Comparison of Shear Layer Dynamics in Reacting and Non-Reacting Bluff Body Flows

We investigate the dynamical impacts of variable temperature, density, and viscosity on the shear layers and recirculation zones created by non-reacting and reacting flow around three-dimensional triangular prism bluff bodies. Both heated and non-heated bluff bodies are studied for the non-reacting cases to examine thermofluidic variations separately from fluid and flow variability due to combustion. All simulations are performed using adaptive mesh refinement (AMR) to locally resolve physics of interest, resulting in the most highly resolved high Reynolds number bluff body simulations to date. We find a resolution-dependent effect of heat transfer on mean flow statistics, including the recirculation zone length, in the non-reacting cases, reminiscent of observations for bluff body stabilized flames. Strong gradients along the boundary and shear layers, which affect the dynamical significance of different terms in the vorticity transport equation, are analyzed to understand the impacts of vortical structures in the shear layer. These results highlight the importance of capturing strong gradients in simulations of bluff body flows, enabled here by the use of AMR.