Effect of hydrogen jets in supersonic mixing using strut injection schemes

Effect of jet schemes of the double-nozzle strut injector on mixing efficiency of air and hydrogen for a scramjet combustor

Modal analysis of mixing characteristics in scramjet combustor with passive struts

Numerical Investigation on the Effect of Variation of Upper Wall Divergence Angle of Parallel Fuel Injection Scramjet Combustor Performance

This numerical study addresses the performance of double ramps in a strut injection scramjet combustor. Reynolds Averaged Navier Stokes (RANS) equations with the Shear Stress Transport SST k- ω turbulence model are used for numerical analysis. The dual ramps are located symmetrically at the top and bottom wall of a scramjet combustor downstream of the strut injector. The influence of the location of ramps in the scramjet combustor is analyzed based on the key parameters such as shock waves, static pressures, and temperature distribution across the combustor, which are verified with available DLR scramjet experimental data that show similar acceptable values within the range. Simulation is extended for the investigation of other configurations. The performance of the scramjet configurations has been analyzed using the variables such as shock patterns, Mach number contours, wall static pressures, mass fractions of the reactants and products, combustion efficiency, and stagnation pressure loss of combustor. Numerical shadowgraph indicates that numerous shock reflections occur for the dual ramp cases that decelerate the combustor’s flow downstream. In addition, the recirculation regions are created for the dual ramp cases, which help in anchoring the flame. The static pressure distributions show the variation of peaks due to shock patterns and their interactions. The combustion efficiency increases as the ramps are positioned downstream of the strut injector. The mass fractions of reactants and products indicate complete combustion of the hydrogen issued from the combustor in the vicinity of the cavities. The total pressure loss for the DLR strut model is comparatively lower than dual ramp cases due to the multiple shocks from the ramp decelerating the flow downstream of the combustor.

Numerical investigations on the influence of double ramps in a strut based scramjet combustor

This paper aims to study the influences of hydrogen jet pressure on flow features of a strut-based injector in a scramjet combustor under-reacting cases are numerically investigated in this study.,The numerical analysis is carried out using Reynolds Averaged Navier Stokes (RANS) equations with the Shear Stress Transport k-ω turbulence model in contention to comprehend the flow physics during scramjet combustion. The three major parameters such as the shock wave pattern, wall pressures and static temperature across the combustor are validated with the reported experiments. The results comply with the range, indicating the adopted simulation method can be extended for other investigations as well. The supersonic flow characteristics are determined based on the flow properties, combustion efficiency and total pressure loss.,The results revealed that the augmentation of hydrogen jet pressure via variation in flame features increases the static pressure in the vicinity of the strut and destabilize the normal shock wave position. Indeed, the pressure of the mainstream flow drives the shock wave toward the upstream direction. The study perceived that once the hydrogen jet pressure is reached 4 bar, the incoming flow attains a subsonic state due to the movement of normal shock wave ahead of the strut. It is noticed that the increase in hydrogen jet pressure in the supersonic flow field improves the jet penetration rate in the lateral direction of the flow and also increases the total pressure loss as compared with the baseline injection pressure condition.,The outcome of this research provides the influence of fuel injection pressure variations in the supersonic combustion phenomenon of hypersonic vehicles.,This paper substantiates the effect of increasing hydrogen jet pressure in the reacting supersonic airstream on the performance of a scramjet combustor.

R. Sivakumar

Papers

Effect of hydrogen jets in supersonic mixing using strut injection schemes

Numerical investigations on the hydrogen jet pressure variations in a strut based scramjet combustor

Numerical Investigation on Pylon and Flush Wall Injection in Cold Coaxial Jets