Vorticity Dynamics in Bluff Body Stabilized Premixed Flames with External Pressure Gradients and Free-Stream Turbulence

ORAL

Abstract

Previous studies based on direct numerical simulations of statistically planar premixed flames have shown that flame-generated turbulence is small compared to flow-generated turbulence for highly turbulent (i.e., high Karlovitz, low Damkohler) conditions. However, recent computational and experimental studies have indicated that the flame-generated component can be significant in configurations featuring large background pressure gradients. In this study, we use PeleC, a fully compressible reacting flow code featuring adaptive mesh refinement, to study vorticity dynamics in the near-wake region of a bluff-body stabilized premixed flame at near-blowoff conditions. We consider the combined effects of free-stream turbulence and mean background pressure gradients, as well as their cumulative effect, on the balance between flame-generated turbulence attributed to heat release from combustion and flow-generated turbulence inherent to the flow configuration. We describe how different terms in the vorticity magnitude transport equation vary with turbulence intensity and mean pressure gradient and connect these results with observed flame phenomena. Ultimately, this study will inform the development of improved models for large eddy simulations used to model real-world combustion systems.

*This material is based on work supported by the National Science Foundation (NSF) Graduate Research Fellowship Program under Grant No. DGE 2040434. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors(s) and do not necessarily reflect the views of the National Science Foundation. The authors further acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing HPC resources that have contributed to the research results reported within this paper. URL: http://www.tacc.utexas.edu. The authors additionally acknowledge support in part by high-performance computer time and resources from the DoD High Performance Computing Modernization Program.

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Presenters

  • Kelsea J Souders

    • University of Colorado, Boulder

Authors

  • Kelsea J Souders

    • University of Colorado, Boulder

  • Peter E Hamlington

    • University of Colorado Boulder