Numerical investigation of wavy wall strut fuel injector for hydrogen fueled scramjet combustor

Abstract

Abstract Mixing and combustion of a fuel with supersonic airstream in a scramjet combustor is a complex phenomenon because of very less resident time of the air in the combustion chamber. Mixing of fuel and air at supersonic speed and the subsequent combustion are greatly affected by the disturbance of the flow field in the form of shock waves, vortices and recirculation regions. In this research paper, the same concept has been considered by introducing an innovative strut fuel injector for the development of more shock waves and streamline vortices. The basic or standard computational domain of the scramjet combustor is considered from the reference of DLR experimental scramjet. The basic scramjet model consists of the wedge-shaped strut fuel injector. In this research, the strut injector has been re-designed such a way that to generate more oblique shock waves. Numerical analysis of the scramjet internal flow field has been performed with basic and innovative strut by solving the Reynolds-averaged Navier-Stokes equations with the help of computational fluid dynamics tool defined as ANSYS-FLUENT 16.0. The internal flow field of scramjet combustor with basic and innovative strut fuel injectors has been visualized from the analysis of pressure, temperature and velocity along with the analysis of flow structure, shock waves, and streamlines vortices. From the analysis of numerical results, it is identified that multiple numbers of oblique shock waves are being generated from the leading curved edge of the newly introduced strut. Both the pressure and temperature of airstream at the entrance of the combustion chamber are higher in the case of the wavy wall strut and it reduces the ignition delay time as compared to the basic strut model.