Computational Investigation of the Near-Field Plasma Plume in Ion-Ion Propulsion

Sankaran, K ; Widmer, T ; Dale, T ; Polzin, K A

关键词: PLUMES;    PLASMA PROPULSION;    ION PROPULSION;    ION ENGINES;    ELECTRIC POTENTIAL;    POSITIVE IONS;    NEGATIVE IONS;    PLASMA DECAY;    COMPUTERIZED SIMULATION;    TIME DEPENDENCE;    PARTICLE IN CELL TECHNIQUE;    TWO FLUID MODELS;    TRANSPORT THEORY;   

RP-ID  :  M18-6816

学科分类：航空航天科学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

A two-fluid numerical model of plasma flows was developed to investigate the plume of an ion-ion propulsion system. The densities of positive and negative ions, and the associated values of net charge, electric field, and electric potential were calculated as a function of time throughout the domain. The computational domain was chosen to be large enough (25 thruster diameters downstream of the exit plane) to allow for examining the neutralization of the plume. The resulting plasma electric potential and charge neutrality at the downstream end of the domain are shown and they indicate that it is possible to alternatively accelerate oppositely charged ions without the need for an electron-emitting neutralizer and without facing any electric potential hills that could cause stagnation. However, compared to existing literature on ion-ion plasma thrusters, the results from this simulation predict a longer length-scale for voltage decay.