膛内等离子体点火及燃烧增强过程数值模拟

A Study on Numerical Simulation of Ignition and Combustion Enhancement with Plasma in Bore of ETC Guns

在初始点火过程中 ,假设等离子体为充分发展射流流动 ,因而可采用积分近似模型进行描述。而在随后的膛内燃烧过程中通过以经验公式给出等离子体混合长度的方法来处理等离子体的运动 ,并给出了合适的相间阻力及传热公式。通过在计算网格设计中引入了自适应方法提高了数值解精度。计算膛压曲线与实验符合良好。相对常规内弹道情形 ,等离子体能量的注入使在不同时刻膛内的气、固两相速度、压力和膛底温度等出现提高 ,这是等离子体注入后对内弹道的增强过程。计算结果为固体工质电热化学炮的弹道设计提供了理论依据。

Based on the assumption that the plasma in bore is a fully developed jet flow, the jet integeral approximation model for plasma ignition process is proposed. In the following combustion process, plasma flow is treated by introducing plasma mixing length in the form of empirical relations. Appropriate interphase drag and heat transfer formulation are also suggested. An adapted grid method has been incorporated to the above model to improve numerical calculation accuracy. Calculated pressure curves reproduce the experimental results well. Compare with the conventional interior ballistic situation, the velocity and pressure of gas, Solid phase at different time and temperature at bore bottom are increased. It shows the enhancement of interior ballistics by plasma injection. Calculated results provide a theoretical basis for the ballistic design of solid propellant electrothermal chemical(ETC) gun.