Simulation of overexpanded low-density nozzle plume flow

Abstract

The direct simulation Monte Carlo method was applied to the analysis of low-density nitrogen plumes exhausting from a small converging-diverging nozzle into finite ambient pressures. Two cases were considered that simulated actual test conditions in a vacuum facility. The numerical simulations readily captured the complicated flow structure of the overexpanded plumes adjusting to the finite ambient pressures, including Mach disks and barrel-shaped shocks. The numerical simulations compared well to experimental data of Rothe.