An optimization method for a multi-gas generator with variable-depth emission

Abstract

An optimization method for a multi-gas generator with variable-depth launch, which is disclosed by the present invention, belongs to the field of weapon launch. The implementation method of the present invention is as follows: According to the load launch constraint conditions and index requirements, optimize the loading conditions, nozzle throat diameter and the number of gas generators, so that a load with a specified mass, diameter and length can obtain a specified muzzle velocity under different launch depth conditions, and the acceleration of the load in the launch tube does not exceed the allowable value; flexibly adjust the number of working gas generators according to the variable-depth range to achieve variable-depth launch in a wide range; the synchronous ignition of the gas generators can avoid multiple pressure peaks generated during sequential ignition, and the load velocity increases steadily during the overall ejection process; the charge with area-increasing combustion adopts time-matching design to reduce the pressure peak value and narrow the deviation range of the load muzzle velocity. The multi-gas generator with variable-depth launch includes a launch tube, a load, a gas generator group, a gas generator, a nozzle, a circular plug, a charge and an ignition charge.

Description

Technical Field

[0001] The invention discloses an optimization method for a multi-gas generator for variable depth launch, belonging to the field of weapon launch. Background Art

[0002] Variable depth launch means that submarines or underwater platforms can launch torpedoes or missiles at different underwater depths. The use of variable depth launch is of great significance to improving the rapid response capability and battlefield survivability of submarines. On the one hand, submarines can flexibly choose the launch depth according to the battlefield environment and the enemy situation, without having to surface or dive to the predetermined launch depth, which effectively shortens the preparation time before launch; on the other hand, each time a submarine launches a missile, it will increase the risk of being discovered and attacked. When using variable depth launch, submarines can launch missiles at different launch depths, which improves the submarine's concealment and survivability. Therefore, some countries with submarine-launched technology attach great importance to the research of variable depth launch technology.

[0003] The power system composed of multiple gas generators is an effective way to solve the problem of underwater variable depth launch of payloads. At present, variable depth launch is mostly achieved by igniting different numbers of gas generators at different time sequences. However, the power system of multiple gas generators ignited at different time sequences will cause multiple pressure peaks to appear in the launch tube, resulting in an oscillating pressure curve, and then forming an oscillating load acceleration curve, which is not suitable for the launch of payloads with strict requirements on acceleration changes. In addition, the system has high requirements on the clock accuracy of the ignition control circuit, which increases the complexity of the ignition control system, reduces its robustness, and thus reduces its scope of application. In order to solve the above problems, it is necessary to invent a solution for the synchronous ignition of multiple gas generators that can adapt to variable depth launch and a corresponding internal ballistic design method. Summary of the invention

[0004] In order to solve the problems of narrow variable depth range, large deviation of exit speed and drastic acceleration change in the power working process of the existing multi-gas generator combination based on sequential ignition, the purpose of the present invention is to provide an optimization method for multi-gas generators with variable depth launch, according to the load launch constraint conditions and index requirements, the parameters such as loading conditions, nozzle throat diameter and number of gas generators are optimized, so that the load of specified mass, diameter and length can obtain the specified exit speed under the conditions of different launch depths, and the acceleration of the load in the launch tube does not exceed a certain allowable value; the number of working gas generators is flexibly adjusted according to the variable depth range, so as to realize wide range variable depth launch; the synchronous ignition of the gas generator can avoid the multiple pressure peaks generated by the sequential ignition, and the load speed of the overall ejection process increases steadily; the time matching design of the surface combustion charge can further reduce the pressure peak value and reduce the deviation range of the load exit speed.

[0005] The object of the present invention is achieved by the following technical solutions.

[0006] An optimization method for a multi-gas generator with variable-depth launch disclosed by the present invention, according to the load launch constraint conditions and index requirements, according to the shallowest launch depth H1 = H min Determine the initial values of the charge size parameters, the number of charge columns loaded, and the nozzle throat diameter of the No. 1 gas generator, substitute the initial values into the interior ballistic equations for solution, and then adjust the relevant parameters according to the calculation results, and iterate repeatedly to determine a set of charge size parameters, the number of charge columns loaded, and the nozzle throat diameter with a pressure ratio less than the critical pressure ratio and meeting all technical indicators, that is, realize the optimization of the multi-gas generator.

