SIMULATION OF OVEREXPANDED LOW-DENSITY NOZZLE PLUME FLOW

The direct simulation Monte Carlo method was applied to the analysis o f low-density nitrogen plumes exhausting from a small converging-diver ging nozzle into finite ambient pressures. Two cases were considered t hat simulated actual test conditions in a vacuum facility. The numeric al simulations readily captured the complicated flow structure of the overexpanded plumes adjusting to the finite ambient pressures, includi ng Mach disks and barrel-shaped shocks. The numerical simulations comp ared well to experimental data of Rothe.