temperature sensors and pressure sensors at the inlet and outlet of the first medium channel, inside the first medium channel, at the inlet and outlet of the second medium channel, inside the second medium channel, at the inlet and outlet of the supersonic nozzle, and inside the supersonic nozzle. The temperature sensors and pressure sensors are both arranged in the direction of the airflow and are used to measure the total pressure and total temperature of the cross-section where the sensors are set.

[0051] A supersonic engine test bench, particularly suitable for supersonic engines with a Mach number of 1-5, such as turbofan engines, solid-fuel engines and other aerospace engines, is particularly suitable for a test bench for high-altitude multi-state point simulation tests of supersonic engines. Among the high-altitude multi-state points of the supersonic engine, the parameters of each state point include engine intake total pressure, intake air flow, intake oxygen composition, intake total temperature, engine fuel supply, and air ambient pressure. The supersonic engine test bench includes an air intake system, an engine thrust measurement bench, an exhaust system 700, a silencer 800 and a high-altitude simulation cabin 900; the high-altitude simulation cabin 900 is a sealed shell structure, and its appearance is not limited, and it can be a rectangular parallelepiped, an ellipsoid, etc.; the engine thrust measurement bench is fixedly installed in the high-altitude simulation cabin 900, and the test engine 1 is installed on the engine thrust measurement bench; the air intake system is connected to the test engine 1 and / or the exhaust system 700, one end of the exhaust system 700 is fixedly installed inside the high-altitude simulation cabin 900 through the shell surface of the high-altitude simulation cabin 900, and the other end is fixedly connected to the silencer 800.

[0052] The air intake system includes a supply source, a temperature simulation unit 60 and a supersonic nozzle 401 .

[0053] The supply sources include a fuel supply source 10 , an oxygen supply source 20 , an engine intake air supply source 30 , an alcohol supply source 40 and an ejector active airflow supply source 50 .

[0054] The temperature simulation unit 60 includes a tube 61 and a shell 62. The tube 61 is located within the shell 62. A first medium channel is formed within the tube 61, and a second medium channel is formed in the space between the outer wall of the tube 61 and the inner wall of the shell 62. When the temperature simulation unit 60 is in operation, a first medium flows through the first medium channel, and a second medium flows through the second medium channel. The first medium has a higher temperature than the second medium, and the first and second media exchange heat through the tube wall of the tube 61. The outlet of the supersonic nozzle 401 is fixedly connected to the intake port of the test engine 1. For the specific structure and connection method of the temperature simulation unit 60 and the supersonic nozzle 401, please refer to the applicant's prior application (Application No.: CN201811164305.0, Invention Title: A Supersonic Engine Test Bench Intake System or Application No.: CN201811164303.1, Invention Title: A Supersonic Engine Test Bench).

[0055] The fuel supply source 10 is connected to the test engine 1 through a pipeline, the oxygen supply source 20 and the engine intake supply source 30 are respectively connected to the inlet of the second medium channel through a pipeline, the outlet of the second medium channel is connected to the inlet of the straight section 610 of the supersonic nozzle 401 through a pipeline, and the outlet of the supersonic expansion section 650 of the supersonic nozzle 401 is connected to the intake of the test engine through a pipeline. The intake of the test engine 1 is connected to provide the test engine 1 with simulated engine supersonic intake flow, intake Mach number, intake total pressure and oxygen content; the alcohol supply source 40 is connected to the inlet of the first medium channel through a pipeline after passing through the igniter, and the outlet of the first medium channel is connected to the outside world. The igniter ignites the alcohol and burns it to generate heat, which is exchanged with the second medium in the second medium channel in the temperature simulation unit 60 to adjust the temperature of the second medium in the second medium channel, thereby realizing engine intake temperature simulation. The engine intake simulation of the present invention is realistic, highly accurate, and simple in structure.

[0056] Preferably, the exhaust system 700 of the present application is a tail chamber combined with an ejector structure, comprising a tail chamber section 710, an ejector low-pressure chamber 720, an ejector convergent section 730, an ejector straight section 740, and an ejector expansion section 750, which are fixedly connected in sequence. The ejector expansion section 750 is fixedly connected to the variable frequency diffuser 820 of the muffler 800. A replaceable small tail chamber is fixedly installed within the tail chamber section 710. The exhaust system 700 is prior art, as specifically described in the applicant's granted Chinese invention patent ZL 201610786167.4. The ejector active airflow supply source 50 is connected to the ejector low-pressure chamber 720 of the exhaust system 700 via a pipeline.

[0057] An engine fuel supply flow regulating valve 51 is provided on the pipeline connecting the fuel supply source 10 and the test engine 1, an oxygen supply flow regulating valve 53 is provided on the pipeline connecting the oxygen supply source 20 and the inlet of the second medium channel, an engine intake supply pressure regulating valve 55 is provided on the pipeline connecting the engine intake supply source 30 and the inlet of the second medium channel, an alcohol supply flow regulating valve 56 is provided on the pipeline connecting the alcohol supply source 40 and the inlet of the first medium channel, and an ejector active airflow supply pressure regulating valve 58 is provided on the pipeline connecting the ejector active airflow supply source 50 and the exhaust system 700, so as to realize parameter adjustment of each supply source and meet the simulation of multiple state points.

