Accuracy Assessment of Finite-Volume and High-Order Compact Methods for LES of Combustor Flow-Fields

Abstract

The Large-Eddy Simulations (LES) play an important role in the study and design of gas turbine combustors. In order to bring the cost of LES down, compact high-order accurate solvers that can handle complex geometry are a promising method. However, their accuracy vs cost benefit as compared to the standard finite-volume solvers is unclear when it comes to under-resolved hybrid unstructured meshes. These meshes are required to represent the industrial combustor geometries. In this work, a high-order spectral/hp (Nektar++) solver is compared to a standard finite-volume (OpenFoam) solver for a fixed cost. Two combustor-relevant configurations are employed, port-flow and swirling flow. It is found that high-order solver provides moderate accuracy improvements in terms of the mean results and significant improvements for the unsteady results.

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