Rocket engine short-time high-pressure high-speed jet flow simulation system and method

Abstract

The invention provides a rocket engine short-time high-pressure high-speed jet flow simulation system and method.The simulation system comprises a high-pressure air source, a high-pressure storage tank, a Laval nozzle, a quick release mechanism, a test cabin and a measurement and control system, and the quick release mechanism is arranged in the throat of the Laval nozzle; the quick release mechanism is used for sealing and releasing the high-pressure gas stored in the high-pressure storage tank, the quick release mechanism is controlled by the measurement and control system to execute the release action, the high-pressure gas generates high-pressure high-speed jet flow through the Laval nozzle and acts on a to-be-tested piece in the test cabin, and high-pressure high-speed jet flow simulation of the rocket engine is achieved. Compared with a traditional device and method, cold airflow (air and / or nitrogen) is used for simulation, and the safety is remarkably improved; jet flows under different working conditions can be simulated only by adjusting parameters of the high-pressure storage tank, and reproducibility is good; core physical characteristics of high pressure, high speed, high noise and the like of real rocket jet flow are effectively reproduced, and key support is provided for structural bearing and acoustic vibration environment adaptability assessment.

Description

Technical Field

[0001] This invention belongs to the field of rocket engine bottom surface testing and simulation technology, specifically involving a rocket engine short-time high-pressure high-speed jet simulation system and method. Background Technology

[0002] Rocket engines, especially solid rocket engines, generate high-temperature, high-pressure, and high-speed exhaust gases during operation. These gases create a complex and severe aerodynamic impact and vibration environment on the rocket's tail section and surrounding equipment, such as the tail section and interstage sections. Accurately reproducing these exhaust effects in ground tests is a crucial prerequisite for verifying the thermal protection performance, mechanical load-bearing capacity, and overall environmental adaptability of these components and structures.

[0003] Currently, there are three main experimental methods commonly used to simulate this jet environment, but all of them have significant shortcomings:

[0004] Firstly, full-scale engine hot-fire testing. While this method can most realistically reproduce actual jet flow conditions, it suffers from extremely high testing costs, significant safety risks, and long preparation cycles. Furthermore, it is difficult to frequently adjust operating parameters, thus failing to meet the needs of high-frequency, multi-condition testing and verification.

[0005] Secondly, there is the scaled-down engine hot test. Although its cost is lower than that of the full-scale test, it is difficult to simultaneously meet the multi-dimensional similarity criteria such as geometry, aerodynamics, thermodynamics and chemistry. In particular, the simulation results are prone to distortion due to the scale effect in key physical parameters such as jet shock wave structure and vibration impact, resulting in a significant deviation between the simulation results and the actual engine operating conditions.

[0006] Third, pure numerical simulation techniques (such as computational fluid dynamics, CFD). Although this method has the advantages of low cost, high speed and flexible settings, the reliability of its calculation results depends heavily on the accuracy of the boundary conditions and the precision of the physical model. It still needs to rely on physical experimental data for verification and correction, so it cannot be used as an independent basis for verification and design. Summary of the Invention

[0007] The purpose of this invention is to address the problem that existing rocket engine jet simulation methods cannot fully and accurately reproduce the physical characteristics of real engine jets under the premise of controllable cost, high safety, and good flexibility. Instead, it provides a short-time high-pressure high-speed jet simulation system and method for rocket engines. This method is based on a cold gas flow (no combustion reaction) approach, which reproduces the core physical characteristics of the jet by instantaneously releasing high-pressure gas. It also has the advantages of high safety, low cost, easy parameter adjustment, and strong repeatability, thus meeting the urgent need for efficient, accurate, and reliable verification of jet effects in aerospace equipment development.

[0008] To achieve the above objectives, the technical solution provided by this invention is:

[0009] A short-term high-pressure high-speed jet simulation system for rocket engines includes a high-pressure gas source, a high-pressure storage tank, a Laval nozzle, a rapid release mechanism, an experimental chamber, and a measurement and control system;

[0010] The high-pressure gas source is connected to the inlet of the high-pressure storage tank to provide high-pressure gas;

[0011] The outlet of the high-pressure storage tank is connected to the inlet of the Laval nozzle, and the outlet of the Laval nozzle is sealed to the opening of the test chamber and faces the test piece set inside the test chamber.

