复合固体推进剂湿扩散数值模拟研究

Numerical Simulation of Moisture Diffusion of Composite Solid Propellant

为考察湿度作用下复合固体推进剂内部水分扩散及分布情况,揭示推进剂湿度老化机理,进行了推进剂吸湿试验,提出了推进剂内部水分扩散模型及有限元模型,对推进剂内部水分扩散进行了有限元数值模拟,分析了影响推进剂内部水分扩散的因素。结果表明,采用湿度有限元方法能够模拟推进剂的吸湿过程;温度对水分扩散有一定的影响,温度越高,扩散系数越大,水分在推进剂中扩散越快;推进剂试件尺寸对水分扩散也有一定的影响,试件尺寸越大,内部水分扩散速度越小,到达平衡的时间越长。

In order to elucidate the humidity aging mechanism of composite solid propellant, the diffusion and the distribution of moisture inside the composite solid propellant under humidity was evaluated through the hygroscopic test of propellant. The mathematical and the FE model of moisture diffusion were proposed. The FEM was employed to simulate the moisture diffusion inside propellant. Moreover, the factors that affect the moisture diffusion were analyzed. The results showed that the humidity FEM can be used to simulate the hygroscopic process inside propellant. The temperature can affect the moisture diffusion. The higher the temperature is, the greater the coefficient and the diffusion speed of moisture are Furthermore, the dimension of propellant specimen can also affect the moisture diffusion. That is, the diffusion speed of moisture becomes smaller with increasing the dimension of propellant specimen, and then the time to reach equilibrium becomes longer.