A method and apparatus for determining pipe shock wave pressure

Abstract

The application belongs to the technical field of data processing, and particularly relates to a pipeline shock wave pressure determination method and device. The method comprises the following steps: S1, determining an initiation point position of a launch object after chemical energy release is completed; S2, determining a distance between a calculation point of shock wave pressure to be calculated and the initiation point, a propagation speed of a detonation wave front generated at the initiation point position, specific internal energy and specific volume of a shock wave medium after chemical energy release; and S3, calculating the shock wave pressure. The application improves the calculation precision of the shock wave pressure.

Description

Technical Field

[0001] This application belongs to the field of data processing technology, specifically relating to a method and apparatus for determining pipeline shock wave pressure. Background Technology

[0002] The products launched within a designated conduit first explode at the detonation point, forming explosive products. The flow field at the firing muzzle of the conduit is unsteady, turbulent, multiphase, and directional, accompanied by chemical reactions. Essentially, this firing process involves an energy body rapidly releasing energy and transferring it to a specific device and the space within the firing barrel. Once detonated, the energy body first undergoes an explosive reaction at the detonation point, generating a large amount of high-temperature, high-pressure, and high-speed gas flow, which in turn generates a shock wave within the energy body. The shock wave intensely compresses adjacent thin layers, causing reactions that produce a large amount of gas and heat. From this point, the exit shock wave enters a phase of propagation relying on its own energy, and the attenuation trend of the far-field shock wave is similar to that of an equivalent explosive detonation. Although similar theoretical solutions for shock waves under specific conditions exist, they are difficult to apply to the analysis of specific problems.

[0003] Based on the characteristics of various devices, various simplified simulation methods for shock waves have been proposed in engineering, such as the standard shock wave load simulation method and the average pressure simulation method, but none of them are suitable for calculating the shock wave pressure in a specified pipeline. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a method and apparatus for determining pipeline shock wave pressure.

[0005] The first aspect of this application provides a method for determining the shock wave pressure in a pipeline, mainly including:

[0006] Step S1: Determine the location of the detonation point where the projectile completes the release of chemical energy;

[0007] Step S2: Determine the distance L from the calculation point of the shock wave pressure to be calculated to the detonation point, the propagation velocity D of the detonation wave front generated at the detonation point, and the specific internal energy of the shock wave medium after the release of chemical energy. and specific volume ;

[0008] Step S3: Calculate the shock wave pressure P according to the following formula:

[0009] ;

[0010] Where T is the detonation time, A, B, , , This represents the correlation coefficient of explosives.

[0011] Preferably, in step S2, the propagation velocity D of the detonation wave front is determined as follows:

[0012] ;

[0013] in, Let be the velocity of the shock wave medium after the release of chemical energy, and C be the local speed of sound.

[0014] Preferably, in step S4, step S3 further includes determining the explosive correlation coefficient through a cylinder test, wherein the cylinder test includes:

[0015] Step S31: Load the explosive to be tested into a copper tube, detonate one end, and record the movement trajectory of the outer diameter of the copper tube with a high-speed camera to obtain experimental control data;

[0016] Step S32: First determine a set of coefficients in the simulation calculation. , , Substitute the parameters into the JWL state equation to obtain the coefficients A and B. Then, substitute the obtained parameters into the numerical simulation of the cylindrical experiment to simulate the expansion trajectory of the outer diameter of the cylindrical tube driven by the explosive. Compare the simulation results with the experimental results.

[0017] Step S33: If the calculated cylinder wall velocity differs from the experimental value by no more than a threshold, then the assumed parameters are the true JWL equation parameters; otherwise, a new set of coefficients is selected. , , Then, recalculate the coefficients A and B, and perform simulations again until the error conditions are met.

[0018] Preferably, the threshold is 0.1.

[0019] The second aspect of this application provides a device for determining the pressure of a pipeline shock wave, mainly comprising:

[0020] The detonation point location determination module is used to determine the detonation point location of the projectile after it has completed the release of chemical energy;

[0021] The explosive parameter determination module is used to determine the distance L between the calculation point for the shock wave pressure to be calculated and the detonation point, the propagation velocity D of the detonation wave front generated at the detonation point, and the specific internal energy of the shock wave medium after the release of chemical energy. and specific volume ;

[0022] The shock wave pressure calculation module is used to calculate the shock wave pressure P according to the following formula:

[0023] ;

[0024] Where T is the detonation time, A, B, , , This represents the correlation coefficient of explosives.

