电控固体推进剂的燃烧波结构和焦耳热增强燃烧模型

Combustion wave structure and Joule heat enhanced combustion model of electrically controlled solid propellant

为了明确电控固体推进剂(ECSP)燃烧性能的影响因素,揭示其燃速可调机理,利用燃烧波测试装置对硝酸羟胺(HAN)基ECSP的火焰结构进行了研究并且划分了燃烧波结构,基于燃烧波结构建立了推进剂的燃烧模型,计算了推进剂燃烧波内各区域的温度分布,根据燃面上的热平衡方程推导出了受加载电压、初始温度和环境压强等共同影响的推进剂燃速表达式,同时对该燃烧模型进行了验证与分析。结果表明:电压作用下,HAN基ECSP的燃烧波结构可以划分为预热区、电化学-热化学反应区、暗区、预混反应区和燃烧产物区五个部分,其中预热区、电化学-热化学反应区内的理论温度在变化趋势上和实测温度保持较好的一致性,随着加载电压增加上述两区域的厚度变薄。不同初始温度和环境压强下,燃速测试结果与理论计算结果的平均误差分别为10.9%和9.4%。加入导电石墨和铝粉可以分别从增加推进剂的电导率和能量释放两方面提高燃速,与ECSP燃烧模型预示的燃速变化趋势一致。本文建立了推进剂的焦耳热增强燃烧模型,验证了燃烧模型的准确性。

In order to clarify the factors that affect the combustion performance of hydroxylamine nitrate(HAN)-based electrically controlled solid propellant(ECSP)and reveal the mechanism of adjustable burning rate,the flame structure of HAN-based ECSP was studied using a combustion wave testing device,and the com⁃bustion wave structure was divided.Based on the combustion wave structure,the propellant combustion model was established.The temperature distribution in each area within the combustion wave was further calculated.Ac⁃cording to the heat balance equation on the burning surface,the expression of the burning rate that is jointly af⁃fected by the loading voltage,initial temperature and atmospheric pressure was derived.At the same time,the combustion model was verified and analyzed.The results show that under the action of voltage,the combustion wave structure of HAN-based ECSP can be divided into five parts:the preheating zone,the electrochemicalthermochemical reaction zone,the dark zone,the premixed reaction zone and the combustion product zone.The theoretical temperature in the preheating zone and electrochemical-thermochemical reaction zone maintains good consistency with the measured temperature in changing trends.As the voltage increases,the thickness of the above two regions becomes thinner.Under different initial temperatures and atmospheric pressures,the average errors between the test results and theoretical calculation results of the burning rate are 10.9%and 9.4%,respec⁃tively.Adding conductive graphite and aluminum can enhance the burning rate in terms of increasing conductivity and energy release respectively,which is consistent with the trend of burning rate changes predicted by the com⁃bustion model.The Joule heat enhanced combustion model of propellant was established and the accuracy of the combustion model was verified.