engleski

Entropy Stable Multi-dimensional Dissipation Function for the Roe Scheme on Unstructured Meshes

Flux difference schemes based on the Roe approximate Riemann solver provide for sharp resolution of shock waves and contact discontinuities. Despite its good properties, the Roe scheme does not possess entropy stability that is required for the scheme to provide physically correct solutions. In addition, since the approximate Riemann solver was developed using one-dimensional considerations, the carbuncle instability appears around stagnation points for mesh-aligned flows. A solution to both entropy stability and the carbuncle problem is considered here. An alternative form of the dissipation function is developed that addresses both problems. The new dissipation function is based on the multidimensional modification to dissipation function of Roe scheme. The new scheme is shown to maintain sharp resolution comparable to the Roe flux difference scheme while satisfying entropy stability and removing the carbuncle type of instability.

Finite Volume; compressible; Roe Scheme; CFD

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