CFD Modeling of the Hypersonic Inlet Starting Problem

Abstract

*† ‡ The viability of using two different Computational Fluid Dynam ics (CFD) codes to model complex hypersonic flow and inlet starting phenomena is examined, with simpler geometries used to gauge the accuracy of the codes’ predictions. The two RANS codes used were Choi’s UTNS and NASA’s CFL3D. First explored was a conve rgent -divergent nozzle geometry, simulating steady flow both with and without the effects of viscosity. The downstream static pressure was then varied using a time varying boundary condition to determine the transient accuracy of the codes. The final sim ulation was for the flow in the hypersonic inlet geometry. Using the Kantrowitz limit for inlet starting as a guideline, various free stream Mach numbers were simulated to determine whether the codes would predict consistent starting results. This inlet geometry was also run transiently to further explore the mechanics behind the starting and operating limits of the hypersonic inlet.