无热子空心阴极点火过程的放电维持失衡机理研究

The discharge maintenance imbalance of the heaterless hollow cathode （HHC） exerts a significant block on the HHC engineering application. In order to solve this problem above， a dynamical numerical model based on the plasma discharge coupling with the heat transfer has been established in this paper. Based on the electronic-path mesh generation， the time step of the discharge model can be set as same as that of the heat transfer model， which will increase both the computational efficiency and the accuracy. A test of the temperature measurement and anode current diagnosis was employed to justify and rectify the numerical model. The calculation relative error of the corrected model was as follows： the emitter temperature 2.5%~8.4%， and the anode current 5.6%~12.9%. Based on those above， the dynamical numerical simulation of the ignition process of the HHC at different operation cases was conducted. It is found that the existence of the electron emission decline zone will cause an imbalance of the HHC discharge maintenance. Furthermore， the probability of existence of the electron emission decline zone increases with the gas flow rate reducing， the keeper-tube gap distance reducing and the heat transfer capability of the cathode tube material increasing.