Thermodynamic Property Calculator

This property calculator was to be used for the engine modeling project in my Thermal-Fluid Systems class in order to allow us to incorporate combustion analysis in the model. We were asked to develop a program that can calculate various thermodynamic properties of a mixture of ideal gases (namely, nitrogen, oxygen, carbon dioxide and water vapor). The specific heats of each gas were calculated based on polynomial correlations in Walsh and Fletcher's Gas Turbine Performance and were integrated in MATLAB to determine the previously mentioned properties. The property of each gas was weighted by its mole fraction in the mixture to determine the value of that property for the entire mixture.

The implementation of the calculator included features to obtain user inputs of molar composition, temperature and pressure, and to display the output if desired (it was not practical to display all the results when the calculator was actually used in the engine model later on). The results were validated with standard values for properties of air over a very large temperature range. Some of these results can be seen in the plot above - the calculator matches expected data with very good accuracy from 0 to 1800 C when air was modeled as a mixture of 79% nitrogen and 21% oxygen. Slight deviations occurred beyond this but they were not outrageous.