Effect of variation of temperature on the internal flow characteristics of a strut and cavity-based SCRAMJET combustor

The computational study for strut and parallel cavities Supersonic Combustor Ramjet (SCRAMJET) combustor is executed by adopting Reynolds Averaged Navier Stokes (RANS) equations for compressible and steady flow. The combustion phenomenon in SCRAMJET occurs at supersonic velocities, due to which severe instabilities in the flow is observed. The turbulence in the combustion chamber is addressed by using turbulent energy equations. The static pressure distribution for the selected grid sizes is compared with the experimental results. Furthermore, the study on the effect of variation air inlet temperature to understand its effect on internal flow characteristics and performance of the system keeping the inlet Mach number constant. The simulation results indicate that with the increase in air inlet temperature, the heat release zone shifted downstream. Also, another remarkable observation is the creation of a secondary recirculation region downstream for T = 340 K which is seen for other temperatures. Additionally, it is observed that with the increase of fuel inlet pressure, vortice intensity cornered near the cavity wall increased. The creation of a high heat release zone is confined to the cavities which caused a consistent rise in the combustion performance. At T = 340 K, the highest combustion efficiency of 93.5% is observed among all other temperatures which indicates the rapid mixing of fuel–air in the combustion chamber.