A parallelized, adaptive, multi-grid hybrid unstructured solver for all-speed flows

Abstract

This paper presents a parallelized, solution adaptive, multi-grid hybrid unstructured finite volume solver (UNIC-UNS) for allspeed flows. The methods and techniques applicable for all speeds were implemented in the general-purpose CFD computer code. The hanging node solution adaptation, parallel computing algorithm with multi options of serial, PVM or MPI to accommodate any type of machines, algebraic multi-grid speeding-up convergence method were all facilitated in the solver. With the enhancement of higher order scheme data reconstruction, higher order upwind-biased differencing, multipressure-correction, and Bi-CGSTAB and GMRES matrix solvers, the solver can efficiently and accurately handle flow problems in several cases including benchmark and practical. Very good convergence characteristics have been demonstrated even for highly local enriched grids and high Reynolds number turbulent flow conditions.