[0058] Preferably, the intake system includes an engine fuel supply shutoff valve 52, an oxygen supply shutoff valve 54, and an alcohol supply shutoff valve 57. The engine fuel supply shutoff valve 52 is disposed on a pipeline connecting the fuel supply source 10 and the test engine 1; the oxygen supply shutoff valve 54 is disposed on a pipeline connecting the oxygen supply source 20 and the inlet of the second medium channel; and the alcohol supply shutoff valve 57 is disposed on a pipeline connecting the alcohol supply source 40 and the inlet of the first medium channel. During use of the intake system, the engine fuel supply shutoff valve 52 is opened before opening the engine fuel supply flow regulating valve 51, the oxygen supply shutoff valve 54 is opened before opening the oxygen supply flow regulating valve 53, and the alcohol supply shutoff valve 57 is opened before opening the alcohol supply flow regulating valve 56. After closing the engine fuel supply flow regulating valve 51, the engine fuel supply shutoff valve 52 is closed; after closing the oxygen supply flow regulating valve 53, the oxygen supply shutoff valve 54 is closed; and after closing the alcohol supply flow regulating valve 56, the alcohol supply shutoff valve 57 is closed to ensure the safety of the intake system when not in a test state.

[0059] The engine thrust measurement test bench includes a fixed frame 100, a movable frame 200 and a loading measurement device; the loading measurement device includes a spring sheet, a loading mechanism 330 and a working force sensor 350; the movable frame 200 is suspended on the fixed frame 100 by the spring sheet, the loading mechanism 330 is fixedly mounted on the fixed frame 100, and the two ends of the working force sensor 350 are respectively connected to the fixed frame 100 and the movable frame 200.

[0060] The fixed frame includes a base 110, a front mounting seat 120, a loading mechanism mounting seat 130, a first fixed frame spring piece mounting seat 140, a fixed frame working force sensor mounting seat 150, a rear mounting seat 160 and a second fixed frame spring piece mounting seat 170; the base 110 is a rectangular parallelepiped structure, along the length direction of the base 110, the front mounting seat 120 and the rear mounting seat 160 are fixedly mounted on the front and rear ends of the base 110 respectively, and the rear mounting seat 160 includes a horizontal plate and a vertical plate, and the horizontal plate and the vertical plate form an "L" shape; the loading mechanism mounting seat 130 is fixedly mounted on the front mounting seat 120, the first fixed frame spring piece mounting seat 140 includes a first right fixed frame spring piece mounting seat 141 and a first left fixed frame spring piece mounting seat 142, the first right fixed frame spring piece mounting seat 141 and the first left fixed frame spring piece mounting seat 142 are fixedly mounted on the front end of the base 110 and are respectively located on both sides of the front mounting seat 120; the fixed frame working force sensor mounting seat 150 Fixedly mounted on the base 110 and located on the center line along the length direction of the base 110; the second fixed frame spring piece mounting seat 170 includes a second right fixed frame spring piece mounting seat 171 and a second left fixed frame spring piece mounting seat 172, and the second right fixed frame spring piece mounting seat 171 and the second left fixed frame spring piece mounting seat 172 are fixedly mounted on the rear end of the base 110 and are respectively located on both sides of the rear mounting seat 160.

[0061] The movable frame 200 includes a movable frame body 210, a first movable frame spring sheet mounting seat 220, a movable frame working force sensor mounting seat 230, a second movable frame spring sheet mounting seat 240 and a movable frame standard force sensor mounting seat 250. The movable frame body 210 includes a right movable frame body 211, a left movable frame body 212 and a movable frame connecting plate 260. The right movable frame body 211 and the left movable frame body 212 have the same structure, are both rectangular structures and are parallel to the base 110. The center lines of the right movable frame body 211 and the left movable frame body 212 along the length direction are parallel to the center line of the base 110 along the length direction. The movable frame connecting plates 260 are symmetrically arranged relative to the center line of the base 110 along the length direction, and the plurality of movable frame connecting plates 260 fix the right movable frame body 211 and the left movable frame body 212 to each other; along the length direction of the movable frame body 210, the movable frame standard force sensor mounting seat 250 is fixedly mounted on the front bottom surface of the movable frame body 210; the first movable frame spring leaf mounting seat 220 includes a first right movable frame spring leaf mounting seat and a first left movable frame spring leaf mounting seat, and the first right movable frame spring leaf mounting seat and the first left movable frame spring leaf mounting seat are respectively fixedly mounted on the right movable frame body 2 11 and the front end bottom surface of the left movable frame body 212 and are respectively located on both sides of the movable frame standard force sensor mounting seat 250; the movable frame working force sensor mounting seat 230 is fixedly installed on the bottom of a movable frame connecting plate 260 of the movable frame body 210 and is located on the center line along the length direction of the movable frame body 210; the second movable frame spring leaf mounting seat 240 includes a second right movable frame spring leaf mounting seat and a second left movable frame spring leaf mounting seat, and the second right movable frame spring leaf mounting seat and the second left movable frame spring leaf mounting seat are respectively fixedly mounted on the rear end bottom surfaces of the right movable frame body 211 and the left movable frame body 212.

[0062] The loading and measuring device includes a first spring piece 310, a second spring piece 320, a loading mechanism 330, a standard force sensor 340 and a working force sensor 350; the first spring piece 310 includes a first right spring piece 311 and a first left spring piece 312, the two ends of the first right spring piece 311 are respectively fixedly connected to the first right fixed frame spring piece mounting seat 141 and the first right movable frame spring piece mounting seat, the first left spring piece 312 The two ends are respectively fixedly connected to the first left fixed frame spring piece mounting seat 142 and the first left movable frame spring piece mounting seat; the second spring piece 320 includes a second right spring piece 321 and a second left spring piece 322, the two ends of the second right spring piece 321 are respectively fixedly connected to the second right fixed frame spring piece mounting seat 171 and the second right movable frame spring piece mounting seat, and the two ends of the second left spring piece 322 are respectively fixedly connected to the second left fixed frame spring piece mounting seat 172 and the second left movable frame spring piece mounting seat; the loading mechanism 330 is fixedly mounted on the horizontal plate of the front mounting seat 120, and the standard force sensor 340 is fixedly mounted on the movable frame body 210 On the front baffle, the loading mechanism 330 and the standard force sensor 340 are coaxially arranged and parallel to the center line of the base 110 along the length direction; the two ends of the working force sensor 350 are respectively fixedly connected to the fixed frame working force sensor mounting seat 150 and the movable frame working force sensor mounting seat 230, and the working force sensor 350 is coaxially arranged with the loading mechanism 330 and the standard force sensor 340; the loading mechanism 330 includes a servo motor, a motor power supply, a hydraulic loading device, and a calibration cylinder. The motor power supply is electrically connected to the servo motor, and the servo motor is connected to the hydraulic loading device and the calibration cylinder in turn, and the piston of the calibration cylinder is connected to the standard force sensor.

