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Equilibrium Fluids: Hot Gases, Combustion Products, etc. Produced Using NASA's CEA program

SINDA/FLUINT 6000 series FPROP DATA blocks accept variable molecular weight fluids: fluids treated as a single species within a fluid submodel, but that might actually be composed of a plethora of constituents of diminishingly small concentration, including ions. The molecular weight of these "pseudo-fluids" can vary as a function of temperature and pressure using the optional VMOLWPT input function. Variable molecular weight fluids are convenient for representing hot combustion gases, ionized air, equilibrium mixtures of dimers, etc. without having to track each species individually, much less create FPROP DATA blocks for each species within the mixture. The main restriction is that each state point must be at chemical equilibrium, since all properties are deterministic functions of temperature and pressure, independent of prior processing history. This restriction will, in general, preclude use at cold temperatures.

A utility has been generated as an adjunct to NASA's chemical equilibrium solver, CEA, such that it can be used to generate variable molecular weight FPROP DATA blocks. CEA was updated to permit generation of large output files. Until NASA incorporates these minor changes into their version, the slightly expanded version of CEA is available from C&R.

Once CEA is run, a separate program (cea2prop) is run that reads CEA's outputs and generates an FPROP DATA block. These utilities are provided as a convenience to the user community, on a "user at your own risk, no warranty" basis. If you update or expand any of these codes, please consider allowing other SINDA/FLUINT users to access them.

Documentation for cea2prop: cea2prop.pdf

PC executables for cea2prop and the revised CEA: pc_executables.zip

Source code for the above: source.zip

A bottom logic insert file that should accompany any FPROP block generated by cea2prop (place with your other fluid property files in the location named in your paths.txt file, perhaps): bottomMW.inc

CEA and cea2fprop sample input and output files: samples.zip