Rayan: A Polyhedral Grid Co-located Incompressible Finite Volume Solver (Part I: Basic Design Features)


Department of Mechanical Engineering,Sharif University of Technology


In this work, basic design features of Rayan are documented. One of the new design
features presented in this work is the way Rayan handles polyhedral grids. Grid de nition is combined
with the de nition of the structure of the sparse coecient matrix, thereby releasing a considerable
part of the memory used by the grid to store otherwise required faces belonging to the cell part of the
connectivity description. The key idea is to use a uniform way for creating the structure of the coecient
matrix from the grid connectivity description and to access that data when computing the elements of
the coecient matrix. This saving requires many modi cations to the computational algorithm details,
which are addressed. Computational method features include a SIMPLE-based pressure-velocity coupling
and co-located variable arrangement in which all
ow variables are stored at cell centers, and mass
are stored on face centers. Also handling convective and di usive
uxes is described. The throughput is
benchmark validated and shows second order truncation properties, both in time and space.