[0007] The interior ballistic equations mainly include the high-pressure chamber pressure equation, the gas flow equation, the energy conservation equation, the low-pressure chamber pressure equation, and the load motion equation;

[0008] Among them, the high-pressure chamber pressure calculation equation is

[0009]

[0010] In the formula: the subscript i (i = 1, 2,..., n) represents the number of the gas generator, p 1,i is the high-pressure chamber pressure, R is the gas constant of the gas, T1 is the high-pressure chamber gas temperature, V 1,i is the free volume of the high-pressure chamber, ρ p is the charge density, S b,i is the burning surface area of the charge, u i is the burning rate of the charge, is the gas flow rate at the nozzle throat of the high-pressure chamber;

[0011] The gas flow equation is

[0012]

[0013] In the formula: φ i is the flow correction coefficient of the nozzle, S t,i is the cross-sectional area of the nozzle throat, k is the specific heat ratio of the gas, p2 is the low-pressure chamber pressure, p cr is the critical pressure ratio;

[0014] The energy conservation equation is

[0015]

[0016] In the formula: T2 is the low-pressure chamber gas temperature, χ is the heat dissipation correction coefficient, S2 is the cross-sectional area of the launch tube, v m is the load motion speed;

[0017] The low-pressure chamber pressure equation is

[0018]

[0019] Where: m t is the total mass of the fuel gas flowing into the low-pressure chamber, V 20 is the initial free volume of the low-pressure chamber, l m is the stroke of the load movement;

[0020] The load movement equation is

[0021]

[0022] Where: M is the load mass, p b is the pressure at the depth where the load is located, μ is the dynamic friction coefficient between the load and the launch tube, C is the fluid resistance coefficient, ρ w is the density of water.

[0023] An optimization method for a multi-gas generator with variable-depth launch disclosed by the present invention includes the following steps:

[0024] S1. Given the load launch constraint conditions and index requirements, including but not limited to load mass, load size, launch depth range, out-of-tube velocity range, acceleration threshold;

[0025] S2. According to the working condition of the shallowest launch depth H1 (H1 = H min ), based on the load launch constraint conditions and index requirements, determine the initial values of the charge size parameters, the number of charge columns loaded, and the nozzle throat diameter of the No. 1 gas generator, then substitute them into the interior ballistic equations for solution, and then adjust the relevant parameters according to the calculation results, and iterate repeatedly until a set of charge size parameters, the number of charge columns loaded, and the nozzle throat diameter with a pressure ratio less than the critical pressure ratio and meeting all technical indicators are determined;

[0026] S3. Gradually increase the launch depth of the load until the No. 1 gas generator cannot meet the technical indicators when working alone. Record this launch depth as H2, and H2 is the depth at which the No. 2 gas generator starts to ignite and work;

[0027] S4. According to the working condition of the launch depth H2, use the number of charge columns loaded and the nozzle throat diameter of the No. 1 gas generator as the initial values of the number of charge columns loaded and the nozzle throat diameter of the No. 2 gas generator, then substitute them into the interior ballistic equations for solution, and then adjust the number of charge columns loaded and the nozzle throat diameter of the No. 2 gas generator according to the calculation results, and iterate repeatedly until the No. 1 and No. 2 gas generators can meet all technical indicators when working simultaneously;

[0028] S5. Iterate repeatedly according to steps S3 and S4. When performing the (N - 1)th (N = 2, 3,...) iteration, H N increases to the maximum launch depth H maxIf the first N-1 gas generators can meet all technical indicators when working at the same time, the internal ballistic optimization is completed. Otherwise, the relevant parameters of the Nth gas generator are optimized according to step S4 until the N gas generators can meet all technical indicators when working at the same time, and the charge size, charge column loading quantity, nozzle throat diameter and gas generator quantity are obtained, that is, the optimization of multiple gas generators is achieved.

