基于动力学过程的固体推进剂降速机理

根据朗缪尔单分子吸附原理和AP分解的质子转移机理,分别在AP晶体界面和气相混合区中确立物质守恒关系,分析了AP在不同分解速率下气相混合区中NH_3和HClO_4的气相分子浓度关系;将其与AP晶体气固交界面的反应强度进行关联,建立了一种能够分析压强变化状态对推进剂燃速影响的动力学机理,并推导了相应的物理过程,通过实验将AP/降速剂(CaCO_3或NH_4C_2O_4)的TG-DSC分析结果与药条燃速结果进行了对比。结果表明,该降速机理能够解释降速剂对推进剂燃速和压强指数的多种作用,CaCO_3能够使AP的热失重分解温度出现一定程度的前移,因此对控制推进剂的高压压强指数有利,而NH_4C_2O_4不具备这种效果。

Dynamical Mechanism for Reducing Burning Rate of Solid Propellant

Based on the Langmuir adsorption theory and proton transfer mechanism of AP decomposition, the conservation of matter between solid and gas phases was utilized to determine the concentrations of NH3 and HClO4 in the gas phase for AP decomposing at different rates.Combining the gas concentrations with the reactions occurring on the solid-gas interfaces, a dynamic mechanism is proposed to elucidate the effects of changes in pressure on propellant burning rates,and physical processes had been deduced.According to experiments of AP/burning rate inhibitor (CaCO3 or NH4C2O4), results of both TG-DSC and burning rate test were compared.The results show that this mechanism can explain the processes that negative burning-rate catalysts act to effect the burning rates and pressure exponents.CaCO3 can decrease the thermal decomposition temperature of AP.So it is useful for controlling the pressure cxponents of propellants at high pressure.Nevertheless,NH4C2O4 do not have this effect.