Enhanced density modeling of hydrocarbon fuels at near supercritical gas-liquid boundary and high-pressure liquid region using a new volume-translated three-parameter cubic equation of state

Abstract

Recently, understanding the Equation of State (EoS) has become increasingly critical for high-fidelity numerical simulations of hydrocarbon-fueled cooling channel and internal combustion engine. However, selecting an appropriate EoS that balances a straightforward algorithm with high predictive accuracy for density across various fluids remains challenging. In this work, integrating and applying simple modifications to the Redlich-Kwong-Peng-Robinson (RKPR) EoS, the generalized Redlich-Kwong (gRK) attraction term, and the Volume-Translation (VT) method present to achieve improvements in three key areas: (1) extending EoS applicability from low to high critical compressibility factor, (2) enhancing density prediction near the supercritical gas-liquid boundary, and (3) improving density prediction within the high-pressure liquid region. To evaluate the performance of the newly developed Volume-Translated Redlich-Kwong Peng-Robinson (VTRKPR) EoS, density of fluids (exo-THDCPD, n-decane, n-dodecane) over a wide range of pressures and temperatures is calculated using various EoSs and the NIST database with the SUPERTRAPP and REFPROP programs. Results confirm that the VTRKPR EoS provides superior density predictions compared to other EoSs.