Thermophysical modeling of trans/supercritical fuel sprays in diesel engines combining volume translation and residual entropy scaling

In the context of the increasing intensification of diesel engines, the extreme thermodynamic conditions within the cylinder pose challenge on the modeling of fuel properties. Accurate modeling of fluid thermophysical properties is crucial in internal combustion engine fuel simulations. In this work, a novel VT-PR equation of state (EoS) is proposed, while retaining the computational advantages of the cubic formulation. In contrast to previous studies, this EoS significantly improves modeling accuracy for fuels under in-cylinder thermodynamic conditions by incorporating a new Gaussian correction function. Furthermore, it has been thoroughly validated for thermodynamic consistency. By integrating residual entropy scaling into this EoS, the derived transport property model accurately represents and reasonably extrapolates in the supercritical region where there is limited experimental data. In a case study, the developed thermophysical property model is utilized in the simulation of engine combustion network (ECN) Spray A, markedly enhancing the prediction accuracy during the initial stages of the spray. This demonstrates its substantial potential for application in numerical simulation.