An equivalent simulation test method for interstage thermal separation based on explosion shock

Abstract

The invention relates to an interstage thermal separation equivalent simulation test method based on explosion impact, belonging to the field of test technology; according to mass and energy conservation equations, an initial corresponding relationship between and flow parameters is established; an advanced corresponding relationship between and flow parameters is obtained; a calculation formula of and is established; a relationship equation of the explosion shock tube explosion equivalent to replacing rocket engine combustion is established; according to the relationship equation of the explosion shock tube explosion equivalent to replacing rocket engine combustion, the unknown parameters are solved, and the parameters are adjusted according to the solution results to achieve the jet effect produced by the explosion shock tube explosion equivalent to replacing rocket engine combustion; the invention realizes the equivalent of the pulsating pressure effect at different positions in the interstage section in the process of simulating engine operation by modulating the initial parameters of the explosion shock tube.

Description

Technical Field

[0001] The invention belongs to the field of test technology and relates to an inter-stage thermal separation equivalent simulation test method based on explosion impact. Background Art

[0002] During the rocket development process, it is necessary to verify the reliability of the separation scheme between the first and second stage rockets to ensure that the first and second stage rockets can be separated smoothly under the predetermined timing and conditions, and the separation process will not affect the subsequent flight.

[0003] Currently, the verification of the rocket interstage separation process is mainly carried out through the engine three-in-one test. That is, while assessing and verifying the working reliability of the second-stage engine, the lower stage and interstage are installed at the rear end of the engine. After the engine is ignited, a series of instructions are used to implement the assessment and verification of the actual interstage separation process.

[0004] The traditional three-in-one ground test of engines uses actual engine ignition for testing, resulting in high test costs, long test cycles and poor repeatability. Currently, the traditional three-in-one ground test of engines is mainly used to evaluate the interstage separation process, and is not suitable for process verification and rapid iteration of solutions for some new interstage separation methods. Summary of the invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and propose an interstage thermal separation equivalent simulation test method based on explosion shock, by modulating the initial parameters of the explosion shock tube, to achieve the equivalent effect of the pulsating pressure at different positions in the interstage section during the simulation of engine operation.

[0006] The solution of the present invention is:

[0007] An interstage thermal separation equivalent simulation test method based on explosion shock, comprising:

[0008] Under normal working conditions, the jet generated by the rocket engine combustion acts on the interstage of the rocket. When the pressure in the interstage of the rocket is built up, the pressure variable over time is ; According to the mass and energy conservation equations, establish Initial correspondence with flow parameters;

[0009] The explosion of the explosion shock tube is used to replace the combustion of the rocket engine to generate a jet to act on the interstage of the rocket; according to the actual physical parameters of the explosion shock tube and the rocket engine, the flow parameters are simplified and simplified. The initial correspondence between and flow parameters; get Advanced correspondence with flow parameters;

[0010] The total pressure generated by the explosion of the shock tube is assumed to be The total temperature generated by the explosion of the shock tube is ;Establish and The calculation formula of

[0011] according to Advanced correspondence with flow parameters, , , establish the relationship equation that the explosion of the shock tube is equivalent to the combustion of the rocket engine;

[0012] According to the relationship equation that the explosion of the explosive shock tube is equivalent to the combustion of the rocket engine, the unknown parameters are solved, and the parameters are adjusted according to the solution results to achieve the jet effect produced by the explosion of the explosive shock tube equivalent to the combustion of the rocket engine.

[0013] In the above-mentioned interstage heat separation equivalent simulation test method based on explosion impact, the flow parameters include the interstage gas heat loss coefficient , Engine gas specific heat ratio , nozzle throat cross-sectional area , Interstage volume , Engine gas constant pressure specific heat , Engine gas total pressure , Engine gas total temperature and the fuel gas constant .

[0014] In the above-mentioned interstage thermal separation equivalent simulation test method based on explosion shock, the The initial correspondence between and flow parameters is:

[0015] .

[0016] In the above-mentioned interstage heat separation equivalent simulation test method based on explosion shock, among the physical parameters of the explosion shock tube and the rocket engine, the intermediate gas heat loss coefficient , Engine gas specific heat ratio , nozzle throat cross-sectional area , Interstage volume , Engine gas constant pressure specific heat and the fuel gas constant are the same, so the above parameters are simplified.