[0025] Preferably, in the explosive parameter determination module, the propagation velocity D of the detonation wave front is determined as follows:

[0026] ;

[0027] in, Let be the velocity of the shock wave medium after the release of chemical energy, and C be the local speed of sound.

[0028] Preferably, the shock wave pressure calculation module further includes determining the explosive correlation coefficient through a cylindrical test, wherein the cylindrical test includes:

[0029] The experimental control data acquisition unit is used to load the explosive to be tested into a copper tube, detonate at one end, and use a high-speed camera to record the movement trajectory of the outer diameter of the copper tube to obtain experimental control data.

[0030] The simulation result comparison unit is used to determine a set of coefficients in the simulation calculation. , , Substitute the parameters into the JWL state equation to obtain the coefficients A and B. Then, substitute the obtained parameters into the numerical simulation of the cylindrical experiment to simulate the expansion trajectory of the outer diameter of the cylindrical tube driven by the explosive. Compare the simulation results with the experimental results.

[0031] The coefficient update unit is used to assume that the calculated cylinder wall velocity differs from the experimental value by no more than a threshold, in which case the parameters are the true JWL equation parameters; otherwise, a new set of coefficients is selected. , , Then, recalculate the coefficients A and B, and perform simulations again until the error conditions are met.

[0032] Preferably, the threshold is 0.1.

[0033] This application improves the accuracy of shock wave pressure calculation. Attached Figure Description

[0034] Figure 1 This is a flowchart of a preferred embodiment of the pipeline shock wave pressure determination method of this application.

[0035] Figure 2 This is a schematic diagram showing the relationship between the physical quantities of detonation products and the physical quantities of explosives.

[0036] Figure 3 This is a schematic diagram of a shock wave pressure simulation. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments of this application, not all of them. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0038] The first aspect of this application provides a method for determining the shock wave pressure in a pipeline, such as... Figure 1 As shown, it mainly includes:

[0039] Step S1: Determine the location of the detonation point where the projectile completes the release of chemical energy;

[0040] Step S2: Determine the distance L from the calculation point of the shock wave pressure to be calculated to the detonation point, the propagation velocity D of the detonation wave front generated at the detonation point, and the specific internal energy of the shock wave medium after the release of chemical energy. and specific volume ;

[0041] Step S3: Calculate the shock wave pressure P according to the following formula:

[0042] ;

[0043] Where T is the detonation time, A, B, , , This represents the correlation coefficient of explosives.

[0044] In some alternative implementations, in step S2, the propagation velocity D of the detonation wave front is determined as:

[0045] ;

[0046] in, Let be the velocity of the shock wave medium after the release of chemical energy, and C be the local speed of sound.

[0047] The method for calculating shock wave pressure provided in this application is based on the detonation wave theory of equivalent explosive explosion. The JWL equation of state is used to describe the detonation products of equivalent explosive. First, according to the law of shock wave in pipeline flow field, it is determined that the shock wave mainly occurs in the far field stage. The attenuation trend of the far field shock wave is similar to the characteristics of the shock wave of equivalent explosive explosion. Second, this application uses the detonation wave generated after equivalent explosive explosion to simulate the formation of pipeline shock wave. It is assumed that the explosive element completes the release of chemical energy and transforms into thermodynamically balanced detonation products instantaneously when passing through the detonation wave front. Based on the fact that when the detonation wave front propagates at the speed of shock wave, the physical quantities of explosive and the state of detonation products before and after it are uniform, and the physical quantities of explosive and detonation products on both sides of the front satisfy the mass, momentum and energy conservation relationship, the relationship between the physical quantities of detonation products and the physical quantities of explosive is obtained, namely the Rankine-Hugoniot (HR) relationship and the Chapman-Jouguet (CJ) model.

[0048] like Figure 2 As shown, assuming the detonation wave front propagates at the shock wave velocity D, the relationship between the physical quantities of the detonation products and the physical quantities of the explosive, i.e., the RH relationship, can be obtained using the conservation of mass, momentum, and energy:

[0049] ;

[0050] ;

[0051] ;

[0052] In the formula, D is the velocity of the shock wave. , , and These represent the velocity, density, pressure, and specific internal energy of the shock wave medium, respectively. 0、 0、 and This represents the initial velocity, initial density, initial pressure, and initial specific internal energy of the shock wave medium. Values ​​with and without subscripts indicate the values ​​before and after the shock wave, respectively.

