Investigation on the effects of operating variables on the performance of two-strut scramjet combustor

The two equation SST k-omega turbulence model and the two-dimensional compressible Reynolds-Averaged Navier-Stokes (RANS) equations along with single-step chemical reaction mechanism have been applied to analyze the effect of divergence angle, radius of the strut tip and the half angle of the strut on the combustion enhancement of two-strut scramjet combustor. Here all the simulations are carried out by using ANSYS 14-FLUENT code. Simultaneously, the validation of the present computational simulation for single strut injection has been completed by comparing its result with the available DLR experimental data which is available in the literature. The results are in satisfactory agreement with the experimental schlieren image and pressure, velocity and temperature distribution curve obtained experimentally for the case of single strut combustor. The presence of two struts enhances the mixing and combustion efficiency significantly compared to single strut and the variation of divergence angle, radius of the strut tip and the half angle of the strut also have a great impact on the performance of two-strut scramjet combustor. The present results show that there is an optimal divergence angle for which the performance of the two-strut combustor particularly increases and effective combustion phenomena occur within the combustion region. Again on increasing the radius of the strut tip, the formation of separation region takes place on both the walls of two-strut scramjet combustor which may deteriorate the performance of combustor. Further, combustion phenomena are also affected by the variation of half angle of the strut from 5 degrees to 8 degrees. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.