隔板厚度对延期时间影响的数值模拟及实验研究

The Numerical Simulation and Experiment Research of the Thickness of Bulkhead Impacting on Delay time

运用STAR-CD仿真软件,建立了以硅系延期药为输入药剂的金属隔板式延期装置的理论模型。数值模拟了隔板厚度分别为1 mm、2 mm和3 mm时燃烧波、壳体的传热、点火药升温过程等。理论设定点火药端面达到某温度所需时间与该爆发点温度下延滞期之和的最小值为延期装置的延期时间,研究了隔板厚度对延期时间的影响。结果表明:延期药燃烧完一段时间后,借助隔板的热传导,点火药温度逐渐升高,直至发火,点火药的中心温度高于边缘的温度。对延期时间-温度曲线进行拟合,其符合6次多项式。隔板厚度为2 mm和3 mm时数值计算的延期时间为3.55 s和4.44 s,实际测试值为2.97 s和4.03 s.同传统延期装置相比,金属隔板式延期装置能有效地延长延期时间。

A theoretical model of the metal-bulkhead delay equipment with the silicon type delay composition is established by the STAR-CD software. The numerical simulation is made to investigate the combustion wave,the heat transfer of shell and the temperature rise process of ignition composition with the bulkhead thicknesses of 1 mm,2 mm and 3 mm. It is assumed that the minimum value of sum of the time when the temperature of ignition charge rises to a certain temperature and the ignition delay time is the delay time of the device. The temperature distribution profile shows that the temperature of the ignition composition gradually increases by the thermal conductivity of bulkhead and is finally fired after the burning-out of delay composition,and the center temperature of the ignition composition is higher than that of its edge. The delay time-temperature curve can be fitted as a 6th order polynomial. When the thickness of a bulkhead is 2 mm or 3 mm,the simulation value of the delay time is 3. 55 s or 4. 44 s,and the experimental value is 2. 97 s or 4. 03 s. Compared with the traditional pyrotechnic delay device,the heat transfer delay device can effectively extend the delay time.