[0063] The engine thrust measurement test bench includes a measuring section bracket for supporting the measuring section, and the measuring section bracket includes a first measuring section bracket 410 and a second measuring section bracket 420 arranged coaxially, the first measuring section bracket 410 and the second measuring section bracket 420 have the same structure, and are both fixedly mounted on the top surface of the dynamic frame body 210; the measuring section bracket includes a measuring section bracket bracket 411, a measuring section bracket lower ring 412, a measuring section bracket upper ring 413, a measuring section bracket positioning mechanism 414 and a locking device 415; the bottom surface of the measuring section bracket bracket 411 is fixedly connected to the top surface of the dynamic frame body 210, the measuring section bracket lower ring 412 and the measuring section bracket upper ring 413 are both semicircular structures, and the measuring section bracket lower ring 412 and the measuring section bracket upper ring 413 are connected to form a circle; the measuring section bracket lower ring 412 and the measuring section bracket upper ring 413 are connected to form a circle; The bracket 411 is integrally formed; there are three measuring section bracket positioning mechanisms 414 with the same structure, which are used to position the measuring section for measuring the intake parameters of the test engine 1. In this application, the supersonic nozzle 401 is the measuring section, and a temperature sensor and a pressure sensor are fixedly installed on the pipe wall of the nozzle outlet. The temperature sensor and the pressure sensor are both arranged in the direction of the airflow, and are used to measure the total pressure and total temperature of the sensor cross section, that is, to measure the engine inlet gas parameters; the three measuring section bracket positioning mechanisms 414 are evenly distributed in the radial direction of the circle formed after being connected along the measuring section bracket lower ring 412 and the measuring section bracket upper ring 413, wherein one measuring section bracket positioning mechanism 414 is arranged on the top of the measuring section bracket upper ring 413, and the remaining two measuring section bracket positioning mechanisms 414 are arranged on the measuring section bracket lower ring 412; the measuring section bracket positioning mechanism 414 It includes a positioning mechanism nut 4141, a positioning mechanism locking nut 4142 and a positioning mechanism screw 4143. The positioning mechanism screw 4143 passes through the measuring section bracket lower ring 412 or the measuring section bracket upper ring 413. The positioning mechanism locking nut 4142 is sleeved on the positioning mechanism screw 4143 and placed on the outside of the measuring section bracket lower ring 412 or the measuring section bracket upper ring 413 to abut against the measuring section bracket lower ring 412 or the measuring section bracket upper ring 413, and is used to lock the positioning mechanism screw 4143. The positioning mechanism nut 4141 is sleeved on the positioning mechanism screw 4143 and abuts against the positioning mechanism locking nut 4142.There are two locking devices 415 with the same structure, which are used to fix the lower ring 412 of the measuring section bracket and the upper ring 413 of the measuring section bracket. The two locking devices 415 are set at the connecting ends of the lower ring 412 of the measuring section bracket and the upper ring 413 of the measuring section bracket. The locking devices 415 include an upper locking plate 4151, a lower locking plate 4152, a locking bolt 4153 and a locking nut 4154. The upper locking plate 4151 is fixedly connected to the measuring section bracket. The front end face of the measuring section bracket upper ring 413, the lower surface of the upper locking plate 4151 coincides with the lower surface of the measuring section bracket upper ring 413, the lower locking plate 4152 is fixedly connected to the front end face of the measuring section bracket lower ring 412, the upper surface of the lower locking plate 4152 coincides with the upper surface of the measuring section bracket lower ring 412, the locking bolt 4153 passes through the lower locking plate 4152 and the upper locking plate 4151 in sequence, and the locking nut 4154 cooperates with the locking bolt 4153 and abuts against the upper locking plate 4151.

[0064] The engine thrust measurement test bench includes a locking device, which includes a tightening screw 510, a tightening baffle 520 and a tightening nut 530. The tightening screw 510 passes through the rear end baffle of the dynamic frame body 210, the tightening baffle 520, the vertical plate of the rear mounting seat 160 and the tightening nut 530 in sequence. The tightening nut 530 cooperates with the tightening screw 510, and the tightening baffle 520 and the tightening nut 530 both abut against the vertical plate of the rear mounting seat 160.

[0065] The engine thrust measurement rig includes an engine mounting frame 600, which includes an engine mounting top frame 610, a left column 620 and a right column 630 of the same structure, a front joint 640, a rear joint 650 and a lifting lug 660; the bottom surfaces of the left column 620 and the right column 630 are aligned with the bottom surface of the movable frame 200. Detachable connection; the engine mounting bracket 610 is fixedly connected to the top surfaces of the left column 620 and the right column 630 to form a gantry type, the front joint 640 and the rear joint 650 are detachably mounted on the engine mounting bracket 610, and the lifting lug 660 is fixedly connected to the engine mounting bracket 610; the engine mounting bracket 610 includes a front beam 611, a rear beam 612 and a longitudinal beam 613, the front beam 611 and the rear beam 612 are arranged in parallel and are both fixedly connected to the longitudinal beam 613, the rear beam 612 is fixedly connected to one end of the longitudinal beam 613, the front beam 611, the rear beam 612 and the longitudinal beam 613 form a "earth" shape; the longitudinal beam 613 is provided with a mounting hole 614 for mounting the front joint 640 and the rear joint 650; the left column 620 It includes a front column 621 , a rear column 622 and column connecting rods 623 . The front column 621 and the rear column 622 are arranged in parallel and fixedly connected by a plurality of column connecting rods 623 .