[0017] In the above-mentioned interstage thermal separation equivalent simulation test method based on explosion shock, the The advanced correspondence between the flow parameters is:

[0018]

[0019] In the formula, Only indicates and There is an equation relationship, but the specific equation form is not considered.

[0020] In the above-mentioned interstage thermal separation equivalent simulation test method based on explosion shock, the total pressure generated by the explosion shock tube explosion is Including the pressure generated by the explosion of explosives in the explosion shock tube and the pressure of the additional high pressure gas input ,Right now for:

[0021] .

[0022] In the above-mentioned interstage thermal separation equivalent simulation test method based on explosion shock, the total temperature generated by the explosion shock tube explosion is Including the temperature generated by the explosion of explosives in the explosion shock tube and the temperature of the additional high pressure gas input ,Right now for:

[0023] .

[0024] In the above-mentioned interstage thermal separation equivalent simulation test method based on explosion shock, when When the explosion is completed, the explosion of the shock tube is equivalent to replacing the combustion of the rocket engine.

[0025] In the above-mentioned interstage thermal separation equivalent simulation test method based on explosion shock, Refine to:

[0026]

[0027] Among them, according to the actual working conditions, the total pressure of engine gas and engine gas total temperature are all known; according to the charge in the explosion shock tube, and are all known; the temperature of the additional high-pressure gas input is known; that is, the unknown parameters are solved according to the equation .

[0028] In the above-mentioned interstage thermal separation equivalent simulation test method based on explosion shock, the pressure of the additional input high-pressure gas is adjusted to , that is, the explosion of the explosive shock tube is equivalent to replacing the jet effect produced by the combustion of the rocket engine.

[0029] The beneficial effects of the present invention compared with the prior art are:

[0030] (1) The present invention uses an explosive shock tube instead of a rocket engine to test the internal structural strength of the rocket's interstage and the interstage separation process, which can significantly reduce test costs and shorten test cycles. It provides a better test platform for the rapid iteration and verification of some new interstage separation schemes;

[0031] (2) Compared with the wind tunnel test, the explosion shock tube of the present invention can conduct full-scale ground tests on the interstage section, especially the structural strength assessment can directly verify the rationality of the structure in the interstage section, and its cost is also much lower than the wind tunnel test;

[0032] (3) The present invention can ensure that the pulsating pressure effect of the explosion shock tube on the interstage section is basically consistent with that of the rocket engine through the above modulation method, thereby ensuring the effectiveness of the explosion shock tube in assessing the structural strength of the interstage section casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a flow chart of an equivalent simulation test of interstage thermal separation based on an explosion shock tube according to the present invention;

[0034] Figure 2 A schematic diagram of parameter modulation results of an embodiment of the present invention;

[0035] Figure 3 This is a flow simulation analysis result diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the embodiments.

[0037] The present invention provides an interstage thermal separation equivalent simulation test method based on explosion shock, wherein the device used for explosion shock in the present invention is an explosion shock tube. The explosion shock tube generates shock wave load to simulate the working process of the rocket engine, and conducts the structural strength assessment of the rocket interstage section and the verification test of the interstage separation scheme.

[0038] The explosion shock tube itself has the advantages of low cost, short cycle and good repeatability. The main technical problem is how to modulate the initial parameters of the explosion shock tube so that it can achieve equivalent effects on the pulsating pressure at different positions in the interstage during the simulation of engine operation.

[0039] The equivalent simulation test method of interstage thermal separation based on explosion shock tube, such as Figure 1 As shown, the specific steps include:

[0040] Under normal working conditions, the jet generated by the rocket engine combustion acts on the interstage of the rocket. When the pressure in the interstage of the rocket is built up, the pressure variable over time is ; According to the mass and energy conservation equations, establish The initial correspondence between the flow parameters.

[0041] Flow parameters include interstage gas heat loss coefficient , Engine gas specific heat ratio , nozzle throat cross-sectional area , Interstage volume , Engine gas constant pressure specific heat , Engine gas total pressure , Engine gas total temperature and the fuel gas constant .