[0012] The quick-release mechanism is installed inside the Laval nozzle and close to the outlet of the high-pressure storage tank; the quick-release mechanism is used to seal and release the high-pressure gas stored in the high-pressure storage tank, and to generate a high-pressure, high-speed jet when the gas is released;

[0013] The measurement and control system is used to control the rapid release mechanism to perform the release action and monitor the test parameters.

[0014] Furthermore, the rapid release mechanism includes a high-pressure diaphragm, a triggering device, and a diaphragm fixing clamp;

[0015] A high-pressure diaphragm is placed inside the throat of the Laval nozzle, and its edges are clamped and fixed by a diaphragm fixing clamp to seal or release high-pressure gas.

[0016] The triggering device is located on the high-voltage diaphragm and is used to break the high-voltage diaphragm under the control of the measurement and control system to release high-pressure gas.

[0017] Furthermore, the triggering device is an electric detonator drive circuit or a shaped charge lock.

[0018] Furthermore, the Laval nozzle is a split type, consisting of a nozzle contraction section and a nozzle expansion section;

[0019] The diaphragm fixing fixture includes a first connecting flange, a second connecting flange, and two fixture units; the first connecting flange is coaxially fixed to the docking port of the nozzle contraction section, and the second connecting flange is coaxially fixed to the docking port of the nozzle expansion section.

[0020] The edge of the high-pressure diaphragm is clamped between the first connecting flange and the second connecting flange, and the first connecting flange and the second connecting flange are axially fixed by two individual clamps.

[0021] Furthermore, the clamp unit includes a first clamping body and a second clamping body that cooperate with each other, and the side walls of the first clamping body and the side walls of the second clamping body are provided with a first clamping portion and a second clamping portion that cooperate with each other.

[0022] The first connecting flange and the second connecting flange are clamped between the first clamping part and the second clamping part.

[0023] Furthermore, the measurement and control system includes a control unit, a measurement unit, a high-speed data acquisition instrument, and a human-machine interface;

[0024] The control unit is used to control the start and stop of the high-pressure gas source and to send trigger commands to the quick release mechanism;

[0025] The measurement unit includes various sensors installed on the high-pressure storage tank, Laval nozzle, and test piece, which are used in conjunction with a high-speed data acquisition instrument to collect and record data during the jet test in real time.

[0026] The human-computer interface is used to set test parameters, view real-time test process data, and store and replay test data.

[0027] Furthermore, an inflation valve is installed on the high-pressure pipeline between the high-pressure gas source and the high-pressure storage tank, and a pressure gauge and a safety valve are installed on the high-pressure storage tank to detect the pressure and ensure the safety of the storage pressure.

[0028] This invention also provides a method for simulating short-term high-pressure, high-speed jets in rocket engines, based on the aforementioned jet simulation device; the jet simulation method includes the following steps:

[0029] Step 1: Calculate and determine the initial pressure, volume, and filling type of the high-pressure storage tank based on the total pressure, total temperature, mass flow rate, and duration of the target rocket engine jet.

[0030] Step 2: Install the test piece into the test chamber; start the high-pressure gas source and fill the high-pressure storage tank with high-pressure gas; at this time, the high-pressure gas is sealed inside the high-pressure storage tank;

[0031] Step 3: Control the rapid release mechanism to release the high-pressure gas in the high-pressure storage tank;

[0032] The high-pressure diaphragm of the rapid release mechanism withstands 1.2 times the initial pressure of the high-pressure storage tank.

[0033] Step 4: The high-pressure gas expands through the Laval nozzle to form a high-pressure, high-speed jet, which is then injected into the test chamber;

[0034] Meanwhile, the measurement and control system collects and records data during the jet test in real time.

[0035] Further, in step 1, the initial pressure of the high-pressure storage tank is calculated and determined. The steps include:

[0036] Step S1.1: Calculate the momentum flux of the target rocket engine according to the formula. :

[0037]

[0038]

[0039] In the formula, The target is the Mach number of the gas exiting the rocket engine nozzle. It refers to the static temperature of the exhaust gas at the nozzle exit of the target rocket engine. The target rocket engine exit velocity, The gas constant of the engine combustion gas. It is the engine outlet gas flow rate; It is the gas constant of the engine combustion gas;

[0040] Step S1.2: Solve the equivalent total pressure based on numerical iteration :

[0041]

[0042]

[0043] In the formula, and These are the specific heat and gas constant of the high-pressure gas inside the high-pressure storage tank, respectively. To test the high-pressure gas velocity at the nozzle exit; It is the throat area of ​​the Laval nozzle. It is the initial temperature inside the high-pressure storage tank;

[0044] Step S1.3: Based on the equivalent total pressure Determine the initial pressure of the high-pressure storage tank. , The safety factor is set between 1.2 and 1.5.

