Investigation of the effect of injection diameter on the characteristics of the flowfield of transverse injection into supersonic air crossflow

Due to the fact that the velocity of air flow in the combustion chamber of scramjets is supersonic, so there is not enough time for proper mixing of fuel and air at these high speeds, and studying the process of mixing of fuel and air in this situation is one of the important issues for scramjet engine design. One of the most widely used methods of fuel injection in supersonic flows of scramjet engine combustion chambers is the method of transverse injection into supersonic air crossflow. Since the velocity of the passing air is very high in such streams, it is challenging to achieve a suitable mixture for combustion. In the present work, by solving the three-dimensional Reynolds-Averaged-Navier-Stokes equations with the k-ω sst turbulence model and the ideal gas state equation, the transverse injection domain in the supersonic flow is numerically simulated and the effect of injection diameter is investigated based on the mixing properties such as fuel penetration depth, mixing efficiency, effective mixing area ratio and stagnation pressure losses. After that, results of reactive flow are presented.