Numerical investigation on influence of diamond shaped strut on the performance of a scramjet combustor

The present work discusses the influence of diamond shaped strut profile on combustion characteristics of a supersonic combustor. The 2D DLR scramjet model was used to investigate the effects of parametric variables which include Mach number, wall pressure ratio and inlet temperatures respectively. Further, interaction between shock-shock, shock-shear layer, and shock-near wall boundary layer is also discussed. It has been observed that the fluid flow behind the strut is oscillating while the primary and secondary recirculation region is present along the centre line of the strut. The study reveals that the optimal size of recirculation region is found at Mach number 2.5 which results into stable combustion. It is observed that the combustion efficiency starts to increase at the trailing edge of the strut due to the strong interaction of shock and the performance of a scramjet combustor is found to deteriorate at very high temperatures and very low Mach number. An optimal combustion efficiency equal to 80% has been obtained at Mach = 2.5, T = 696 K and P-j/P-infinity = 0.8 corresponding to minimum pressure loss. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.