大气压下流注放电光电离过程的数值仿真

将光电离模型引入气体流注放电的流体模型中，针对光电离数值仿真计算需要对空间任意两点建立联系，导致方程求解计算量增大、计算较困难的问题，提出了光电离模型的简化计算方法。然后求解流注放电流体模型，仿真棒–板空气间隙放电过程，并比较了有和没有光电离2种情况，结果表明光电离提供了流注放电所必须的二次电子崩的种子电子，在没有光电离时，不能形成流注放电。在考虑光电离情况下仿真了流注发展过程，得到各时刻电子、光电子、电场空间分布，并从流注发展速度、通道半径、电场强度多方面与实验结果比较，验证了模型和算法的正确性。

Study on Photoionization Produced by Discharge in Atmospheric Air by Numerical Method

The photoionization model developed by Zhelezniak is introduced into the numerical simulation of streamer discharge in atmospheric air. Due to the non-locality of radiative transfer, the photoionization model involves describing radiative relations between all points of the plasma. To overcome the enormous effort required for calculation of photoionization in gas discharge problems, some simplified methods are implemented in this paper. The results of streamer discharge in rod-plane air gap with and without the process of photoionization are compared by numerical method. It shows that the photoionization offers the seed electron of secondary avalanche which is indispensable for streamer, so the streamer can’t develop without photoionization. The results of two-dimensional modeling of positive streamer dynamics in rod-plane gap are presented. The electric field distribution, streamer speed, radius of streamer channel predicted by the simulation is in good agreement with experimental measurement.