A Finite Volume Chimera Method for Fast Transient Dynamics in Compressible Flow Problems

Abstract

This article deals with fast transient dynamics of compressible flows in which local flow details matter. An overlapping grid Chimera method is proposed in a finite volume framework. Euler's equations are considered, as well as explicit time integration with a second order discretization in time and space. The method is intended to improve the accuracy of a large scale calculation by adding a local grid containing important flow details that alter the flow within the global grid. This paper evaluates the impact of the Chimera exchange on flow dynamics crossing the overlapping grid interface. The proposed Chimera method is assessed using five well-known test cases from the literature. With a second order interpolated solution inside the receiving cells, the method does not alter the order of convergence of the global model. It is able to deal with complex compressible flow structures as well as multi-component flows, and produces numerical solutions with better quality when using a finer local model compared to a single grid computation, providing significant gains in terms of CPU time and memory usage.