[0042] Description The initial correspondence between and flow parameters is:

[0043] .

[0044] The explosion of the explosion shock tube is used to replace the combustion of the rocket engine to generate a jet to act on the interstage of the rocket; according to the actual physical parameters of the explosion shock tube and the rocket engine, the flow parameters are simplified and simplified. The initial correspondence between and flow parameters; get Advanced correspondence with flow parameters.

[0045] Due to the physical parameters of the explosion shock tube and the rocket engine, the intermediate gas heat loss coefficient , Engine gas specific heat ratio , nozzle throat cross-sectional area , Interstage volume , Engine gas constant pressure specific heat and the fuel gas constant are the same, so the above parameters are simplified.

[0046] but The advanced correspondence between the flow parameters is:

[0047]

[0048] In the formula, Only indicates and There is an equation relationship, but the specific equation form is not considered.

[0049] The total pressure generated by the explosion of the shock tube is assumed to be The total temperature generated by the explosion of the shock tube is ;Establish and The calculation formula for .

[0050] The total pressure generated by the explosion of the shock tube Including the pressure generated by the explosion of explosives in the explosion shock tube and the pressure of the additional high pressure gas input ,Right now for:

[0051] .

[0052] The total temperature generated by the explosion of the shock tube is Including the temperature generated by the explosion of explosives in the explosion shock tube and the temperature of the additional high pressure gas input ,Right now for:

[0053] .

[0054] according to Advanced correspondence with flow parameters, , , establish the relationship equation that the explosion of the shock tube is equivalent to the combustion of the rocket engine.

[0055] when When the explosion is completed, the explosion of the shock tube is equivalent to replacing the combustion of the rocket engine.

[0056] According to the relationship equation that the explosion of the explosive shock tube is equivalent to the combustion of the rocket engine, the unknown parameters are solved, and the parameters are adjusted according to the solution results to achieve the jet effect produced by the explosion of the explosive shock tube equivalent to the combustion of the rocket engine.

[0057] Will Refine to:

[0058]

[0059] Among them, according to the actual working conditions, the total pressure of engine gas and engine gas total temperature are all known; according to the charge in the explosion shock tube, and are all known; the temperature of the additional high-pressure gas input is known; that is, the unknown parameters are solved according to the equation .

[0060] Adjust the pressure of the additional high-pressure gas to , that is, the explosion of the explosive shock tube is equivalent to replacing the jet effect produced by the combustion of the rocket engine.

[0061] Example

[0062] For example, in the initial stage of a certain type of rocket engine, the total pressure in the combustion chamber is in the rising stage. Within 10ms, the total pressure rises from 2.7MPa to 3.3MPa, the average total pressure is 3.0MPa, and the total temperature is 3500K. For a certain type of explosion shock tube, a total temperature of 1500K can be achieved under a certain charge amount. According to the above theoretical model, an average total pressure of 4.8MPa is required. However, the current type of explosive can only produce a total pressure corresponding to 3.3MPa, so an additional 1.5MPa of high-pressure gas is introduced to make it reach the theoretical state. See the specific parameter modulation results for details. Figure 2 .

[0063] The above theoretical analysis results are analyzed by flow simulation. The specific simulation results are shown in Figure 3 The average pressure changes in the interstage section under the two states are basically the same, while there are certain differences in the unsteady pressure changes at the characteristic positions, mainly due to the difference in flow velocity caused by the different total temperatures, that is, the time of the explosion shock tube acting on the pressure in the interstage section has an obvious lag of about 0.5ms compared with the rocket engine, but the size of the pressure peak and the pulse width are basically the same. Since the lag phenomenon has no decisive influence on the assessment of the structural strength in the interstage section, the equivalence of using the explosion shock tube to assess the interstage structural strength is demonstrated.

[0064] The present invention uses an explosive shock tube instead of a rocket engine to test the internal structural strength of the rocket's interstage section and the interstage separation process, which can significantly reduce test costs and shorten test cycles, and provides a better test platform for the rapid iteration and verification of some new interstage separation schemes.