[0066] The engine thrust measurement bench includes a force sensor calibration device, which includes an industrial computer, a display, a standard force sensor data acquisition device and a working force sensor data acquisition device; the industrial computer is electrically connected to the display and the servo motor respectively, the standard force sensor data acquisition device is electrically connected to the standard force sensor and the industrial computer respectively, and the working force sensor data acquisition device is electrically connected to the working force sensor and the industrial computer respectively.

[0067] The silencer 800 includes a tower body 810, a variable frequency diffuser 820 and a silencer plate assembly 830; a top cover 811 is provided on the top of the tower body 810, and a variable frequency diffuser mounting hole 812 for mounting the variable frequency diffuser 820 is opened on one side of the tower body 810; the variable frequency diffuser 820 passes through the variable frequency diffuser mounting hole 812 and is horizontally fixedly installed in the tower body 810; the silencer plate assembly 830 is fixedly installed in the tower body 810. Preferably, the tower body is a reinforced concrete structure.

[0068] The variable frequency diffuser 820 includes a variable frequency diffuser cylinder 821 and a variable frequency diffuser guide cone 823. The variable frequency diffuser cylinder 821 is a hollow circular cylinder. The surface of the cylinder is provided with a plurality of variable frequency diffuser outlet holes 822 for exhausting gas. The plurality of variable frequency diffuser outlet holes 822 are all through holes that penetrate the circular cylinder. The variable frequency diffuser guide cone 823 is a cone. The conical surface of the variable frequency diffuser guide cone 823 is provided inside the circular cylinder. The outer diameter of the bottom of the variable frequency diffuser guide cone 823 is the same as the inner diameter of the circular cylinder. The outer circle of the bottom of the cone 823 is fixedly connected to one end face of the circular cylinder, closing one end of the variable frequency diffuser cylinder 821. The gas discharged from the engine test bench enters from the end face of the open end of the variable frequency diffuser cylinder 821, is guided by the variable frequency diffuser guide cone 823, and is discharged from a number of variable frequency diffuser outlet holes 822. By setting the conical variable frequency diffuser guide cone 823, the gas entering the variable frequency diffuser cylinder 821 is guided, so that the gas entering the variable frequency diffuser cylinder 821 is evenly discharged from a number of variable frequency diffuser outlet holes 822, which is convenient for subsequent silencing and improves the silencing effect.

[0069] The silencer assembly 830 includes a lower silencer assembly 8301, a middle silencer assembly 8302 and an upper silencer assembly 8303 arranged in sequence from bottom to top; each layer of silencer assembly includes a semi-thin silencer 831, a semi-thick silencer 832 and a thin-thick combination silencer 833 arranged at intervals. In each layer of silencer assembly, the semi-thin silencer 831 and the semi-thick silencer 832 are arranged at both ends and fixedly connected to the front and rear end surfaces of the tower body 810. A number of thin-thick combination silencers 833 are arranged between the semi-thin silencer 831 and the semi-thick silencer 832, and the adjacent silencers form an airflow channel; the installation method of each layer of silencer assembly and the connection method with the tower body are existing technologies, and the specific method is basically consistent with the applicant's prior application (CN201420057351.1).

[0070] On the same end side, the types of silencers of two adjacent layers are different, so that the air flow channels formed by adjacent silencer assembly are staggered, thereby improving the silencer ability of the silencer device. In a preferred embodiment of the present application, along the silencer tower from front to back, in the lower silencer assembly 8301, the silencers are arranged in the form of semi-thin silencer 831, thin-thick combination silencer 833, thin-thick combination silencer 833, and semi-thick silencer 832, wherein the thick silencer parts of the thin-thick combination silencer 833 are all facing the semi-thin silencer 831; the middle silencer assembly In 8302, the arrangement of the sound-absorbing sheets is a half-thick sound-absorbing sheet 832, a thin-thick combination sound-absorbing sheet 833, a thin-thick combination sound-absorbing sheet 833, and a half-thin sound-absorbing sheet 831, wherein the thick sound-absorbing sheet portions in the thin-thick combination sound-absorbing sheet 833 are all facing the half-thin sound-absorbing sheet 831; in the upper sound-absorbing sheet assembly 8303, the arrangement of the sound-absorbing sheets is a half-thin sound-absorbing sheet 831, a thin-thick combination sound-absorbing sheet 833, a thin-thick combination sound-absorbing sheet 833, and a half-thick sound-absorbing sheet 832, wherein the thick sound-absorbing sheet portions in the thin-thick combination sound-absorbing sheet 833 are all facing the half-thin sound-absorbing sheet 831.

[0071] The semi-thin sound-absorbing sheet 831 comprises a semi-thin sound-absorbing sheet flat sheet 8311 and two semi-thin sound-absorbing sheet guide cones 8312, the two semi-thin sound-absorbing sheet guide cones 8312 are fixedly connected to both ends of the semi-thin sound-absorbing sheet flat sheet 8311, preferably, the two semi-thin sound-absorbing sheet guide cones 8312 are integrally formed with the semi-thin sound-absorbing sheet flat sheet 8311; the surfaces of the semi-thin sound-absorbing sheet flat sheet 8311 and the semi-thin sound-absorbing sheet guide cone 8312 are both provided with a plurality of sound-absorbing sheet micropores 834, the plurality of sound-absorbing sheet micropores 834 are all through holes penetrating the surfaces of the semi-thin sound-absorbing sheet flat sheet 8311 and the semi-thin sound-absorbing sheet guide cone 8312, wherein the semi-thin sound-absorbing sheet 831 The structure is a prior art, which is a half-sheet structure of the sheet assembly in the applicant's prior application (application number: CN201420056663.0, invention name: Sheet assembly for silencer). By setting a semi-thin silencer guide cone 8312, the gas entering the air flow channel is guided, making the gas flow uniform and further improving the silencer effect.

