Implementation of R134a Thermophysical Properties for MARS Application

MARS requires 3 files for analysis: executable MARS file, input, and thermodynamic property file (tpf) for target fluids like light water or heavy water. Most experiments and scenarios were interested in behavior of water so original tpfs were sufficient enough for analysis. As MARS application became wider, needs for other fluid properties rose since MARS do not have extra function to interpret foreign materials that does not have tpf. One way of solving this problem is to generate external tpf file and if successfully implemented, this methodology could widen the application of MARS to other fields of engineering. Thus, this study aims for tpf generation of R134a. The reasons for its selection is because R134a is currently used in refrigerator and frequently used in flow boiling experiment related with heat transfer coefficient and CHF measurement. Generation methods of tpf were discussed. Conventional tpfh2o utilized Gibbs function to calculate the properties. However, since that method could not be applied to other fluids, fitting equation with temperature and pressure variables were applied from R134a property database. Direct implementation of theses equations simplified the structure of main program