[0045] Volume of high-pressure storage tank Determined in the following manner:

[0046] The high-pressure gas supply from the high-pressure storage tank needs to meet the jet test time requirement; therefore, the volume of the high-pressure storage tank... To satisfy:

[0047]

[0048]

[0049] In the formula, This represents the total gas consumption during the experiment.

[0050] Furthermore, the high-pressure gas is either air or nitrogen, or a mixture of the two.

[0051] The advantages of this invention are:

[0052] The rocket engine short-term high-pressure high-speed jet simulation device provided by this invention includes a high-pressure gas source, a high-pressure storage tank, a Laval nozzle, a rapid release mechanism, a sealed test chamber, and a measurement and control system. The rapid release mechanism is located inside the throat of the Laval nozzle and is used to seal and release the high-pressure gas (air and / or nitrogen) stored in the high-pressure storage tank. The measurement and control system controls the rapid release mechanism to perform the release action. The high-pressure gas passes through the Laval nozzle to generate a high-pressure high-speed jet, which acts on the test specimen in the test chamber, realizing the simulation of the high-pressure high-speed jet of the rocket engine. Compared with traditional devices and traditional simulation methods, this invention has the following significant advantages:

[0053] 1. Significantly improved safety: The use of cold airflow (cold air and / or nitrogen, without heating) to simulate the effects of propellant combustion avoids risks such as explosion, poisoning, and pollution, making the test process safer and more controllable;

[0054] 2. Flexible parameter adjustment: Only the pressure, volume, and gas type of the high-pressure storage tank need to be adjusted to simulate the jet flow conditions of rocket engines with different thrust levels and working durations, with good reproducibility and repeatability;

[0055] 3. Higher measurement accuracy: The jet medium in this invention uses pure air and / or nitrogen, and there are no carbon deposits or corrosion problems caused by combustion products after jetting, which ensures the long-term reliable operation of optical measurement and sensors.

[0056] 4. Accurate reproduction of core features: Based on the gas parameters and jet parameters of the target rocket engine, the pressure, volume and gas type of the high-pressure storage tank are calculated. This can effectively reproduce the core mechanical and acoustic load characteristics of real rocket jets, such as high pressure, high speed and high noise, providing key support for structural bearing capacity and acoustic and vibration environment adaptability assessment. Attached Figure Description

[0057] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0058] Figure 1 This is a schematic diagram of the overall connection of the rocket engine short-time high-pressure high-speed jet simulation device of the present invention;

[0059] Figure 2 This is a partially enlarged schematic diagram of the rapid release mechanism and the Laval nozzle in this invention;

[0060] Figure 3 This is a schematic diagram of the arrangement of the high-pressure diaphragm and the triggering device in the rapid release mechanism of the present invention;

[0061] In the diagram: 1-High-pressure gas source, 2-High-pressure storage tank, 3-Laval nozzle, 301-Nozzle contraction section, 302-Nozzle expansion section, 4-Rapid release mechanism, 401-Diaphragm fixing clamp, 402-High-pressure diaphragm, 403-Triggering device, 5-Test piece, 6-Test chamber, 7-Measurement and control system. Detailed Implementation

[0062] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0063] Example 1

[0064] Reference Figure 1 This embodiment provides a short-term high-pressure high-speed jet simulation system for a rocket engine, including a high-pressure gas source 1, a high-pressure storage tank 2, a Laval nozzle 3, a rapid release mechanism 4, an experimental chamber 6, and a measurement and control system 7.

[0065] In this embodiment, the high-pressure gas source 1 can be a large-displacement air compressor unit or a high-pressure gas cylinder group pre-filled with high-pressure inert gas (such as nitrogen or air). The high-pressure gas source 1 includes an air compressor and a gas booster pump. The high-pressure gas source 1 is connected to the inlet of the high-pressure storage tank 2 through a high-pressure pipeline, and is used to provide clean and stable high-pressure gas to the high-pressure storage tank 2.