[0029] Furthermore, in step S2, the type of charge used is inner hole surface increase combustion. In terms of size optimization, the charge working time is consistent with the load exiting the tube time when launching at maximum depth, and when launching at shallow depth, the charge working time is longer than the load ejection time, that is, the charge has not been completely burned, but the load has been ejected from the tube. Energy regulation is achieved through time matching to reduce the deviation range of the load exiting the tube speed.

[0030] Furthermore, in step S2, the internal ballistic equations mainly include the high-pressure chamber pressure equation, the gas flow equation, the energy conservation equation, the low-pressure chamber pressure equation and the load motion equation.

[0031] The multi-gas generator for variable depth launch comprises a launch tube, a load, a gas generator group, a gas generator, a nozzle, a circular plugging cover, a charge and an ignition charge.

[0032] The load is located inside the launch tube, and the gas generator group is installed side by side in the free space behind the load; the gas generator is filled with ignition powder and charge, the nozzle is installed on the gas generator, and a round plug is installed at the nozzle outlet.

[0033] The shape and size of each gas generator are the same, but the nozzle throat diameter and the amount of charge loaded are different; the number of gas generators, nozzle throat diameter and the amount of charge loaded are obtained through internal ballistic optimization based on the load launch depth range and technical indicators.

[0034] Beneficial effects:

[0035] 1. The present invention discloses an optimization method for a multi-gas generator for variable depth launch, according to the load launch constraint conditions and index requirements, according to the shallowest launch depth H1 = H min The initial values of the charge size parameters, grain loading quantity and nozzle throat diameter of No. 1 gas generator are determined, and the initial values are substituted into the internal ballistic equation group for solution. Then, the relevant parameters are adjusted according to the calculation results, and repeated iterations are performed to determine a set of charge size parameters, grain loading quantity and nozzle throat diameter with a pressure ratio less than the critical pressure ratio and meeting all technical indicators. This means that the optimization of the multi-gas generator is achieved, and the power operation of the multi-gas generator combination based on sequential ignition can be realized, overcoming the problems of narrow variable depth range, large deviation of barrel exit speed and drastic acceleration change during the operation of the multi-gas generator.

[0036] 2. An optimization method for a multi-gas generator with variable-depth launch. By means of interior ballistic design, the gas flow velocity at the throat of the gas generator nozzle reaches the local sonic speed, so that the pressure disturbance in the low-pressure chamber cannot be transmitted reversely into the nozzle interior, realizing that the working condition of the gas generator is not affected by the low-pressure chamber pressure and the launch depth, and providing guarantee for the smooth change of the low-pressure chamber pressure curve at different launch depths.

[0037] 3. An optimization method for a multi-gas generator with variable-depth launch. The grain size, grain shape, etc. in each gas generator are kept consistent, that is, the charge in each gas generator only differs in the filling quantity; adopting synchronous ignition design can effectively solve the problem of multiple pressure peaks in sequential ignition design, and adopting different charge designs can avoid the problem of too high a single pressure peak in the interior ballistic of a single gas generator, enhancing the practicability of the multi-gas generator power system in the field of variable-depth launch. Description of the Drawings

[0038] Figure 1 is the algorithm flowchart of the design method of the multi-gas generator with variable-depth launch.

[0039] Figure 2 is the structural schematic diagram of the multi-gas generator with variable-depth launch.

[0040] Wherein, 1 - launch tube, 2 - payload, 3 - gas generator group, 4 - gas generator, 5 - nozzle, 6 - circular plug, 7 - charge, 8 - ignition charge.

[0041] Figure 3 is the curve of the payload ejection speed and the maximum acceleration varying with the launch depth.

[0042] Figure 4 is the curve of the low-pressure chamber pressure varying with time at different launch depths.

[0043] Figure 5 is the curve of the payload acceleration varying with time at different launch depths.

[0044] Figure 6 is the curve of the payload velocity varying with time at different launch depths. Detailed Embodiments

[0045] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following further illustrates the detailed embodiments of the present invention in the application scenario of a submarine launching a torpedo underwater and in combination with the drawings.

