论文部分内容阅读
流注茎的热特性是研究先导形成与发展的关键问题,建立适用于流注茎温度场测量的系统对深入研究先导放电机理具有重要的意义.该文通过合理地设计光路、选择光源与透镜的参数,建立了一套空间分辨率为70μm、时间分辨率为5μs、灵敏度较高,适用于测量流注茎温度的定量纹影系统,同时根据纹影图片的特点以及流注茎的特性,提出了纹影图片的处理方法和流程,实现了对流注茎温度场的测量.通过开展长空气间隙先导放电试验,获得了流注茎的注入电流和纹影图片,基于提出的流注茎温度场的计算流程,获得了流注茎的径向温度分布,结果表明,流注茎的温度在25μs内从300K上升至720K,而且前期的上升速率要高于后期.“,”The thermal characteristics of stem is a key problem to understand formation and development of the leader discharge.Thus,it is meaningful to develop a system which can measure the temperature of stem.Designing the optical path and selecting the light source and lens rationally,a quantitative schlieren system was established in this paper.It has the spatial resolution of 70μm and time resolution of 5μs,and high sensitivity,which is applicable the measurement of the stem temperature field.Based on the characteristics of the schlieren photographs and stem,an image processing method and procedure was developed.Then experiments of long air discharge were carried out.The temperature of stem was calculated using the quantitative schlieren system.The results show that the temperature of the stem increases from 300K to 720K during 25μs,and the rate of temperature rising is larger at first than later.