[0066] High-pressure storage tank 2 is a pressure vessel capable of withstanding high pressure (e.g., 15-40 MPa), its volume determined by the required jet duration for the test. The outlet of high-pressure storage tank 2 is connected to the inlet of Laval nozzle 3 via a flange. An inflation valve is installed on the high-pressure pipeline, and high-pressure storage tank 2 is equipped with a pressure gauge and a safety valve to control the gas supply and initially adjust the output pressure for easy on-site monitoring, ensuring safe pressure storage.

[0067] The Laval nozzle 3 (i.e., the convergent-divergent nozzle) comprises a converging section 301 and a diverging section 302, employing a split structure. The inlet of the Laval nozzle 3 is sealed to the outlet of the high-pressure storage tank 2 via a flange. Its profile is precisely designed and machined according to the required Mach number for the test (e.g., Ma=2.0, 3.0, 4.0, etc.). Its material can be high-strength stainless steel or a high-temperature alloy to ensure its profile stability under the impact of high-pressure, high-speed airflow. The function of the Laval nozzle 3 is to convert the pressure energy of the high-pressure gas into kinetic energy, generating a jet that efficiently accelerates the airflow to supersonic speeds.

[0068] The rapid release mechanism 4 is located within the nozzle contraction section 301. In this embodiment, the rapid release mechanism 4 is located at the throat of the Laval nozzle 3, specifically at the junction of the nozzle contraction section 301 and the nozzle expansion section 302. Its core function is to rapidly open within a very short time (typically milliseconds) to form a large-area flow channel, thereby releasing the high-pressure gas within the high-pressure storage tank 2. The rapid release mechanism 4 includes a diaphragm fixing clamp 401, a high-pressure diaphragm 402, and a triggering device 403. The high-pressure diaphragm is located within the throat of the Laval nozzle 3, and its edges are clamped and fixed by the diaphragm fixing clamp 401, which can completely seal the high-pressure gas within the high-pressure storage tank.

[0069] Reference Figure 2 The diaphragm fixing clamp 401 includes a first connecting flange, a second connecting flange, and two clamp units. The first connecting flange is coaxially fixed to the docking port of the nozzle contraction section 301, and the second connecting flange is coaxially fixed to the docking port of the nozzle expansion section 302. The edge of the high-pressure diaphragm is clamped between the first connecting flange and the second connecting flange, and the first connecting flange and the second connecting flange are axially fixed by the two clamp units. Specifically, each clamp unit includes a first clamping body and a second clamping body that cooperate with each other. The sidewalls of the first clamping body and the second clamping body are provided with a first clamping portion and a second clamping portion that cooperate with each other. The first connecting flange and the second connecting flange are clamped between the first clamping portion and the second clamping portion. In this embodiment, the first clamping portion and the second clamping portion are rectangular block structures.

[0070] Reference Figure 3 The high-pressure diaphragm 402 has a pre-cut stress groove in its center, and the triggering device 403 is located at the stress groove position of the high-pressure diaphragm 402. In this embodiment, the triggering device 403 adopts an electric detonator drive circuit or a shaped charge lock, and its ignition control line is connected to the measurement and control system 7. The high-pressure diaphragm is selected according to the designed burst pressure value. In this embodiment, the pressure bearing capacity of the high-pressure diaphragm is 1.2 times the initial pressure of the high-pressure storage tank. When the triggering device receives the instruction (electrical signal) from the measurement and control system 7, the triggering device is activated, breaking the high-pressure diaphragm and realizing the instantaneous full-bore release of high-pressure gas.

[0071] Test chamber 7 is a sealed, rigid chamber with walls possessing sufficient strength and rigidity to withstand the reaction force and noise impact of the jet. The opening of test chamber 7 is equipped with a sealing flange for a secure connection to the outlet end of the Laval nozzle 3. High-strength observation windows are located on the sides of the chamber, facilitating the recording of the jet flow field and the specimen's response process by a high-speed camera. Multiple sensor interfaces and cable run-through connectors are provided at the top and rear of the chamber for the placement of measuring equipment. The bottom of the chamber can also be designed with flow guide channels and an exhaust system for the rapid discharge of gases after the test.

[0072] The test specimen 5 is fixed inside the test chamber 6 by a support clamp, with its test surface facing the exit of the Laval nozzle 3 to withstand the impact of the supersonic jet. The test specimen 5 can be a deflector, thermal protection material, or a model rocket body.

