水射流出口压力对HTPB推进剂冲击安全性的影响

基于临界起爆判据Pnτ=K,通过对高压水射流出口压力的合理选择,研究HTPB推进剂发生冲蚀破碎过程中的安全性。依据水射流的冲击理论和推进剂的力学特性,得出最低出口压力,并讨论其对推进剂冲击安全性的影响。建立以水锤压力为危险源的飞片冲击模型,以临界起爆压力衡量水锤压力在SDT过程中的安全性。结果表明,在任何出口压力下,水锤压力对于SDT过程中的安全性无影响;而当出口压力达到100MPa时,在滞止压力作用下的温升变化异常,推进剂内部温度已接近临界温度,具有较大的危险性。通过评判两个阶段对HTPB推进剂的冲击安全性,确定出口压力的安全区间为60～100MPa。

Influence of Water Jet Outlet Pressure on Impacting Security of HTPB Propellants

Based on the criterion of critical ignition Pnτ=K,a reasonable choice for the outlet pressure of high pressure water jet was made to ensure the process security when HTPB propellant was broken by the erosion.According to the mechanical properties of HTPB propellant and the impacting theory of water jet,the lowest outlet pressure can be got.On this basis,the effect on impacting security was discussed for propellant.Through the establishment of the flyer shock model with hammer pressure as dangerous source,the critical initiation pressure can measure the safety determined by the hammer pressure in the SDT process.The results showed that the hammer pressure had no effect on security in the SDT process regardless of any outlet pressure;whereas the outlet pressure came to 100 MPa,the temperature rise began to be abnormal under the changing stagnation pressure because internal temperature of the propellants was close to the critical temperature,which had a greater risk.By judgment of the impacting security of the two phases,the outlet pressure was determined as the safe range of 60-100 MPa for HTPB propellant.