[0053] Take the volume ratio: From the mass-momentum relationship, the Rayleigh line equation can be obtained:

[0054] ;

[0055] ;

[0056] In the formula For specific volume, This represents the initial specific volume.

[0057] From this, we can deduce that:

[0058] ;

[0059] .

[0060] Furthermore, the local speed of sound C is given by the formula:

[0061] ;

[0062] This leads to the classic CJ model of the detonation wave in an equivalent explosive explosion:

[0063] .

[0064] Subsequently, by obtaining the classical CJ ​​model of the detonation wave of the equivalent explosive explosion, the standard JWL equation of state for the detonation products was derived.

[0065] The isentropic lines of the CJ model are known. Internal energy yes:

[0066] ;

[0067] .

[0068] The equation is:

[0069] ;

[0070] Based on this, the standard JWL equation of state for detonation products can be obtained:

[0071] .

[0072] Therefore, it can be deduced that the shock wave pressure at different muzzle distances is determined based on the distance of each point on the explosive from the detonation point and the detonation velocity of the explosive:

[0073] .

[0074] In some alternative embodiments, step S3 further includes determining the explosive correlation coefficient through a cylinder test in step S4, wherein the cylinder test includes:

[0075] Step S31: Load the explosive to be tested into a copper tube, detonate one end, and record the movement trajectory of the outer diameter of the copper tube with a high-speed camera to obtain experimental control data;

[0076] Step S32: First determine a set of coefficients in the simulation calculation. , , Substitute the parameters into the JWL state equation to obtain the coefficients A and B. Then, substitute the obtained parameters into the numerical simulation of the cylindrical experiment to simulate the expansion trajectory of the outer diameter of the cylindrical tube driven by the explosive. Compare the simulation results with the experimental results.

[0077] Step S33: If the calculated cylinder wall velocity differs from the experimental value by no more than a threshold, then the assumed parameters are the true JWL equation parameters; otherwise, a new set of coefficients is selected. , , Then, recalculate the coefficients A and B, and perform simulations again until the error conditions are met.

[0078] In some alternative implementations, the threshold is 0.1.

[0079] This application, based on the theory of detonation waves, uses the JWL equation of state to describe the detonation products of equivalent explosives. Following the concept of cylindrical experiments, simulation methods are used to discuss the influence of various coefficients in the JWL equations on the shock wave pressure, and a set of simulation coefficients suitable for artillery-fired shock waves is finally determined. Then, a pipeline shock wave formation and propagation process simulated using equivalent explosives is established. Based on the parameters of the energy similarity law equivalence method, a finite element model of the shock wave is established. The shock wave pressure at a specified distance from each point on the explosive is determined based on the distance from the detonation point and the explosive detonation velocity. Figure 3 As shown.

[0080] A second aspect of this application provides a pipeline shock wave pressure determination device corresponding to the above method, mainly comprising:

[0081] The detonation point location determination module is used to determine the detonation point location of the projectile after it has completed the release of chemical energy;

[0082] The explosive parameter determination module is used to determine the distance L between the calculation point for the shock wave pressure to be calculated and the detonation point, the propagation velocity D of the detonation wave front generated at the detonation point, and the specific internal energy of the shock wave medium after the release of chemical energy. and specific volume ;

[0083] The shock wave pressure calculation module is used to calculate the shock wave pressure P according to the following formula:

[0084] ;

[0085] Where T is the detonation time, A, B, , , This represents the correlation coefficient of explosives.

[0086] In some optional embodiments, the propagation velocity D of the detonation wave front is determined in the explosive parameter determination module as follows:

[0087] ;

[0088] in, Let be the velocity of the shock wave medium after the release of chemical energy, and C be the local speed of sound.

[0089] In some alternative embodiments, the shock wave pressure calculation module further includes determining the explosive correlation coefficient through a cylindrical test, the cylindrical test comprising:

[0090] The experimental control data acquisition unit is used to load the explosive to be tested into a copper tube, detonate at one end, and use a high-speed camera to record the movement trajectory of the outer diameter of the copper tube to obtain experimental control data.

[0091] The simulation result comparison unit is used to determine a set of coefficients in the simulation calculation. , , Substitute the parameters into the JWL state equation to obtain the coefficients A and B. Then, substitute the obtained parameters into the numerical simulation of the cylindrical experiment to simulate the expansion trajectory of the outer diameter of the cylindrical tube driven by the explosive. Compare the simulation results with the experimental results.