[0073] The measurement and control system 7 is the control and measurement center of the entire jet flow simulation system, adopting an architecture of industrial computer + PLC (Programmable Logic Controller) + data acquisition card. The measurement and control system includes a control unit, a measurement unit, a high-speed data acquisition instrument, a flow field display device, and a human-machine interface. The control unit is used to control the start and stop of the high-pressure gas source and to issue trigger commands to the rapid release mechanism 4.

[0074] The measurement unit includes at least a pressure sensor, an impact sensor, and an accelerometer. The pressure sensor is located inside the high-pressure storage tank 2 (monitoring the gas storage pressure), at the outlet of the Laval nozzle 3 (monitoring the jet pressure), and inside the test chamber 6 or on the surface of the test specimen (monitoring the impact pressure). The impact sensor is installed on the surface of the test specimen to obtain the impact force experienced by the specimen.

[0075] High-speed data acquisition instruments are used to synchronously acquire signals from all sensors at a high sampling rate (typically >10kHz) to ensure the capture of transient data during the jet build-up process.

[0076] The human-machine interface runs on an industrial computer and is used to set test parameters (pressure, volume, etc. of high-pressure storage tank), display pressure-time in real time, and store and replay test data.

[0077] The working process of simulating high-pressure, high-speed jet flow from a rocket engine according to the present invention is as follows:

[0078] Step 1: System preparation and parameter preset.

[0079] Based on the total pressure, total temperature, mass flow rate, and duration of the target rocket engine jet, the initial pressure of the high-pressure storage tank is calculated and set. Volume The invention employs various gas types (such as air, nitrogen, or a mixture of both in a specific ratio) to achieve the same mechanical impact effect as a rocket engine jet. The core objective of this invention is to reproduce the momentum flow rate of a real engine ignition jet to simulate the mechanical impact effect of the jet on surrounding equipment. Since ground tests typically use room-temperature gases (such as nitrogen, 300K) rather than the high-temperature combustion gases (thousands of K) of a real engine, the total pressure of the simulation system must be increased to compensate for the engine temperature difference in order to achieve the same momentum flow rate (impact force).

[0080] The initial pressure of the high-pressure storage tank is calculated and determined. The steps include:

[0081] First, calculate the momentum flux of the target rocket engine according to the formula. That is, based on the Mach number of the gas at the exit of the target rocket engine nozzle. and the static temperature of the gas at the nozzle exit of the target rocket engine Calculate the exit velocity of the target rocket engine. The calculation formula is:

[0082]

[0083]

[0084] In the formula, The target is the Mach number of the gas exiting the rocket engine nozzle. It refers to the static temperature of the exhaust gas at the nozzle exit of the target rocket engine. The target rocket engine exit velocity, The gas constant of the engine combustion gas. It is the engine outlet gas flow rate; It is the gas constant of the engine combustion gas.

[0085] Then, the equivalent total pressure is solved based on numerical iteration (such as Newton's method). The iterative calculation formula is:

[0086]

[0087]

[0088] In the formula, and These are the specific heat and gas constant of the high-pressure gas inside the high-pressure storage tank, respectively. It is the throat area of ​​the Laval nozzle. It is the initial temperature inside the high-pressure storage tank; To test the high-pressure gas velocity at the nozzle exit.

[0089] Next, based on the equivalent total pressure Determine the initial pressure of the high-pressure storage tank. To ensure stable flow rate during the test, the initial pressure of the storage tank must be higher than the equivalent total pressure. And consider the engineering safety factor (usually taken as 1.2 to 1.5 times): .

[0090] Determine the required volume of the high-pressure storage tank The high-pressure storage tank needs to provide sufficient gas volume to ensure the test duration. That is, the total gas consumption satisfies This embodiment uses a simplified estimate of the required volume of the high-pressure storage tank based on the ideal gas law and considering the available gas quantity. :

[0091]

[0092]

[0093] In the formula, This represents the initial temperature inside the high-pressure storage tank. It is the gas flow rate at the engine outlet.

[0094] Step 2: High-pressure gas filling and sealing.

[0095] Turn on the high-pressure gas source 1 and fill the high-pressure storage tank 2 with high-pressure gas heated to the preset pressure and temperature values. The high-pressure gas is sealed inside the high-pressure storage tank through the high-pressure diaphragm (bursting diaphragm) installed at the throat or telescoping section of the Laval nozzle. Install the test piece 5 into the test chamber.

