Numerical Study on Shock Train Characteristics in Divergent Channels

In any supersonic intake, the flow decelerates from supersonic to subsonic speed through a constant or divergent channel “isolator” by a series of bifurcated compression shock waves referred to as a shock train. It is important to understand the characteristics of the shock train which occur inside the isolator to improve the performance of scramjet engines. In the present work, numerical simulations were carried out to investigate the characteristics of the shock train occurring in the divergent channels using coupled implicit Reynolds Averaged Navier-Stokes (RANS) equations along with the two-equation k-w SST turbulence model. Results show that the downstream pressure variation causes the shock train length to decrease and the shock structure phenomenon varies from Mach reflection to Regular reflection. The variation of the inlet Mach number has less influence on the shock train length and the location of the shock train is determined by the area ratio. In comparison with the constant area duct, the shock train structure phenomena varies from Mach reflection to regular reflection in the divergent channel. Also, the increase in divergent angle raises the total pressure loss.