Evaluation and improvement of robustness, speed, and accuracy of the dod hpcmp create^tm-av kestrel component coffe cfd solver

Conservative Field Finite Elements (COFFE) is a high-order unstructured flow solver using a finite element formulation. Beginning in DoD HPCMP CREATE^TM-AV Kestrel 8.0, it has been implemented in Kestrel as an alternative to the default unstructured solver, KCFD, which uses a cell-centered finite volume formulation. Currently, the implementation of COFFE in Kestrel is second-fourth order accurate spatially and applicable to steady-state RANS applications. However, higher-order time-accurate calculations are in development for LES and DDES applications in Kestrel V10 releases. This paper describes a number of test cases performed with COFFE over a wide range of applications and flow conditions. As a result of these test cases, a number of improvements to the underlying algorithms in the steady-state flow solver have been made, and best practices for mesh generation and solver settings have been determined. As a result, COFFE’s suitability for use as a production CFD solver has been increased greatly. This paper describes the test cases that have been performed, the flow solutions and other solver outputs, and best practices to rapidly obtain accurate solutions in a variety of flow regimes.