CFD Solver Benchmark - OpenFOAM and FEATool
To evaluate the efficiency of the OpenFOAM CFD solver one can use the now classic DFG flow over a cylinder CFD benchmark  for which very accurate reference solutions for drag, lift, and pressure difference have been established . The model problem is set up and solved with identical grids and finite element FEM spaces for both the built-in FEATool MATLAB CFD solver and the dedicated OpenFOAM solver. FEATool uses the built-in MATLAB and Octave direct solver which currently defaults to Umfpack, while OpenFOAM uses a finite volume discretizations (FVM) with efficient iterative solvers.
The resulting CPU timings shown in the table and curves below reveal that OpenFOAM scales far better than the built-in CFD solver, about 20 times at the finest grid level (with 4 uniform refinements of the initial benchmark grid). In 3D the savings would be even greater and this also does not account for the memory consumption (OpenFOAM will use significantly less memory than a direct solver like Umfpack). Thus one should definitely consider using OpenFOAM if one has large scale CFD problems to solve.
|2||2.4 s||0.1 s|
|3||4.9 s||0.3 s|
|4||17.9 s||1.2 s|
|5||100.0 s||4.8 s|
The entire benchmarking script has been written as a self contained FEATool MATLAB m-script file and can be downloaded from the link below.
 G. Nabh, On higher order methods for the stationary incompressible Navier-Stokes equations, PhD Thesis, 1998, Universitat Heidelberg. Preprint 42 / 98, 1998.
 V. John, G. Matthies, Higher-order finite element discretizations in a benchmark problem for incompressible flows, International Journal for Numerical Methods in Fluids, 2001, 37:8:885-903.