快/慢烤试验中复合推进剂内部温度场的分布

为了研究不同烤燃条件下复合推进剂(PBT/HMX/Al/AP/BU)的响应特性,采用DSC研究了复合推进剂及单组分的热分解特性。复合推进剂的初始分解温度为187.27℃,单组分中BU初始分解温度最低,为192.95℃,表明复合推进剂的热分解过程是从BU开始;分别测量了在快/慢烤试验中,复合推进剂内部温度的变化。结果表明:1)快烤试验中,样品内部温度分布极不均匀。点火90 s后,样品发生反应,此时样品中心的温度为85℃,钢管端盖破裂,样品发生燃烧反应。2)慢烤试验中,样品内部温度分布均匀,几乎无温度差,样品发生反应时,样品内部温度与环境温度均为133℃,试验后样品钢管完全破碎,样品发生了爆轰。由此可见,慢烤试验中,由于样品内部温度分布均匀,发生反应时,大部分样品都处于临界反应温度,一旦激发,破坏效应比快烤试验更严重。

Internal Temperature Field Distribution of the Composite Propellant during Fast/Slow Cook-off Test

In order to study the response characteristic of composite propellant (PBT/HMX/AL/AP/BU) under different cook-off conditions,DSC was used to measure the thermal decomposition characteristic of the composite propellant and each of its single components.The initial decomposition temperature of the propellant is 187.27 ℃,and that of BU is 192.95 ℃ which is the lowest among all components.Thus,the thermal decomposition process is started from BU.The internal temperature field distribution of the composite propellant subjected to fast/slow cook-off test was also studied.Results indicate that the temperature distribution of the propellant is non-uniform in the fast cook-off test.90 s after the ignition,the central temperature of the sample is only 85 ℃,the pipe cap is ruptured and the combustion reaction occurs.Whilst the temperature distribution of the propellant is uniform in the slow cook-off test,the internal and the environmental temperatures are both 133 ℃.The pipe was completely broken,and a detonation reaction happened.Thus,in the slow cook-off test,since the internal temperature distribution is uniform,and most of the samples are in the critical reaction temperature,once an excitation occurs,the destructive effect will be more serious than that in the fast cook-off test.