[0096] Step 3: Triggering and Releasing Phase.

[0097] Once all parameters reach their preset values ​​and stabilize, the operator issues a trigger command through the monitoring and control system 7. The trigger device instantly ruptures the high-pressure diaphragm, which breaks within milliseconds, causing the high-pressure gas in the high-pressure storage tank to depressurize instantly and rush into the Laval nozzle 3.

[0098] The high-pressure diaphragm must withstand 1.2 times the initial pressure of the storage tank to ensure that it does not rupture under the initial pressure and can rupture reliably under the control of the initial pressure and the triggering device.

[0099] Step 4: The high-pressure gas expands and accelerates in the Laval nozzle 3, forming a supersonic jet that impacts the test component 5 (such as the deflector, thermal protection material, and model rocket body) inside the test chamber.

[0100] Step 5: During the jetting process, the measurement and control system 7 synchronously collects and records the jetting pressure, heat flow, temperature field and flow field structure data for subsequent analysis and verification.

[0101] After the gas in high-pressure storage tank 2 has been completely released, the jetting stops. The exhaust system of test chamber 6 is then activated, the test specimen or diaphragm is replaced, and preparation for the next test is made.

[0103] Example 2

[0104] To verify the reliability of simulating jet flow using the device of the present invention, Example 2 is illustrated using a jet flow simulation test of a small solid rocket engine as an example:

[0105] (1) Test objective: To simulate the jet environment of a small solid rocket engine working on the ground (lasting about 3 seconds), with a nozzle throat diameter of 50 mm and a flow rate of 50 kg / s;

[0106] (2) Parameter design: Dry air was selected as the simulation medium, and the volume of the high-pressure storage tank was determined by calculating the flow rate formula. It is 3.5 Initial pressure 15MPa (to compensate for total temperature loss);

[0107] (3) System preparation: Fill the high-pressure storage tank with dry air to 15MPa, install a diaphragm with a rated burst pressure of 18MPa at the throat of the Laval nozzle; fix the test piece at the preset distance from the nozzle outlet, and debug the high-speed camera and data acquisition system;

[0108] (4) Triggering and data acquisition: Send an electrical signal to trigger the electric detonator or shaped charge to break the diaphragm, and the high-pressure gas is released instantaneously, forming a supersonic jet that lasts for about 2.8 seconds; record the peak value and distribution of the impact pressure on the test piece surface through a pressure sensor, and capture the jet shock wave structure using a high-speed camera and schlieren system;

[0109] (5) Results verification: The experimental data of this invention are consistent with the results of traditional pure numerical CFD simulation, verifying that the test piece design can withstand the target level of impact environmental load and meet the requirements of engineering applications.

[0110] Through the above design, the jet simulation system designed in this invention can safely, reliably, and repeatedly simulate the generation of high-pressure supersonic jets in a ground laboratory environment, providing a critical test environment for thermal protection materials and structures in the aerospace field.

[0111] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A short-duration high-pressure, high-speed jet simulation system for a rocket engine, characterized in that, This includes a high-pressure gas source, a high-pressure storage tank, a Laval nozzle, a rapid release mechanism, a test chamber, and a measurement and control system; The high-pressure gas source is connected to the inlet of the high-pressure storage tank to provide high-pressure gas; The outlet of the high-pressure storage tank is connected to the inlet of the Laval nozzle, and the outlet of the Laval nozzle is sealed to the opening of the test chamber and faces the test piece placed inside the test chamber. The rapid release mechanism is installed inside the Laval nozzle and close to the outlet of the high-pressure storage tank; the rapid release mechanism is used to seal and release the high-pressure gas stored in the high-pressure storage tank, and to generate a high-pressure, high-speed jet when the gas is released. The measurement and control system is used to control the rapid release mechanism to perform the release action and monitor the test parameters.

2. The jet flow simulation device according to claim 1, characterized in that, The rapid release mechanism includes a high-pressure diaphragm, a triggering device, and a diaphragm fixing clamp. The high-pressure diaphragm is disposed inside the throat of the Laval nozzle, and its edge is clamped and fixed by the diaphragm fixing clamp, for sealing or releasing the high-pressure gas; The triggering device is disposed on the high-voltage diaphragm and is used to break the high-voltage diaphragm under the control of the measurement and control system to release the high-voltage gas.

