A hybrid pressure–density-based algorithm for the Euler equations at all Mach number regimes


C. M. Xisto, Dep. de Eng. Electromecânica, Universidade da Beira Interior, R. Mq.s D Ávila e Bolama, 6201-001 Covilhã, Portugal.

E-mail: xisto@ubi.pt


In the present work, we propose a reformulation of the fluxes and interpolation calculations in the PISO method, a well-known pressure-correction solver. This new reformulation introduces the AUSM+ − up flux definition as a replacement for the standard Rhie and Chow method of obtaining fluxes and central interpolation of pressure at the control volume faces. This algorithm tries to compatibilize the good efficiency of a pressure based method for low Mach number applications with the advantages of AUSM+ − up at high Mach number flows. The algorithm is carefully validated using exact solutions. Results for subsonic, transonic and supersonic axisymmetric flows in a nozzle are presented and compared with exact analytical solutions. Further, we also present and discuss subsonic, transonic and supersonic results for the well known bump test-case. The code is also benchmarked against a very tough test-case for the supersonic and hypersonic flow over a cylinder. Copyright © 2011 John Wiley & Sons, Ltd.