UC Irvine

The Soave-Redlich-Kwong cubic equation of state (EoS) was used in real-gas investigations for a mixture of species. An algorithm for a direct solution using a modified version of the Cardano’s method is described in order to solve the cubic EoS more efficiently compared to previous methods. Isentropic, choked flow through a convergent-divergent nozzle was investigated using classical mixing rules and compared to flow with the ideal-gas law. Two novel methods were described to solve for the downstream conditions of a normal shock and the results compared to ideal-gas solutions. A computer script was written to solve the cubic EoS. A wide range of stagnation pressure and stagnation temperatures were investigated to analyze the effects on the real-gas solutions. Upon tabulation of results, it was concluded that most solutions with lower stagnation temperatures and higher stagnation pressures are furthest in value to ideal-gas solutions. However, the range of agreement is dependent upon the species present as well as the concentration of those species in a gas.