Effect of variation of angle of attack on the performance of two-strut scramjet combustor

Computational simulation of Scramjet combustor at Mach 2.5 through two struts and with three angle of attack (alpha = -3 degrees, alpha = 0 degrees and alpha = 3 degrees) have been presented and discussed in the present research article. Here the fuel which is injected through two struts is placed parallel to the air stream. The geometry and model used here is slight modification of the DLR (German Aerospace Center) scramjet model. Steady two and three dimensional (2D and 3D) Reynolds-averaged Navier-stokes (RANS) simulation and SST k-omega turbulence model is used to predict the shock structure and combustion phenomenon inside the scramjet combustor. All the simulations are done by using ANSYS 14-FLUENT code. Eddy dissipation along with finite rate chemistry model is used as combustion model for the present geometry because of the absence of Arrhenius calculations where turbulence controls the reaction rate. The effect of variation of angle of attack on the efficiency of two-strut scramjet combustor is also discussed in the research article. Present results show that the geometry with zero angle of attack i.e. alpha = 0 degrees, have smallest ignition delay and it improves the performance of scramjet combustor as compared to geometry with alpha = -3 degrees and alpha = 3 degrees. The combustion phenomena as well as efficiency is also found to be highest in case of geometry with alpha = 0 degrees. In order to validate the results, the numerical data for single strut injection is compared with experimental result which is taken from the literature. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.