Characterization of Shock-Induced Mixing Enhancement for Transverse Injection in Scramjet Engines

Fuel mixing plays a key role in successful operation of scramjet engines and the injectors need to be designed to achieve rapid and efficient mixing in a short residence time for efficient supersonic combustion. Among various fuel mixing techniques, shock-induced mixing enhancement for transverse injection is a promising approach due to its high mixing efficiency and capabilities of facilitating ignition and stable combustion. However, the characteristics of flowfields and performance and the relations between flowfields and performance are yet to be understood in detail. The present study conducts a numerical investigation of shock-induced mixing enhancement for two-dimensional angled slot injection in supersonic crossflow in a parametric manner. The impingement location of an oblique shock on the mixing region has been found to have significant influence on the flowfields and performance of shock-induced mixing enhancement, with three different types of interaction with different characteristics of flowfields and performance observed. The intensity of the oblique shock wave has been found to affect mixing enhancement while predominantly determining the total pressure loss. These results obtained in the present study indicate that chemical reaction would need to be taken into account for further accurate evaluation of the performance of shock-induced mixing enhancement approaches.