[0065] Compared with the wind tunnel test, the explosion shock tube of the present invention can carry out full-scale ground test on the interstage section, especially the structural strength assessment can directly verify the rationality of the structure in the interstage section, and the cost is also much lower than the wind tunnel test.

[0066] The present invention can ensure that the pulsating pressure effect of the explosion shock tube on the interstage section is basically consistent with that of the rocket engine through the above modulation method, thereby ensuring the effectiveness of the explosion shock tube in assessing the structural strength of the interstage section casing.

[0067] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An equivalent simulation test method for interstage thermal separation based on explosion shock, characterized in that: include: Under normal working conditions, the jet generated by the rocket engine combustion acts on the interstage of the rocket. When the pressure in the interstage of the rocket is built up, the pressure variable over time is ; According to the mass and energy conservation equations, establish Initial correspondence with flow parameters; The explosion of the explosion shock tube is used to replace the combustion of the rocket engine to generate a jet to act on the interstage of the rocket; according to the actual physical parameters of the explosion shock tube and the rocket engine, the flow parameters are simplified and simplified. The initial correspondence between and flow parameters; get Advanced correspondence with flow parameters; The total pressure generated by the explosion of the shock tube is assumed to be The total temperature generated by the explosion of the shock tube is ;Establish and The calculation formula of according to Advanced correspondence with flow parameters, , , establish the relationship equation that the explosion of the shock tube is equivalent to the combustion of the rocket engine; According to the relationship equation that the explosion of the explosive shock tube is equivalent to the combustion of the rocket engine, the unknown parameters are solved, and the parameters are adjusted according to the solution results to achieve the jet effect produced by the explosion of the explosive shock tube equivalent to the combustion of the rocket engine.

2. The method for equivalent simulation test of interstage thermal separation based on explosion shock according to claim 1 is characterized in that: The flow parameters include the inter-stage gas heat loss coefficient , Engine gas specific heat ratio , nozzle throat cross-sectional area , Interstage volume , Engine gas constant pressure specific heat , Engine gas total pressure , Engine gas total temperature and the fuel gas constant .

3. The interstage thermal separation equivalent simulation test method based on explosion impact according to claim 2 is characterized in that: Said The initial correspondence between and flow parameters is: 。 4. The interstage thermal separation equivalent simulation test method based on explosion impact according to claim 3 is characterized in that: Among the physical parameters of the explosion shock tube and rocket engine, the interstage gas heat loss coefficient , Engine gas specific heat ratio , nozzle throat cross-sectional area , Interstage volume , Engine gas constant pressure specific heat and the fuel gas constant are the same.

5. The interstage thermal separation equivalent simulation test method based on explosion impact according to claim 3 is characterized in that: Said The advanced correspondence between the flow parameters is: In the formula, Only indicates and Has equation relationship.

6. The method for simulating the equivalent interstage thermal separation based on explosion shock according to claim 5 is characterized in that: The total pressure generated by the explosion of the explosion shock tube Including the pressure generated by the explosion of explosives in the explosion shock tube and the pressure of the additional high pressure gas input ,Right now for:, 。 7. The interstage thermal separation equivalent simulation test method based on explosion shock according to claim 6 is characterized in that: The total temperature generated by the explosion of the explosion shock tube is Including the temperature generated by the explosion of explosives in the explosion shock tube and the temperature of the additional high pressure gas input ,Right now for: 。 8. The interstage thermal separation equivalent simulation test method based on explosion shock according to claim 7 is characterized in that: when When the explosion is completed, the explosion of the shock tube is equivalent to replacing the combustion of the rocket engine.

9. The interstage thermal separation equivalent simulation test method based on explosion shock according to claim 8 is characterized in that: Will Refine to: Among them, according to the actual working conditions, the total pressure of engine gas and engine gas total temperature are all known; according to the charge in the explosion shock tube, and are all known; the temperature of the additional high-pressure gas input is known; that is, the unknown parameters are solved according to the equation .

10. The interstage thermal separation equivalent simulation test method based on explosion shock according to claim 9 is characterized in that: Adjust the pressure of the additional high-pressure gas to , that is, the explosion of the explosive shock tube is equivalent to replacing the jet effect produced by the combustion of the rocket engine.

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