30mm电热化学炮膛内压力波数值模拟研究

使用包含瞬态燃速公式的一维内弹道模型模拟30 mm电热化学发射过程,通过与发射实验结果相比较,验证了该模型的精确性。对比常规发射和电热化学发射膛内压力波曲线可知,电热化学发射技术可以有效降低膛内压力波。进一步分析输入电能、放电时序、发射药弧厚、装填密度等参数变化对膛内压力波的影响。研究表明:同步放电的条件下,电能比不大于0.042时,压力波峰值变化很小;电能比大于0.042时,压力波峰值随着电能比的增加迅速增大;首个负波幅值随着电能比线性递增,但受电能比影响小于压力波峰值;采用时序放电时,在控制压力波的前提下,电能比与放电电流的脉宽呈正比;在较高电能比下,压力波峰值与放电电流的脉宽呈反比;随着发射药装填密度的增加,膛内压力波增大;但在控制压力波的前提下,可输入的电能比无明显变化,首个负波幅值随着电能比的变化趋势不变;弧厚的变化对压力波的影响可忽略不计。

Numerical Simulation on Pressure Wave in a 30 mm Electrothermal-chemical Gun

A one-dimensional internal ballistic model including the transient burning rate law is used to simulate the 30 mm electrothermal-chemical (ETC) launch. The accuracy of the model is proved by experimental data. Compared with classical ignition, the pressure wave decreases obviously while propellant is ignited by plasma. The effects of the initial parameters, such as input electric power, discharging timing sequence, propellant web thickness and loading density, on in-bore pressure wave are analyzed. In the condition of synchronous discharging, the peak value of pressure wave can be controlled while the electric energy ratio is less than 0.042. If the electric energy ratio is larger than 0.042, the peak value of pressure wave increases rapidly with the electric energy ratio. The first negative wave value is proportional to the electric energy ratio. Compared with the peak value of pressure wave, the first negative wave value is less affected by the electric energy ratio. In the condition of timing discharging, the allowed input electric energy ratio to control the pressure wave is proportional to the current pulse duration. At the high electric energy ratio, the peak value of pressure wave is inverse proportional to the current pulse duration. The pressure wave increases with the increase in loading density. But the allowed electric energy ratio to control the pressure wave showed no significant change, and the variation trend of the first negative wave value is unchanged. The influence of propellant web thickness on pressure wave in ETC launch can be ignored.