3d Computation of Single-expansion-ramp and Scramjet Nozzles

Description of the computations for three-dimensional nonaxisymmetric nozzles and analysis of the flowfields are presented in this paper. Two different types of nozzles are investigated for con~pressible flows at high Reynolds numbers. These are the single-expansionramp and scramjet nozzles. The computation for the single-expansion-ramp nozzle focuses on the condition of low pressure ratio, which requires the simulation for turbulent flow that is not needed at high pressure ratios. The flowfield contains the external quiescent air, and the internal regions of subsonic and low supersonic flows. The second type is the scramjet nozzle, which typically has a very large area ratio and is designed to operate at high speeds and pressure ratios. The freestream external flow has a Mach number of 6, and the internal flow leaving the combustion chamber is at a Mach number of 1.62. The flowfield is mostly supersonic except in the viscous region near walls. The computed results from both cases are compared with experimental data for the surface pressure distributions.