[0092] The coefficient update unit is used to assume that the calculated cylinder wall velocity differs from the experimental value by no more than a threshold, in which case the parameters are the true JWL equation parameters; otherwise, a new set of coefficients is selected. , , Then, recalculate the coefficients A and B, and perform simulations again until the error conditions are met.

[0093] In some alternative implementations, the threshold is 0.1.

[0094] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining the pressure of a pipeline shock wave, characterized in that, include: Step S1: Determine the location of the detonation point where the projectile completes the release of chemical energy; Step S2: Determine the distance L from the calculation point of the shock wave pressure to be calculated to the detonation point, the propagation velocity D of the detonation wave front generated at the detonation point, and the specific internal energy of the shock wave medium after the release of chemical energy. and specific volume ; Step S3: Calculate the shock wave pressure P according to the following formula: ； Where T is the detonation time, A, B, , , This represents the correlation coefficient of explosives.

2. The method for determining pipeline shock wave pressure as described in claim 1, characterized in that, In step S2, the propagation velocity D of the detonation wave front is determined as follows: ； in, Let be the velocity of the shock wave medium after the release of chemical energy, and C be the local speed of sound.

3. The method for determining pipeline shock wave pressure as described in claim 1, characterized in that, In step S4, step S3 further includes determining the correlation coefficient of the explosive through a cylindrical test, wherein the cylindrical test includes: Step S31: Load the explosive to be tested into a copper tube, detonate one end, and record the movement trajectory of the outer diameter of the copper tube with a high-speed camera to obtain experimental control data; Step S32: First determine a set of coefficients in the simulation calculation. , , Substitute the parameters into the JWL state equation to obtain the coefficients A and B. Then, substitute the obtained parameters into the numerical simulation of the cylindrical experiment to simulate the expansion trajectory of the outer diameter of the cylindrical tube driven by the explosive. Compare the simulation results with the experimental results. Step S33: If the calculated cylinder wall velocity differs from the experimental value by no more than a threshold, then the assumed parameters are the true JWL equation parameters; otherwise, a new set of coefficients is selected. , , Then, recalculate the coefficients A and B, and perform simulations again until the error conditions are met.

4. The method for determining pipeline shock wave pressure as described in claim 3, characterized in that, The threshold is 0.

1.

5. A device for determining the pressure of a pipeline shock wave, characterized in that, include: The detonation point location determination module is used to determine the detonation point location of the projectile after it has completed the release of chemical energy; The explosive parameter determination module is used to determine the distance L between the calculation point for the shock wave pressure to be calculated and the detonation point, the propagation velocity D of the detonation wave front generated at the detonation point, and the specific internal energy of the shock wave medium after the release of chemical energy. and specific volume ; The shock wave pressure calculation module is used to calculate the shock wave pressure P according to the following formula: ； Where T is the detonation time, A, B, , , This represents the correlation coefficient of explosives.

6. The pipeline shock wave pressure determination device as described in claim 5, characterized in that, In the explosive parameter determination module, the propagation velocity D of the detonation wave front is determined as follows: ； in, Let be the velocity of the shock wave medium after the release of chemical energy, and C be the local speed of sound.

7. The pipeline shock wave pressure determination device as described in claim 5, characterized in that, In step S4, the shock wave pressure calculation module further includes determining the explosive correlation coefficient through a cylindrical test, wherein the cylindrical test includes: The experimental control data acquisition unit is used to load the explosive to be tested into a copper tube, detonate at one end, and use a high-speed camera to record the movement trajectory of the outer diameter of the copper tube to obtain experimental control data. The simulation result comparison unit is used to determine a set of coefficients in the simulation calculation. , , Substitute the parameters into the JWL state equation to obtain the coefficients A and B. Then, substitute the obtained parameters into the numerical simulation of the cylindrical experiment to simulate the expansion trajectory of the outer diameter of the cylindrical tube driven by the explosive. Compare the simulation results with the experimental results. The coefficient update unit is used to assume that the calculated cylinder wall velocity differs from the experimental value by no more than a threshold, in which case the parameters are the true JWL equation parameters; otherwise, a new set of coefficients is selected. , , Then, recalculate the coefficients A and B, and perform simulations again until the error conditions are met.

8. The pipeline shock wave pressure determination device as described in claim 7, characterized in that, The threshold is 0.1.

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