A Cartesian cut cell method for compressible 3-D flows involving both static and moving bodies

A 3-D Cartesian cut cell method is described for modelling unsteady compressible flows around complex geometries, either static or in relative motion. Firstly, a background Cartesian mesh is generated on the computational domain and solid bodies are cut out of it. A accurate representation of any solid geometry is achieved by employing different types of cut cell. Secondly, a modified finite volume algorithm is used to deal with any boundaries which are moving with respect to the stationary background mesh. The flow solver employed is an unsplit MUSCL-Hancock Godunov-type method. A cell merging technique is implemented 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 unsteady compressible 3-D flows involving both moving shock and moving bodies.