To leverage the last two decades' transition in High-Performance Computing
(HPC) towards clusters of compute nodes bound together with fast interconnects,
a modern scalable CFD code must be able to efficiently distribute work amongst
several nodes using the Message Passing Interface (MPI). MPI can enable very
large simulations running on very large clusters, but it is necessary that the
bulk of the CFD code be written with MPI in mind, an obstacle to parallelizing
an existing serial code.
In this work we present the results of extending an existing two-phase 3D
Navier-Stokes solver, which was completely serial, to a parallel execution
model using MPI. The 3D Navier-Stokes equations for two immiscible
incompressible fluids are solved by the continuum surface force method, while
the location of the interface is determined by the level-set method.
We employ the Portable Extensible Toolkit for Scientific Computing (PETSc)
for domain decomposition (DD) in a framework where only a fraction of the code
needs to be altered. We study the strong and weak scaling of the resulting
code. Cases are studied that are relevant to the fundamental understanding of
oil/water separation in electrocoalescers.Comment: 8 pages, 6 figures, final version for to the CFD 2014 conferenc