用于电热化学炮的放电毛细管烧蚀模型研究

摘要

To investigate the ablation quality parameters of the capillary to guide the design of ignition system,a theoretical research of the ablation process of polyethylene (PE) discharge capillary used for plasma ignition in electrothermal-chemical (ETC) launch was performed.The time distribution for ablation rate in a typical discharging cycle process was calculated by an ablation enthalpy method used in arc plasma magneto-hydrodynamics (MHD)simulation model.Radiant energy was calculated by a grey body radiation model and a net radiation coefficient model,and the effects on the ablation process were compared and analyzed.The results show that the plasma temperature on tube wall ablation rate has greater impact.Under the calculation condition of the same input parameter,there are many differences between the results obtained by two kinds of model.The theoretical calculation results obtained with grey body radiation model are close to experimental values.Net radiation coefficient method is suitable for big diameter discharge,whereas in the case of small diameter,the ablation results is underestimated.%为研究毛细管的烧蚀质量参数进而指导点火系统设计,对电热化学发射中等离子体点火用聚乙烯放电毛细管的烧蚀过程进行了理论研究.用电弧等离子体磁流体动力学仿真模型中的烧蚀焓方法,计算了一个典型放电周期过程中烧蚀率的时间分布.辐射能的计算分别采用灰体辐射模型与净辐射系数模型,对烧蚀过程的影响进行了对比分析.结果表明,等离子体的温度对管壁的烧蚀率有较大影响;在相同输入参数计算条件下,两种模型计算结果存在较大差异;灰体辐射模型理论计算结果与实验值接近.净辐射系数法适用于大管径放电情况,在小管径情况下则会低估烧蚀结果.