Numerical simulation of the hydrogen mixing in downstream of lobe strut at supersonic flow

In this work, a computational fluid dynamic approach is employed to investigate the flow and mixing characteristics of the fuel jet released from the trailing edge of the lobe strut at the supersonic free stream. Hydrogen is injected at sonic velocity while the supersonic freestream moves parallelly over the strut. The lobe shape of the strut is selected to generate strong streamwise vortices and consequently to boost the air/hydrogen mixing. The size and strength of the vortices are visualized through the 3-D contour of the mixing zone to reveal the chief effective terms on the fuel distribution inside the combustor. RANS equations with the SST turbulence model are used for the computational simulation of the supersonic air-stream over lobe strut. The impacts of free-stream Mach number and pressure of jet on fuel mixing are also examined. Moreover, the vertical and horizontal injection models are compared to reveal the mixing mechanism in the downstream of the lobe strut. Our results indicate that the vertical edge is more effective than the horizontal edge on the efficiency of the mixing zone. According to our findings, raising the free stream velocity increases the strength of the vortices and consequently, fuel mixing enhances in the downstream of the injector. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.