5.3.5 Activation in PHOENICS

(a) The MFM option

Starting with version 2.2.1 (October 1 1996) the multi-fluid model of turbulence has become a PHOENICS option. There exist therefore:-

• a set of input-file-library examples;
• an EARTH sub-directory /d_opt/d_mfm;
• some within-EARTH coding, embodied in the file mfmlib.obj

(b) How to activate MFM

How the multi-fluid model is activated is best understood by inspection of the MFM Input-file library.

The following features will there be observed:-

Data are transmitted to EARTH by use of the SPEDAT feature. The number of fluids NFLUIDS is set there and also (for the two-dimensional populations used in combustion examples) the values of NFLR and NFLF (the product of which equals NFLUIDS) which represent the sub-divisions in the reactedness and mixture-ratio dimensions.

Variables F1, F2, F3....... F:NFLUIDS: are SOLVEd; and their initial and boundary conditions are set.

The coupling-and-splitting sources are activated by the PATCH(MICROMIX,PHASEM,1,NX,1,NY,1,NZ,1,LSTEP) statements. However. this is a PATCH which (since the issue of PHOENICS 3.5) needs no accompanying COVALs. Its mere existence suffices.

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