Numerical Investigations At High Altitudes For Nozzles Performance Monitoring

Large area ratio nozzles that are employed for space propulsion applications not meant to be tested at the ground-level conditions because of flow occurs in their divergent section due low exhaust pressures. Therefore, it is desired perform experimental evaluation high-altitude evaluate performance said nozzles. Generally, a test facility, consisting supersonic diffuser, generally employed. In thispaper, second-throat diffuser has been numerically investigated predict its minimum starting pressure, and understand physics using Computational Fluid Dynamics (CFD). Numerical computation field system done two cases: 1) when nozzle initially evacuated 2) ambient pressure (1 bar). Simulations have carried out cold situation (Ȗ=1.4) over range inlet stagnation results compare favorably with theoretical provide adequate insight internal shock structures formed thediffuser addition wall vacuum thrust.