3. The jet flow simulation device according to claim 2, characterized in that, The triggering device is an electric detonator drive circuit or a shaped charge lock.

4. The jet flow simulation device according to claim 3, characterized in that, The Laval nozzle is a split type, including a nozzle contraction section and a nozzle expansion section; The diaphragm fixing fixture includes a first connecting flange, a second connecting flange, and two fixture units; the first connecting flange is coaxially fixed to the docking port of the nozzle contraction section, and the second connecting flange is coaxially fixed to the docking port of the nozzle expansion section. The edge of the high-pressure diaphragm is clamped between the first connecting flange and the second connecting flange, and the first connecting flange and the second connecting flange are axially fixed by the two clamp units.

5. The jet flow simulation device according to claim 4, characterized in that, The clamp unit includes a first clamping body and a second clamping body that cooperate with each other, and the side walls of the first clamping body and the side walls of the second clamping body are provided with a first clamping part and a second clamping part that cooperate with each other. The first connecting flange and the second connecting flange are clamped between the first clamping part and the second clamping part.

6. The jet flow simulation device according to claim 1, characterized in that, The measurement and control system includes a control unit, a measurement unit, a high-speed data acquisition instrument, and a human-machine interface; The control unit is used to control the start and stop of the high-pressure gas source and to issue trigger commands to the rapid release mechanism; The measurement unit includes various sensors installed on the high-pressure storage tank, Laval nozzle, and test piece, which are used in conjunction with a high-speed data acquisition instrument to collect and record data during the jet flow test in real time. The human-computer interaction interface is used to set test parameters, view real-time test process data, and store and replay test data.

7. The jet flow simulation device according to claim 1, characterized in that, An inflation valve is installed on the high-pressure pipeline between the high-pressure gas source and the high-pressure storage tank. The high-pressure storage tank is equipped with a pressure gauge and a safety valve to detect pressure and ensure the safety of the storage pressure.

8. A method for simulating short-duration high-pressure, high-speed jet flow from a rocket engine, characterized in that, Based on the jet flow simulation device according to any one of claims 1-7; The jet simulation method includes the following steps: Step 1: Calculate and determine the initial pressure, volume, and filling type of the high-pressure storage tank based on the total pressure, total temperature, mass flow rate, and duration of the target rocket engine jet. Step 2: Install the test piece into the test chamber; start the high-pressure gas source and fill the high-pressure storage tank with high-pressure gas; at this time, the high-pressure gas is sealed inside the high-pressure storage tank; Step 3: Control the rapid release mechanism to release the high-pressure gas in the high-pressure storage tank; The high-pressure diaphragm of the rapid release mechanism is pressurized to 1.2 times the initial pressure of the high-pressure storage tank. Step 4: The high-pressure gas expands through the Laval nozzle to form a high-pressure, high-speed jet, which is then injected into the test chamber; Meanwhile, the measurement and control system collects and records data during the jet stream test in real time.

9. The jet simulation method according to claim 8, characterized in that, In step 1: The initial pressure of the high-pressure storage tank is calculated and determined. The steps include: Step S1.1: Calculate the momentum flux of the target rocket engine according to the formula. : In the formula, The target is the Mach number of the gas exiting the rocket engine nozzle. It refers to the static temperature of the exhaust gas at the nozzle exit of the target rocket engine. The target rocket engine exit velocity, The gas constant of the engine combustion gas. It is the engine outlet gas flow rate; It is the gas constant of the engine combustion gas; Step S1.2: Solve the equivalent total pressure based on numerical iteration : In the formula, and These are the specific heat and gas constant of the high-pressure gas inside the high-pressure storage tank, respectively. To test the high-pressure gas velocity at the nozzle exit; It is the throat area of ​​the Laval nozzle. It is the initial temperature inside the high-pressure storage tank; Step S1.3: Based on the equivalent total pressure Determine the initial pressure of the high-pressure storage tank. , The safety factor is set between 1.2 and 1.

5. The volume of the high-pressure storage tank Determined in the following manner: The high-pressure gas supply from the high-pressure storage tank needs to meet the jet test time requirement; therefore, the volume of the high-pressure storage tank... To satisfy: In the formula, This represents the total gas consumption during the experiment.

10. The jet simulation method according to claim 9, characterized in that, The high-pressure gas is either air or nitrogen, or a mixture of the two.

Images