Mixing augmentation induced by the combination of the oblique shock wave and secondary recirculation jet in a supersonic crossflow

The mixing process of fuel-air in the supersonic crossflow is a pivotal technology for the scramjet engine. In this paper, numerical simulation of the transverse sonic hydrogen jet into a supersonic Mach 3 crossflow with the mixing augmentation strategy induced by the combination of the oblique shock wave and secondary recirculation jet has been carried out. Detailed flow field structures, hydrogen mass fraction distributions, vortex structures, heat flux and some parameters have been explored in order to investigate its mixing enhancement mechanism. Results of the three-dimensional Reynolds-average NavierStokes (RANS) equations coupled with the two-equation shear stress transport (SST) k-u turbulence model show that the combined strategy of the oblique shock wave and secondary recirculation jet device can effectively improve the mixing speed and mixing efficiency with little total pressure loss. Also, the secondary recirculation jet device can reduce the peak of the heat flux effectively. In this study, the case with the single bleed hole owns the best effect with improving the mixing efficiency by 82.75% locally and reducing the maximum heat flux by 15.24% respectively. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study numerically investigates the effect of the combined strategy of oblique shock wave and secondary recirculation jet on fuel-air mixing in supersonic crossflow. The results show that this strategy can effectively improve mixing speed and efficiency, and reduce the peak heat flux.