Numerical Simulation of Shock-Induced-Combustion in Three-Dimensional HyShot Scramjet Model

This paper presents a computational fluid dynamics (CFD) study of non-reacting and reacting flows within a scramjet model, and for the latter the flow domain is fueled with hydrogen and operated at shock tunnel flow conditions. This scramjet model includes two inlet compression ramps, a combustion chamber and thrust surfaces. The hydrogen is injected through the ramp surfaces, and the ignition is trigged by increased gas mixture temperature due to strong shock-waves. The primary goal of the study is to evaluate the detailed shock-induced-combustion processes and compare those CFD-predicted wall pressure distributions with available experimental data, thus to understand underlying combusting flow physics. For the “fuel off” cases, the CFD simulation produces quite a good wall pressures compared with the measurements. While for the ‘fuel on’ cases, despite short penetration depth of fuel injection from the simulation, the desired radical farming process has been partially achieved in the flow field adjacent to the combustor walls. The radical farming provides a mechanism by which combustion can be achieved with mild intake compressions, which leads to greater intake efficiency (with less total pressure loss) and overall greater scramjet performance. One major difference between experiment and calculation is that the significant combustion heat release observed in the experiment was not reproduced in the calculation at the same position. Future work will continue to focus on heat release of simulation works and predictions with different types of fuels.