[0046] As Figure 1As shown in the figure, an optimization method for a multi-gas generator with variable-depth launch disclosed in this embodiment first inputs known parameters such as payload mass, payload size, launch depth range, muzzle velocity range, and acceleration threshold, and then starts internal ballistic calculations from the shallowest launch depth H min and sequentially increases the number of gas generators and the launch depth until all gas generators can meet all design indicators when working synchronously under the maximum launch depth H max Finally, design results such as charge size, number of charge columns loaded, nozzle throat diameter, and number of gas generators are output. The specific steps are as follows:

[0047] 1. Given the launch constraint conditions and index requirements of the payload, the payload mass is 1582 kg, the payload diameter is 533 mm, the payload length is 5.85 m, the launch depth range is 15 - 125 m, the muzzle velocity range is 22 - 27 m / s, and the maximum acceleration does not exceed 12g;

[0048] 2. According to the working condition of the shallowest launch depth of 15 m, determine the initial values of the charge size parameters, number of charge columns loaded, and nozzle throat diameter of the No. 1 gas generator according to the launch constraint conditions and index requirements of the payload, and calculate the high-pressure chamber pressure. The calculation equation is

[0049]

[0050] where: the subscript i = 1 represents the number of the gas generator, p 1,i is the high-pressure chamber pressure, R is the gas constant of the gas, T1 is the gas temperature in the high-pressure chamber, V 1,i is the free volume of the high-pressure chamber, ρ p is the charge density, S b,i is the burning surface area of the charge, u i is the burning rate of the charge, is the gas flow rate at the nozzle throat of the high-pressure chamber;

[0051] The gas flow rate calculation formula in the high-pressure chamber pressure equation is

[0052]

[0053] where: is the flow correction coefficient of the nozzle, S t,i is the cross-sectional area of the nozzle throat, k is the specific heat ratio of the gas, p2 is the low-pressure chamber pressure, p cr is the critical pressure ratio;

[0054] Then, calculate the gas temperature in the low-pressure chamber. The calculation equation is

[0055]

[0056] Where: T2 is the gas temperature in the low-pressure chamber, χ is the heat dissipation correction coefficient, S2 is the cross-sectional area of the launch tube, and v m is the load movement speed;

[0057] Next, calculate the low-pressure chamber pressure. The calculation equation is

[0058]

[0059] Where: m t is the total mass of the gas flowing into the low-pressure chamber, V 20 is the initial free volume of the low-pressure chamber, l m is the load movement stroke; Finally, calculate the load movement law. The calculation equation is

[0060]

[0061] Where: M is the load mass, p b is the pressure at the depth where the load is located, μ is the dynamic friction coefficient between the load and the launch tube, C is the fluid resistance coefficient, and ρ w is the density of water.

[0062] If the calculated pressure ratio is less than the critical pressure ratio and all design indicators are met, the design of the No. 1 gas generator is completed; otherwise, adjust the initial values and iterate repeatedly;

[0063] 3. Gradually increase the launch depth of the load and conduct internal ballistics calculations until the No. 1 gas generator cannot meet the technical indicators when working alone. At this time, the launch depth is 42 m, that is, the No. 2 gas generator starts to ignite and work when the launch depth is equal to 42 m;

[0064] 4. According to the working conditions at the launch depth of 42 m, use the charge loading quantity and nozzle throat diameter of the No. 1 gas generator as the initial values of the charge loading quantity and nozzle throat diameter of the No. 2 gas generator, then substitute them into the internal ballistics equations for solution, and then adjust the charge loading quantity and nozzle throat diameter of the No. 2 gas generator according to the calculation results, and iterate repeatedly until all technical indicators can be met when the No. 1 and No. 2 gas generators work simultaneously;

[0065] 5. Iterate repeatedly according to steps 3 and 4. When performing the third iteration, H N increases to the maximum launch depth of 125 m. At this time, the simultaneous operation of the first three gas generators cannot meet all the technical indicators. Therefore, design the relevant parameters of the No. 4 gas generator according to step 4 until all technical indicators can be met when the four gas generators work simultaneously;

