A Ghost-Cell Immersed Boundary Method for High-Speed Reacting Flows

Logan Kunka, Texas A&M University

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Immersed boundary methods allow for the implementation of complex geometries without the need for complex body-fitted or unstructured grids. The study of such complex geometries in reacting flows is critical to combustor applications, including those in supersonic regimes. This new ghost-cell-based immersed boundary method uses high-order interpolation to accurately reconstruct physical boundaries and flow conditions in the presence of shocks. Ghost-cell-based methods eliminate time-stepping constraints found in comparable cut-cell methods. This can be made nearly conservative through iterative methods and is well-suited for hyperbolic problems where each iteration step requires minimal overhead for hydrodynamic updates. This immersed boundary method was implemented in Athena-RFX, a massively parallel, fully compressible, high-order, dimensionally unsplit, reactive-flow code.

Abstract Author(s): Logan Kunka, Alexei Poludnenko