Computational and experimental investigations of rarefied flows in small nozzles

Detailed numerical and experimental studies are presented for unheated flows of hydrogen and nitrogen through a small nozzle, The nozzle geometry and flow conditions considered provide rarefied flows that are representative of resistojet thrusters employed on spacecraft for control. Computational results are obtained with the direct simulation Monte Carlo method, Experimental data are obtained using two different techniques, Measurements of axial velocity and translational temperature of hydrogen are performed using coherent anti-Stokes Raman scattering, Data are taken along the nozzle axis and in the exit plane of the nozzle, Measurements of thrust are obtained using a thrust stand for pure hydrogen, pure nitrogen, and for mixtures of the two, In all cases, the numerical predictions and experimental measurements are in excellent agreement.