[0072] The semi-thick silencer 832 comprises a semi-thick silencer flat sheet 8321 and two semi-thick silencer guide cones 8322, the two semi-thick silencer guide cones 8322 being fixedly connected to both ends of the semi-thick silencer flat sheet 8321. Preferably, the two semi-thick silencer guide cones 8322 are integrally formed with the semi-thick silencer flat sheet 8321; a plurality of silencer micropores 834 are provided on the surfaces of the semi-thick silencer flat sheet 8321 and the semi-thick silencer guide cone 8322, and the plurality of silencer micropores 834 are through holes penetrating the surfaces of the semi-thick silencer flat sheet 8321 and the semi-thick silencer guide cone 8322; wherein, the semi-thick silencer 832 The structure is a prior art, which is a half-sheet structure of the thin sheet assembly in the applicant's prior application (application number: CN201420056662.6, invention name: thick sheet assembly for silencer); by providing a half-thick silencer guide cone 8322, the gas entering the air flow channel is guided, making the gas flow uniform, and further improving the silencer effect.

[0073] The thin-thick combination silencer 833 is a combination piece formed by the semi-thin silencer 831 and the semi-thick silencer 832 being fixedly connected in the horizontal plane. In the combined thin-thick combination silencer 833, the semi-thin silencer flat piece 8311 and the semi-thick silencer flat piece 8321 are arranged in parallel to constitute the thin-thick combination silencer flat piece 8331 of the thin-thick combination silencer 833, and the two semi-thin silencer guide cones 8312 and the two semi-thick silencer guide cones 8322 constitute the two thin-thick combination silencer guide cones 8332 of the thin-thick combination silencer 833; by arranging the thin-thick combination silencer guide cone 8332, the gas entering the air flow channel can be diverted, so that the gas flows evenly, thereby further improving the silencer effect.

[0074] The thickness of the semi-thin sound-absorbing sheet 831 is L1, the thickness of the semi-thick sound-absorbing sheet 832 is L2, and the thickness of the thin-thick combined sound-absorbing sheet 833 is L3, wherein L1<L2<L3, and L3=L1+L2.

[0075] Preferably, the diameter of the micropores 834 of the sound-absorbing plate is 0.6 mm to 1 mm, and further preferably, the diameter of the micropores 834 of the sound-absorbing plate is 0.8 mm.

[0076] Preferably, the diameter of the frequency diffuser outlet hole 822 is 40 mm to 80 mm, and further preferably, the diameter of the frequency diffuser outlet hole 822 is 60 mm.

[0077] Preferably, the horizontal cross-section inside the tower body 810 is a square channel, and the wall thickness of the tower body 810 is 0.5 m. Further preferably, the horizontal cross-section inside the tower body 810 is a square channel.

[0078] Preferably, the thickness L1 of the semi-thin sound-absorbing sheet 831 is 80 mm-85 mm, and further preferably, the thickness L1 of the semi-thin sound-absorbing sheet 831 is 82 mm.

[0079] Preferably, the thickness L2 of the half-thickness sound-absorbing sheet 832 is 195 mm-205 mm, and further preferably, the thickness L2 of the half-thickness sound-absorbing sheet 832 is 200 mm.

[0080] When using the supersonic engine test bench to test the engine under test, the following steps are included:

[0081] S100), install the test engine 1 and the measurement section

[0082] S110), passing the measuring section for measuring engine intake parameters through the first measuring section bracket 410 and the second measuring section bracket 420 in sequence, and placing the measuring section in the first measuring section bracket 410 and the second measuring section bracket 420;

[0083] S120), installing the front joint 640 and the rear joint 650 on the longitudinal beam 613 according to the suspension position of the test engine 1;

[0084] S130), after the engine mounting frame 600 is mounted on the dynamic frame body 210, the test engine 1 is mounted on the front joint 640 and the rear joint 650;

[0085] S140) Adjust the measuring section, connect one end of the measuring section to the air intake of the test engine 1, adjust the positioning mechanism screw 4143 in the measuring section bracket positioning mechanism 414, make the measuring section coaxial with the engine air intake, and then rotate the positioning mechanism locking nut 4142 and the positioning mechanism nut 4141 in the measuring section bracket positioning mechanism 414 in sequence.

[0086] S200) Disassemble the locking device

[0087] Loosen the fixing nut 530 , pull out the fixing screw 510 from the vertical plate of the rear mounting seat 160 , the fixing baffle 520 , and the baffle at the rear end of the movable frame body 210 in sequence, and then take out the fixing baffle 520 .