[0066] 6. Finally, design results such as the charge size, the number of propellant grains loaded, the nozzle throat diameter, and the number of gas generators are output. Among them, the inner diameter of the charge is 44 mm, the outer diameter is 95 mm, and the length is 70 mm. The number of propellant grains loaded in the 1st gas generator is 6, the nozzle throat diameter is 27 mm, and it starts to work when the launch depth is equal to 15 m; the number of propellant grains loaded in the 2nd gas generator is 3, the nozzle throat diameter is 18 mm, and it starts to work when the launch depth is equal to 42 m; the number of propellant grains loaded in the 3rd gas generator is 3, the nozzle throat diameter is 18 mm, and it starts to work when the launch depth is equal to 75 m; the number of propellant grains loaded in the 4th gas generator is 2, the nozzle throat diameter is 13 mm, and it starts to work when the launch depth is equal to 108 m.

[0067] As Figure 2 shown, a structure of a multi-gas generator for variable-depth launch includes a launch tube, a payload, and a gas generator group. The gas generator group consists of 4 gas generators. Each gas generator includes a nozzle, a circular plug, a charge, and an ignition charge. The payload is located inside the launch tube, and the 4 gas generators are installed side by side in the free space behind the payload. The gas generator is filled with an ignition charge and a charge, the nozzle is installed on the gas generator, and a circular plug is installed at the nozzle outlet.

[0068] An optimization method for a multi-gas generator for variable-depth launch disclosed in this embodiment controls a certain number of gas generators to ignite and work synchronously according to the launch depth of the payload, realizing variable-depth launch of the payload. The specific working method is as follows: when the payload is at a depth of 15 m to 42 m underwater, only the 1st gas generator ignites and works, and the out-tube speed of the payload is 23.26 m / s to 26.71 m / s; when the payload is at a depth of 42 m to 75 m underwater, the 1st and 2nd gas generators ignite and work synchronously, and the out-tube speed of the payload is 23.41 m / s to 26.85 m / s; when the payload is at a depth of 75 m to 108 m underwater, the 1st, 2nd, and 3rd gas generators ignite and work synchronously, and the out-tube speed of the payload is 23.37 m / s to 26.20 m / s; when the payload is at a depth of 108 m to 125 m underwater, the 1st, 2nd, 3rd, and 4th gas generators ignite and work synchronously, and the out-tube speed of the payload is 23.49 m / s to 24.78 m / s.

[0069] During the launch process of the payload, the maximum acceleration is between 8.72g and 11.57g. As Figure 4 shown, the consistency of the acceleration characteristic value during the out-tube process of the payload is ensured. From a launch depth of 15 m to 125 m, the out-tube speed is between 23.26 m / s and 26.85 m / s. As Figure 5 shown, the deviation of the out-tube speed does not exceed 2 m / s, all meeting the design indicators, that is, the optimization of the multi-gas generator is realized.

