Investigation of thermodynamic properties of real fluids from van der Waals and Dieterici-like equations of state
Mohamm ad Mehdi Papari, Jalil Moghadasi, Falamarz Akbari and Ali Asghar Mohsenipour
The present study is for determining whether the replacement of traditional van der Waals repulsion terms by other repulsion terms will help improve the basic van der Waals and Dieterici-like equations of state. We are also interested in determining whether the Dieterici-type equation can give better results than those based on the van der Waals equation. In this respect, the van der Waals repulsion part of Peng-Robinson (PR) EOS and original Dieterici (D) EOS are replaced by Carnahan-Starling (CS) and Scott (S) repulsion equations. The original and modified EOSs are applied to calculate nearly all thermodynamic properties of five selected fluids. A comparative study of the results shows that firstly Scott repulsion term is an acceptable alternative for traditional van der Waals repulsion equation and secondly van der Waals families EOS predict the literature thermodynamic properties of above-mentioned compounds better than Dieterici types equations of state especially at liquid state.
Keywords: Equation of sate, thermodynamic properties.