[0088] S300), determining the working force sensor error

[0089] S310), the industrial computer controls the servo motor to start and drive the hydraulic loading device to work, the hydraulic loading device drives the calibration cylinder to work, the piston of the calibration cylinder drives the standard force sensor 340 to move, and then drives the movable frame body 210 to move, and during the displacement of the movable frame body 210, force is applied to the working force sensor 350;

[0090] S320), the hydraulic loading device drives the calibration cylinder to continue applying the loading force to the standard force sensor 340 to a predetermined value and then unloading the loading force to zero; the standard force sensor data acquisition device and the working force sensor data acquisition device respectively collect the force values ​​output by the standard force sensor 340 and the working force sensor 350 during the process of applying the loading force and unloading the loading force and feed them back to the industrial computer, and the display shows the force values ​​output by the standard force sensor 340 and the working force sensor 350 during the process of applying the loading force and unloading the loading force collected by the standard force sensor data acquisition device and the working force sensor data acquisition device;

[0091] S330), draw a characteristic curve diagram of the standard force sensor 340 and the working force sensor 350 according to the force values ​​output by the standard force sensor 340 and the working force sensor 350 during the process of applying the loading force and unloading the loading force, which are collected by the standard force sensor data acquisition device and the working force sensor data acquisition device and displayed on the display; under the same loading force, the difference between the force value output by the working force sensor 350 collected by the working force sensor data acquisition device and the force value output by the standard force sensor 340 collected by the standard force sensor data acquisition device is the working force sensor error.

[0092] S400), simulate the engine high-altitude flight environment pressure and muffle the exhaust gas from the exhaust system

[0093] S410) Start the ejector in the exhaust system 700 to extract the gas in the high-altitude simulation cabin 900 so that the pressure in the high-altitude simulation cabin 900 is the same as the ambient pressure at the altitude at which the engine is flying at high altitude.

[0094] S420), the gas discharged from the exhaust system 700 enters from the end face of the open end of the variable frequency diffuser cylinder 821, is guided by the variable frequency diffuser guide cone 823, and is discharged from the multiple variable frequency diffuser outlet holes 822. The air flow passes through the dry variable frequency diffuser outlet holes 822 to shift the noise frequency to high frequency, and the difficulty of noise control is reduced by using the principle that high frequency is easier to control than low frequency. The gas discharged from the multiple variable frequency diffuser outlet holes 822 is silenced and reduced in noise through the staggered air flow channels composed of three layers of silencer plate components, and then discharged from the outlet at the top of the tower body 810.

[0095] S500), simulate supersonic engine intake parameters (for specific simulation methods, please refer to the applicant's prior application: Application No.: CN201811164305.0, Invention Name: A Supersonic Engine Test Bench Intake System or Application No.: CN201811164305.0, Invention Name: A Supersonic Engine Test Bench Intake System or Application No.: CN201811164303.1, Invention Name: A Supersonic Engine Test Bench).

[0096] S510) adjusting the engine intake air supply pressure regulating valve and the oxygen supply flow regulating valve according to the intake air total pressure and oxygen content at the first simulation state point, so that the total pressure and oxygen content of the second medium passing through the supersonic expansion section outlet of the supersonic nozzle are the same as the intake air total pressure and oxygen content of the engine at the first simulation state point.

[0097] S520), according to the total temperature of the intake air at the first simulation state point, the alcohol supply flow regulating valve is adjusted and the igniter is started to ignite the alcohol to make it burn. The burning alcohol exchanges heat with the second medium in the first medium channel and the second medium in the second medium channel, so that the total temperature of the second medium passing through the outlet of the supersonic expansion section of the supersonic nozzle is the same as the total temperature of the intake air of the engine at the first simulation state point.

[0098] S530) adjusting the engine intake supply pressure regulating valve according to the total intake pressure at the first simulation state point so that the total pressure of the second medium passing through the outlet of the supersonic expansion section of the supersonic nozzle is the same as the total intake pressure of the engine at the first simulation state point.

[0099] S600), simulate the first state point and measure the thrust of the test engine at this state point

[0100] The engine fuel supply flow regulating valve is adjusted according to the fuel demand at the first simulation state point of the engine so that the fuel supplied by the fuel supply source is the same as the fuel demand at the first simulation state point of the engine. The engine is ignited and an intake simulation test at the first simulation state point is performed. The display shows the force value output by the working force sensor 350 collected by the working force sensor data acquisition device.

[0101] S700), simulate the Nth state point and measure the thrust of the test engine at this state point

[0102] The oxygen supply flow regulating valve, the engine intake supply pressure regulating valve, the alcohol supply flow regulating valve and the engine fuel supply flow regulating valve are respectively adjusted so that the total pressure, total temperature and oxygen content of the second medium at the outlet of the supersonic expansion section of the supersonic nozzle are the same as the intake total pressure, total temperature and oxygen content of the engine at the Nth simulation state point, and the fuel supplied by the fuel supply source is the same as the fuel demand of the engine at the Nth simulation state point; wherein N≥2; the intake simulation test of the engine at the Nth state point is started and the intake simulation test is performed at the state point, and the thrust measurement of the test engine at the state point is measured according to the method of step S500.

[0103] S800), close the test bench intake system and exhaust system

[0104] After the engine is turned off, close the engine fuel supply flow regulating valve, oxygen supply flow regulating valve, engine intake supply pressure regulating valve and alcohol supply flow regulating valve, and then close the ejector active airflow supply pressure regulating valve.

