烟火药在定容条件下的爆燃p-t曲线仿真

通用的非线性显式动力学软件没有适用于模拟火工作动装置内烟火药作用过程的数学模型,导致动力学仿真只能采用多软件联合仿真。为简化仿真流程,采用MSC.Dytran软件新增的爆燃状态方程模拟烟火药在定容条件下的压力-时间历程(p-t曲线)。为验证仿真方法的适用性和准确性,进行了燃速较慢的炭黑/硝酸钾和燃速较快的铝/高氯酸钾两种烟火药的仿真和试验。对比分析了仿真结果与密闭爆发器试验结果在压力上升到半峰值(0.5pm)和到达压力全峰值(pm)两个时刻的时间差以及pm的相对误差。结果表明,炭黑/硝酸钾压力上升到0.5pm时,仿真结果和试验结果的时间差为0.03 ms,到达pm时的时间差为0.3 ms,pm的相对误差为7.4%～10%;与此相对应,铝/高氯酸钾在这两个压力点处的时间差分别为0.02 ms和0.1 ms,pm的相对误差在4%～6.3%。说明使用MSC.Dytran中的爆燃状态方程进行烟火药的p-t曲线仿真具有较好的准确性和适用性。

Simulation on p-t Curves of Deflagration of Pyrotechnical Compositions Under Constant Volume

Since the general nonlinear explicit dynamics software does not have a mathematical model suitable for simulating the action process of pyrotechnic actuated devices, the dynamics simulation can only be performed by multi-software co-simulation. In order to simplify the simulation process, the pressure-time history (p-t curves) of the pyrotechnic composition under constant volume conditions was simulated using the newly embedded deflagration equation of state of MSC.Dytran software. Simulation of slow-burning carbon black/potassium nitrate and fast-burning aluminum/potassium perchlorate were carried out and compared with experimental results to verify the applicability and accuracy of the simulation method. The time differences when the pressure rises to half of the peak pressure (0.5p_m) and reaches the peak pressure (p_m), and the relative errors of p_m were compared and analyzed between the simulation results and the closed bomb test results . Results show that when the pressure of charcoal/potassium rises to 0.5p_m, the time difference between the simulation result and the test result is 0.03 ms, the time difference when reaching p_m is 0.3 ms, and the relative error of p_m is 10%. Correspondingly, the time difference of aluminum/potassium perchlorate at these two conditions is 0.02ms and 0.1ms, and the relative error of p_m is 4%. The p-t curves simulation of pyrotechnic compositions using the deflagration equation of state in MSC.Dytran software has good accuracy and applicability.