A finite volume Chimera method for fast transient dynamics in compressible flow problems

International audienceThis article deals with fast transient dynamics of compressible flows in which local flow detailsmatter. An overlapping grid Chimera method is proposed in a finite volume framework. Euler’sequations are considered, as well as explicit time integration with a second order discretizationin time and space. The method is intended to improve the accuracy of a large scale calculationby adding a local grid containing important flow details that alter the flow within the globalgrid. This paper evaluates the impact of the Chimera exchange on flow dynamics crossing theoverlapping grid interface. The proposed Chimera method is assessed using five well-knowntest cases from the literature. With a second order interpolated solution inside the receivingcells, the method does not alter the order of convergence of the global model. It is able todeal with complex compressible flow structures as well as multi-component flows, and producesnumerical solutions with better quality when using a finer local model compared to a single gridcomputation, providing significant gains in terms of CPU time and memory usage