[0105] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0106] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A method for testing a test engine using a supersonic engine test bench, characterized in that ， A supersonic engine test bench, characterized by comprising an air intake system, an engine thrust measurement bench, an exhaust system, a silencer, and a high-altitude simulation cabin; the high-altitude simulation cabin is a sealed shell structure, the engine thrust measurement bench is fixedly installed in the high-altitude simulation cabin, and the test engine is installed on the engine thrust measurement bench; the air intake system is connected to the test engine or the exhaust system, one end of the exhaust system passes through the shell surface of the high-altitude simulation cabin and is fixedly installed inside the high-altitude simulation cabin, and the other end is fixedly connected to the silencer; The silencer device includes a tower body, a variable frequency diffuser and a silencer assembly; a top cover is provided on the top of the tower body, and a variable frequency diffuser mounting hole is provided on one side of the tower body; the variable frequency diffuser is passed through the variable frequency diffuser mounting hole and is fixedly installed horizontally in the tower body; the silencer assembly is fixedly installed in the tower body; The variable frequency diffuser includes a variable frequency diffuser cylinder and a variable frequency diffuser guide cone. The variable frequency diffuser cylinder is a hollow circular cylinder with a plurality of variable frequency diffuser air outlet holes provided on the surface of the cylinder. The plurality of variable frequency diffuser air outlet holes are through holes penetrating the circular cylinder. The variable frequency diffuser guide cone is a conical shape, with a conical surface of the variable frequency diffuser guide cone provided inside the circular cylinder, and the outer circle of the bottom of the variable frequency diffuser guide cone is fixedly connected to one end surface of the circular cylinder. The sound-absorbing plate assembly includes a lower sound-absorbing plate assembly, a middle sound-absorbing plate assembly and an upper sound-absorbing plate assembly which are arranged in sequence from bottom to top; Each layer of the sound-absorbing component includes a semi-thin sound-absorbing sheet, a semi-thick sound-absorbing sheet and a thin-thick combination sound-absorbing sheet. The thin-thick combination sound-absorbing sheet is a combination sheet formed by fixing the semi-thin sound-absorbing sheet and the semi-thick sound-absorbing sheet in a horizontal plane. In the combined thin-thick combination sound-absorbing sheet, the semi-thin sound-absorbing sheet flat sheet and the semi-thick sound-absorbing sheet flat sheet are arranged in parallel to form a thin-thick combination sound-absorbing sheet flat sheet of the thin-thick combination sound-absorbing sheet. Two semi-thin sound-absorbing sheet guide cones and two half-thick sound-absorbing sheet guide cones form two thin-thick combination sound-absorbing sheet guide cones of the thin-thick combination sound-absorbing sheet. Along the direction from front to back of the silencer tower, in the lower-layer silencer plate assembly, the silencer plates are arranged in the following manner: semi-thin silencer plates, thin-thick combination silencer plates, thin-thick combination silencer plates, and semi-thick silencer plates, wherein the thick silencer plate portions of the thin-thick combination silencer plates all face the semi-thin silencer plates; in the middle-layer silencer plate assembly, the silencer plates are arranged in the following manner: semi-thick silencer plates, thin-thick combination silencer plates, thin-thick combination silencer plates, and semi-thin silencer plates, wherein the thick silencer plate portions of the thin-thick combination silencer plates all face the semi-thin silencer plates; in the upper-layer silencer plate assembly, the silencer plates are arranged in the following manner: semi-thin silencer plates, thin-thick combination silencer plates, thin-thick combination silencer plates, and semi-thick silencer plates, wherein the thick silencer plate portions of the thin-thick combination silencer plates all face the semi-thin silencer plates; The method comprises the following steps: S100) Install the test engine and measurement section S110), passing the measuring section for measuring engine intake parameters through the first measuring section bracket and the second measuring section bracket in sequence, and placing the measuring section in the first measuring section bracket and the second measuring section bracket; S120), installing the front joint and the rear joint on the engine mounting top frame according to the suspension position of the test engine; S130), after installing the engine mounting frame onto the dynamic frame body, install the test engine onto the front joint and the rear joint; S140), adjusting the measuring section, connecting one end of the measuring section to the air inlet of the engine under test, adjusting the measuring section bracket to make the measuring section coaxial with the engine air inlet, and then positioning the measuring section; S200) Remove the locking device Loosen the locking nut, pull out the locking screw from the vertical plate of the rear mounting seat, the locking baffle, and the baffle at the rear end of the movable frame in sequence, and then remove the locking baffle; S300) Determine the error of the working force sensor S310), the industrial computer controls the servo motor to start and drive the hydraulic loading device to work, the hydraulic loading device drives the calibration cylinder to work, the piston of the calibration cylinder drives the standard force sensor to move, and then drives the dynamic frame to move, and during the displacement of the dynamic frame, force is applied to the working force sensor; S320), the hydraulic loading device drives the calibration cylinder to continue applying the loading force to the standard force sensor to a predetermined value and then unloading the loading force to zero; the standard force sensor data acquisition device and the working force sensor data acquisition device respectively collect the force values ​​output by the standard force sensor and the working force sensor during the process of applying the loading force and unloading the loading force and feed them back to the industrial computer, and the display displays the force values ​​output by the standard force sensor and the working force sensor during the process of applying the loading force and unloading the loading force collected by the standard force sensor data acquisition device and the working force sensor data acquisition device; S330), plotting characteristic curves of the standard force sensor and the working force sensor based on the force values ​​output by the standard force sensor and the working force sensor during the process of applying and unloading the loading force, as collected by the standard force sensor data collection device and the working force sensor data collection device and displayed on the display; under the same loading force, the difference between the force value output by the working force sensor collected by the working force sensor data collection device and the force value output by the standard force sensor collected by the standard force sensor data collection device is the working force sensor error; S400), simulate the engine's high-altitude flight environment pressure and muffle the exhaust gas from the exhaust system S410), starting the ejector in the exhaust system to extract the gas in the high-altitude simulation cabin so that the pressure in the high-altitude simulation cabin is the same as the ambient pressure at the altitude at which the engine is flying at high altitude; S420) The gas discharged from the exhaust system enters from the end face of one end of the variable frequency diffuser cylinder opening, is guided by the variable frequency diffuser guide cone, and is discharged from a number of variable frequency diffuser outlet holes. The gas discharged from the number of variable frequency diffuser outlet holes is silenced and reduced in noise by the staggered air flow channels formed by the three-layer silencer plate assembly, and is then discharged from the outlet at the top of the tower body; S500), simulate supersonic engine intake parameters S510), adjusting the engine intake air supply pressure regulating valve and the oxygen supply flow regulating valve according to the intake air total pressure and oxygen content at the simulation state point, so that the total pressure and oxygen content of the second medium passing through the supersonic expansion section outlet of the supersonic nozzle are the same as the intake air total pressure and oxygen content of the engine at the simulation state point; S520), adjusting the alcohol supply flow control valve according to the total intake air temperature at the simulation state point and starting the igniter to ignite the alcohol to cause the alcohol to burn, and the burning alcohol exchanges heat with the second medium in the second medium channel in the first medium channel, so that the total temperature of the second medium passing through the supersonic expansion section outlet of the supersonic nozzle is the same as the total intake air temperature of the engine at the simulation state point; S530), adjusting the engine intake supply pressure regulating valve according to the total intake pressure at the simulation state point, so that the total pressure of the second medium passing through the supersonic expansion section outlet of the supersonic nozzle is the same as the total intake pressure of the engine at the simulation state point; S600), state point simulation test and measurement of the thrust of the test engine at this state point The engine fuel supply flow regulating valve is adjusted according to the fuel demand of the engine at the simulated state point so that the fuel supplied by the fuel supply source is equal to the fuel demand of the engine at the simulated state point, the engine is ignited, and an intake simulation test at the simulated state point is performed, and a display shows the force value output by the working force sensor collected by the working force sensor data acquisition device; S700), simulation test at the Nth state point and measurement of the thrust of the test engine at this state point Respectively adjusting the oxygen supply flow control valve, the engine intake supply pressure control valve, the alcohol supply flow control valve, and the engine fuel supply flow control valve so that the total pressure, total temperature, and oxygen content of the second medium at the outlet of the supersonic expansion section of the supersonic nozzle are the same as the intake total pressure, total temperature, and oxygen content of the engine at the Nth simulation state point, and the fuel supplied by the fuel supply source is the same as the fuel demand of the engine at the Nth simulation state point; wherein N ≥ 2; starting the engine intake simulation test at the Nth state point, and measuring the thrust of the test engine at the state point according to the method of step S500; S800), close the test bench intake system and exhaust system After the engine is turned off, close the engine fuel supply flow regulating valve, oxygen supply flow regulating valve, engine intake supply pressure regulating valve and alcohol supply flow regulating valve, and then close the ejector active airflow supply pressure regulating valve.

