Numerical Analysis of a Model Scramjet Engine with Two Intake Side Walls and a Cavity Flame-Holder

摘要

A detailed 3D numerical simulation of the flow and H_2-air mixing characteristics in a model scramjet engine with two intake-sidewalls and a cavity flame-holder was conducted. Turbulence closure was achieved by a model combining the low-Reynolds-number k-e two-equation model and Sarkar and Wilcox's compressible turbulent correction model. The governing equations were solved numerically by means of a finite-volume, preconditioned flux-differencing scheme. Cases with and without intake side walls were considered. Intake side walls were found to strongly affect the inlet flow structure, which became more complex in the non-uniform flow field on the cross section perpendicular to the engine axis. The complex and non-uniform flow affected the H_2-air mixing pattern inside the combustion chamber, unlike the pattern of the case without side walls. Mixing efficiency and fuel propagation rate were evaluated for the two cases with and without side walls. To verify the accuracy of the simulation, the computed wall pressure was compared with experimental data.