Investigation of pressure gradient effect on vorticity dynamics and flame stabilization using an in-house LES flow solver

This study presents the numerical investigation of a triangular bluff body wake under the effect of geometry-induced pressure gradients. Large eddy simulations conducted with an in-house flow solver are presented. First, the solution methodology is validated for a nominal configuration using experimental results. Then, the nominal configuration is modified with ±3^◦ behind the bluff body in order to introduce adverse and favorable pressure gradient effect on the mean flow, turbulence and wake structure. Results indicate that the pressure gradient alters the mean flow and wake generation. Due to the adverse pressure gradient, the flow deceleration in the diffuser configuration increases the wake width and deficit thereby wake strength. Whereas, turbulent kinetic energy induced by cross-stream velocity fluctuations is suppressed in the wake region due to the favorable pressure gradient in the nozzle configuration. Suppressed losses due to reduced small scale activities in the favorable pressure gradient are noticed in the mean axial momentum budget.