2. The method according to claim 1, wherein: The air intake system includes a supply source, a temperature simulation unit and a supersonic nozzle; the supply source includes a fuel supply source, an oxygen supply source, an engine intake air supply source, an alcohol supply source and an ejector active airflow supply source.

3. The method according to claim 1, wherein: The engine thrust measurement bench includes a fixed frame, a dynamic frame and a loading measurement device; the loading measurement device includes a spring sheet, a loading mechanism and a working force sensor; the dynamic frame is suspended on the fixed frame through the spring sheet, the loading mechanism is fixedly installed on the fixed frame, and the two ends of the working force sensor are respectively connected to the fixed frame and the dynamic frame.

4. The method according to claim 3, wherein: The movable frame includes a movable frame body, a first movable frame spring sheet mounting seat, a movable frame working force sensor mounting seat, a second movable frame spring sheet mounting seat and a movable frame standard force sensor mounting seat; along the length direction of the movable frame body, the movable frame standard force sensor mounting seat is fixedly mounted on the front end bottom surface of the movable frame body; the first movable frame spring sheet mounting seat includes two fixedly mounted on the front end bottom surface of the movable frame body and respectively located on both sides of the movable frame standard force sensor mounting seat; the movable frame working force sensor mounting seat is fixedly mounted on the bottom of the movable frame body and located on the center line along the length direction of the movable frame body; the second movable frame spring sheet mounting seat includes two respectively fixedly mounted on the rear end bottom surface of the movable frame body.

5. The method according to claim 4, characterized in that: The fixed frame includes a base, a front mounting seat, a loading mechanism mounting seat, a first fixed frame spring piece mounting seat, a fixed frame working force sensor mounting seat, a rear mounting seat and a second fixed frame spring piece mounting seat; the base is a rectangular structure, and along the length direction of the base, the front mounting seat and the rear mounting seat are respectively fixedly mounted on the front end and the rear end of the base, and the rear mounting seat includes a horizontal plate and a vertical plate, and the horizontal plate and the vertical plate form an "L" shape; the loading mechanism mounting seat is fixedly mounted on the front mounting seat, and the first fixed frame spring piece mounting seat includes 2, which are fixedly mounted on the front end of the base and are respectively located on both sides of the front mounting seat; the fixed frame working force sensor mounting seat is fixedly mounted on the base and is located on the center line along the length direction of the base; the second fixed frame spring piece mounting seat includes 2, which are fixedly mounted on the rear end of the base and are respectively located on both sides of the rear mounting seat.

6. The method according to claim 5, characterized in that: The loading and measuring device includes a first spring sheet, a second spring sheet, a loading mechanism, a standard force sensor and a working force sensor; the first spring sheet includes two, each first spring sheet is fixedly connected to a first fixed frame spring sheet mounting seat and a first movable frame spring sheet mounting seat, and the second spring sheet includes two, each second spring sheet is fixedly connected at both ends to a second fixed frame spring sheet mounting seat and a second movable frame spring sheet mounting seat; the loading mechanism is fixedly mounted on the transverse plate of the front mounting seat, the standard force sensor is fixedly mounted on the baffle at the front end of the movable frame body, the loading mechanism and the standard force sensor are coaxially arranged and parallel to the center line of the base along the length direction; the two ends of the working force sensor are fixedly connected to the fixed frame working force sensor mounting seat and the movable frame working force sensor mounting seat, and the working force sensor is coaxially arranged with the loading mechanism and the standard force sensor.

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