期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
Plasma characteristics in the discharge region of a 20A emission current hollow cathode 被引量:1
1
作者 孙明明 张天平 +2 位作者 温晓东 郭伟龙 宋嘉尧 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第2期148-155,共8页
Numerical calculation and fluid simulation methods were used to obtain the plasma characteristics in the discharge region of the LIPS-300 ion thruster’s 20 A emission current hollow cathode and to verify the structur... Numerical calculation and fluid simulation methods were used to obtain the plasma characteristics in the discharge region of the LIPS-300 ion thruster’s 20 A emission current hollow cathode and to verify the structural design of the emitter.The results of the two methods indicated that the highest plasma density and electron temperature,which improved significantly in the orifice region,were located in the discharge region of the hollow cathode.The magnitude of plasma density was about 10^21m^-3in the emitter and orifice regions,as obtained by numerical calculations,but decreased exponentially in the plume region with the distance from the orifice exit.Meanwhile,compared to the emitter region,the electron temperature and current improved by about 36%in the orifice region.The hollow cathode performance test results were in good agreement with the numerical calculation results,which proved that that the structural design of the emitter and the orifice met the requirements of a 20 A emission current.The numerical calculation method can be used to estimate plasma characteristics in the preliminary design stage of hollow cathodes. 展开更多
关键词 ion thruster hollow cathode plasma characteristics
下载PDF
Numerical study of aerosol effect on three types of clouds and precipitation in Beijing area
2
作者 ZhiGuo Yue XiaoDong Liu ShuYan Liu 《Research in Cold and Arid Regions》 2012年第4期342-350,共9页
Three types of rainfall (storm, moderate and slight rainfall) in the Beijing area were simulated by the Weather Research and Fore- cast (WRF3.2) model coupled with Milbrandt-two-moment cloud microphysics scheme, t... Three types of rainfall (storm, moderate and slight rainfall) in the Beijing area were simulated by the Weather Research and Fore- cast (WRF3.2) model coupled with Milbrandt-two-moment cloud microphysics scheme, to explore the effect of aerosols on clouds and precipitation under continental and maritime aerosol scenarios. Results indicate that an increase of aerosols has various effects on clouds and precipitation. (1) The amount of surface precipitation is obviously affected. With an increase of aerosol con- centration, the 48-hr total precipitation of storm and moderate rainfall decreased by 23% and 16.6%, respectively, and the 24-hr total precipitation of slight rainfall decreased by 14.0%. (2) The distribution of surface precipitation is also clearly affected. The average precipitation for a rain storm increases in most parts of western Beijing and decreases by more than 20 mm in most parts of eastern Beijing with increasing aerosol concentration. The average precipitation of moderate rainfall decreases by 0.1-5 mm in most parts of the Beijing area. The effect of increased aerosol concentration is weak for slight rainfall distribution in the study area. (3) With an increase of aerosol concentration, a narrower width and lower precipitation peak value are found in the storm rainfall, and its duration is prolonged for the high aerosol concentration. An earlier precipitation termination of moderate rainfall is found with increasing aerosol concentration. (4) The upper-air hydrometeors vary with aerosol concentration, For storm and moderate rainfall, significantly higher cloud water concentration and lower rain water were found under the continental aerosol scenario. 展开更多
关键词 AEROSOL Beijing area clouds and precipitation indirect effect numerical simulation
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部