Extensive Validation of a Monte Carlo Model for Hydrogen Arcjet Flowfields

A particle-based Monte Carlo numerical method is applied for the e rst time to model the nozzle and plume e ows of a low-thrust hydrogen arcjet. Starting from a continuum solution of the e ow just downstream of the constrictor, the present analysis employs the direct simulation Monte Carlo technique to compute the nonequilibrium e uid mechanics and thermochemical relaxation. Simulation of plasma e eld effects is included at a simple level using charge neutrality. A model is implemented to include ohmic heating in the simulation. Results are presented for two different arcjet e ow conditions. Comparisons of Monte Carlo results with experimental measurements for a variety of e owe eld properties are made in the nozzle interior, the nozzle exit plane, and the near-e eld plume e ow. Comparison of prediction with measurement is also made for thruster performance. For almost all e ow properties, good agreement is obtained between simulation and measurement. This indicates that the Monte Carlo model is a viable approach for optimization of arcjet performance, and for the prediction of spacecraft interaction effects.