Cartesian Cut-Cell Method for Axisymmetric Separating Body Flows

Abstract

A method for the calculation of unsteady, axisymmetric compressible flows involving both fixed and separating bodies is presented. The method uses a Cartesian cut-cell mesh approach and high resolution upwind finite volume scheme. A stationary background Cartesian mesh is generated on the computational domain with complex solid geometries represented by different types of cut cell. Solid bodies are allowed to move across the mesh using a finite volume scheme modified to deal with moving boundary problems. The flow solver employed is a MUSCL-Hancock Godunov-type scheme In conjunction with an approximate Riemann solver of the Harten, Lax, and van Leer type (for flow interfaces) and an exact Riemann solver for a moving piston (for fixed or moving solid faces). A cell-merging technique is used to maintain numerical stability in the presence of arbitrarily small cut cells and to retain strict conservation at moving boundaries. The method is applied to a muzzle blast flow and muzzle break problems involving both fixed and separating bodies