PARMFLO (Parallel Reacting Multiphase Flow CFD Analysis)
The PARMFLO (PArallel Reacting Multiphase FLOw Computational Fluid Dynamic Analysis ) software is used to solve multiphase reacting flow computational fluid dynamic (CFD) problems using parallel computing techniques. The intent of using a parallel computing code is to significantly reduce the computing time for large (with the number of cells being used on the order of 105 ,106, or more) complex, multiflow problems from several days to one day. It is noted that the code can be run serially (on one machine) if necessary to provide an initial benchmark run, or to check preliminary inputs or debugging. The code can perform steady or transient simulations in 3-D space. The code employs the standard message passing interface (MPI) developed at Argonne for parallel computing with domain decomposition being in one spatial direction. Phases of a flow problem may include an ideal gas mixture with an arbitrary number of chemical species, and dispersed droplet and particle phases. Porous media may be included as packed beds, foams, or monolith catalyst supports. The porous media approach is well suited to the analysis of reactant mixing in the inlet of a catalytic reactor coupled to the product yields created by flowing through a catalyst coated support structure.
The software employs an Eulerian approach and solves the partial differential equations (PDEs) for conservation of mass, momentum, and energy in the dispersed phases. The PDEs are discretized sing a control volume approach to provide a set of linear set of equations that are solved in a iterative process. An alternating direction implicit (ADI) scheme is used for the different domain partitions. The ADI scheme is embedded in an outer Gauss-Siedel approach over different partition planes when boundary neighbor data exchanges occur. A SIMPLER algorithm is used to link the pressure drop to the PDEs. The user can specify material properties such as specific heats, if necessary, as a function of temperature. Running times will depend upon the number of processors used. A sample case with about 240,000 nodes, for a steady state case of the mixing of three fluids using 10 processors, reached reasonable convergence in about 40 seconds. The code is fully operational and a variety of CFD studies have been run using it.
The software can operate on a Pentium III, 800 MHZ, or better with 512 MB or more RAM. For parallel computing, the running set of computers must be networked within the same domain via network connections with a transfer rate of a least 100 Mbps. The code requires Microsoft Windows 2000 or an XP operating system. MPI software is available for free downloads at the MCS web site. The code is 99% FORTRAN 90. A short module defining parallel variables is written in FORTRAN 77, and is required for an MPI header file. Supporting DLLS are written in Visual C 6.0. The maximum number of mesh points is about 100,000-150,000 for machines with 512 MB of RAM, and this can be used to determine the number of processors needed in a parallel solution. A limited graphical user interface (GUI) is available for starting the parallel computation. The code also has a restart feature that can save results if network "glitches" or other problems occur. A text editor is available for defining code operating conditions, boundary conditions, chemistry data, etc. The code can be run as an executable, and DLL libraries for Visual Fortran and the Visual C ++ are provided. The source code is well documented, and a manual is being written.
It is interesting to note that the software can be run directly off the network and use other computers in the network, and this is an excellent use of computer resources in the off hours. A Beouwolf cluster is not necessary. However, there has been a reluctance by some to have their computer used in the off hours because of a fear that their computer may be "corrupted" or cause a failure to occur; such concerns are not warranted.
The PARMFLO pricing is per copy, with pricing being noted in the license for both universities and commercial organizations. Argonne is seeking organizations to use and develop this software for new and novel applications.. . For universities PARMFLO development can represent a good topic for a Masters thesis or Ph.D. dissertation. For a commercial organization interested in developing a unique solution to a commonly encountered problem, PARMFLO may be able to provide a faster solution at a significantly lower cost than some other software packages.