一维热爆炸试验传热的数值模拟

Numerical Simulation of Heat Transfer on One-dimensional Time-to-Explosion Test

针对加热过程所涉及的主要传热学问题,分别建立空气夹层复合传热模型和炸药受热分解放热数值模型;计算分析了473K下油浴和空气浴加热时系统辐射率、空气对流换热系数对RDX、HMX、TATB 3种炸药热点火延滞时间的影响。结果表明,473K油浴加热和空气浴加热时RDX分别在151.7s和3 372.6s时发生热点火,表明相同温度和炸药,油浴加热时热点火延滞时间远小于空气浴加热;空气浴加热时,同一种炸药在相同温度下,随系统辐射率的降低,热点火延滞时间增加;RDX、HMX和TATB炸药辐射率由0.9降至0.1时,热点火延滞时间分别增加了180.1%、168.9%和169.3%;相同温度、相同系统辐射率条件下,对流换热系数减小,热点火延滞时间增加。

Aiming at the main heat trasfer problems involved in the heating process,the complex heat transfer model of air layer and the thermal decomposition heat release numerical model of explosive were established,respectively.The effects of system emissivity and convective heat transfer coefficient of air on the thermal ignition delay time of RDX,HMX,HTPB explosive samples when heating by oil bath and air bath at 473 K were calculated and analyzed.The results show that the ignition time of RDX by oil bath and air bath under the temperature of 473 Kare 151.7 s and 3 372.6 s,respectively,showing that under the same temperature and explosive,the thermal ignition delay time under oil bath heating was far less than that under air bath heating.As air bath heating,the ignition delay time increases with the decrease of the emissivity under the same temperature and explosive.The ignition delay time of RDX,HMX and TATB increase by 180.1%,168.9% and 169.3%respectively when the emissivity decreases from0.9 to 0.1.The thermal ignition delay time increases with the decreases of the convective heat transfer coefficient under the same temperature and the same emissivity.