A three-dimensional numerical study on the effect of geometric asymmetry on arcjet thruster performance  

作　　者：Hari Prasad NANDYALA Amit KUMAR Jayachandran THANKAPPAN 

机构地区：[1]Department of Aerospace Engg,Indian Institute of Technology Madras

出　　处：《Plasma Science and Technology》2023年第5期131-146,共16页等离子体科学和技术（英文版）

基　　金：the Indian Space Research Organization(VSSC-ISRO)for funding this research through ISRO-IITM Cell。

摘　　要：In an arcjet thruster,the cathode and constrictor degrade with time,and the electrical arc discharge may become unsymmetrical.In this work,a three-dimensional numerical model of a hydrogen plasma arcjet is developed and validated to study the effect of unsymmetrical electric arc discharge on thruster performance.The unsymmetrical arc discharge is realized by introducing a radial shift of the cathode so that the cathode tip offset is 80μm(25%of the constrictor radius).Simulations are conducted for both axially centered cathode(coaxial)and off-centered cathode(non-coaxial)configurations with identical propellant flow rates and input current.Simulations show asymmetrical arc discharge in the non-coaxial cathode configuration,resulting in azimuthally asymmetric Joule heating,species concentrations,and velocity field.This asymmetry continues as the plasma expands in the divergent section of the nozzle.Temperature,species concentrations,and axial velocity exhibit asymmetric radial distribution at the nozzle exit.The computed Joule heating was found to reduce with cathode shift,and consequently,the thrust and specific impulse of the thruster was decreased by about 6.6%.In the case of the non-coaxial cathode,geometric asymmetry also induces a small side thrust.

关 键 词：ARCJET geometric asymmetry 3D numerical modelling space electric propulsion HYDROGEN 

分 类 号：V439.4[航空宇航科学与技术—航空宇航推进理论与工程]