Optimization of scramjet performance with different fuel injection techniques and flame holder cavities

Abstract

In this research paper an attempt has been made to find out the effect of passive fuel injection and direct fuel injection along with two different cavity flame holders. In this research an innovative cavity flame holder is designed to create more recirculation regions in and around the cavity. Investigation has been extended with an additional cavity flame holder along with direct fuel injection technique. This research has been carried out by solving the compressible flow Favre-averaged equations along with SST k−ω turbulence model, finite rate-eddy dissipation chemistry model and global one step reaction mechanism of fuel and air. From the comparison of numerical results among different combustor configurations, it is identified that the wavy wall cavity design increases the thickness of recirculation region and thereby enhance the growth of shear mixing layer. Consideration of an additional cavity increases the stability of combustion by increasing the residence time of supersonic airstream and also increases the pressure and temperature by creating the more recirculation regions. It is also observed that the combination of both the direct and passive fuel injection techniques enhanced the mixing and combustion efficiency. Finally it is to be concluded that the scramjet combustor with an innovative (wavy wall) cavity design and additional cavity along with direct fuel injection technique is the optimum design to enhance the performance of scramjet.