Generalizing the Thermodynamics State Relationships in KIVA-3V

Los Alamos National Laboratory, 52 p.The Peng-Robinson equation of state has been implemented into the KIVA-3V code to better handle high-pressure conditions typical of Diesel engine environments. The implementations mod-ify pressure-volume-temperature relationships, specie heats, and departures in internal energy, among other thermodynamic partial derivatives. Computations show that sign cant deviations do occur for progressively heavier hydrocarbons. However, when these hydrocarbons exist in a
mixture with a non-negligible portion of air, the departures from ideal behavior are mitigated.
Internal energy calculations have been extended to allow for pressure effects, but the strongest factor continues to be temperature. Hence departures from ideal behavior in internal energy and related specic heats are minimum.