[0070] The above description has further elaborated on the purpose, technical solution and advantages of the present invention. It should be understood that the above is only a specific implementation process of the present invention for explaining the present invention, and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An optimization method for a multi-gas generator with variable-depth emission, characterized in that: The interior ballistic equations mainly include the high-pressure chamber pressure equation, the gas flow equation, the energy conservation equation, the low-pressure chamber pressure equation, and the load motion equation; Among them, the high-pressure chamber pressure equation is Where: the subscript i represents the number of the gas generator, i = 1, 2, …, n, p 1,i is the pressure in the high-pressure chamber, R is the gas constant of the fuel gas, T1 is the temperature of the fuel gas in the high-pressure chamber, V 1,i is the free volume of the high-pressure chamber, ρ p is the charge density, S b,i is the burning surface area of the charge, u i is the burning rate of the charge, is the fuel gas flow rate at the nozzle throat of the high-pressure chamber; The gas flow equation is Where: φ i is the flow correction coefficient of the nozzle, S t,i is the cross-sectional area of the nozzle throat, k is the specific heat ratio of the gas, p2 is the pressure in the low-pressure chamber, p cr is the critical pressure ratio; The energy conservation equation is Where: T2 is the gas temperature in the low-pressure chamber, χ is the heat dissipation correction coefficient, S2 is the cross-sectional area of the launcher tube, and v m is the moving speed of the payload; The low-pressure chamber pressure equation is Where: m t is the total mass of the fuel gas flowing into the low-pressure chamber, V 20 is the initial free volume of the low-pressure chamber, l m is the load movement stroke; The load motion equation is Where: M is the load mass, p b is the pressure at the water depth where the load is located, μ is the dynamic friction coefficient between the load and the launch tube, C is the fluid resistance coefficient, ρ w is the density of water; The optimization method includes the following steps: S1. Given the load launch constraint conditions and index requirements, including but not limited to load mass, load size, launch depth range, muzzle velocity range, acceleration threshold; S2. According to the operating condition with the shallowest launch depth H1, where H1 = H min , determine the initial values of the charge size parameters, the number of grain loadings, and the nozzle throat diameter of the No. 1 gas generator according to the load launch constraint conditions and index requirements. Then substitute them into the interior ballistics equations for solution, and adjust the relevant parameters according to the calculation results, and iterate repeatedly until a set of charge size parameters, the number of grain loadings, and the nozzle throat diameter with a pressure ratio less than the critical pressure ratio and meeting all technical indicators are determined; S3. Gradually increase the launch depth of the load until the technical indicators cannot be met when the No. 1 gas generator works alone. Denote this launch depth as H2, and H2 is the depth at which the No. 2 gas generator starts to ignite and work; S4. According to the working conditions of the launch depth H2, take the number of grain charges and the nozzle throat diameter of the No. 1 gas generator as the initial values of the number of grain charges and the nozzle throat diameter of the No. 2 gas generator, then substitute them into the interior ballistic equations for solution, and then adjust the number of grain charges and the nozzle throat diameter of the No. 2 gas generator according to the calculation results, and iterate repeatedly until all technical indicators can be met when the No. 1 and No. 2 gas generators work simultaneously; S5. Iterate repeatedly according to steps S3 and S4. When performing the (N - 1)-th iteration, N = 2, 3, …, H N Increase to the maximum launch depth H max , if the simultaneous operation of the first N - 1 gas generators can meet all the technical indicators, the interior ballistic optimization is completed; otherwise, optimize the relevant parameters of the N-th gas generator according to step S4 until the simultaneous operation of the N gas generators can meet all the technical indicators, and obtain the charge size, the number of grain loadings, the nozzle throat diameter, and the number of gas generators, that is, the optimization of multiple gas generators is achieved.

2. The optimization method of a multi-gas generator with variable-depth emission according to claim 1, characterized in that: In step S2, the charge type adopted is internal hole area-increasing combustion. In terms of size optimization, the charge working time is the same as the load muzzle time at the maximum depth launch. When launching at a shallow depth, the charge working time is longer than the load ejection time, that is, the charge has not burned out and the load has already left the barrel. Energy regulation is achieved through time matching to narrow the deviation range of the load muzzle velocity.

3. The optimization method of a multi-gas generator with variable-depth emission according to claim 1 or 2, characterized in that: The multi-gas generator for variable-depth launch includes a launch tube (1), a load (2), and a gas generator group (3); the gas generator group (3) is composed of gas generators (4); The load (2) is located inside the launch tube (1), and the gas generators (4) are arranged side by side in the free space behind the load; the gas generators (4) are equipped with igniters (8) and charges (7) inside, and nozzles (5) are installed on the gas generators (4), and circular plugs (6) are installed at the outlets of the nozzles (5); The shape and size of each gas generator (4) are the same, but the throat diameters of the nozzles (5) and the numbers of grain charges (7) are different; the number of gas generators (4), the throat diameters of the nozzles (5), and the numbers of grain charges (7) are obtained through interior ballistic optimization according to the load (2) launch depth range and technical indicators.

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