Simulation of transcritical Diesel jets using the PC-SAFT EoS
A numerical framework has been developed to simulate Diesel injections using the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state (EoS). The Diesel is modelled as a mixture composed by a rather small number of components that accurately replicate its properties. The composition of the Diesel surrogates employed are divided into two types depending on how closely they approximate the real Diesel composition. Despite of applying an advanced molecular theory, practical simulations can be performed reducing the number of times the EoS is solved by calculating the pressure and sonic fluid velocity in the cell centers and performing a reconstruction of these variables at the cell faces. This methodology is found to smooth-out the spurious pressure oscillations associated with conservative schemes used along real-fluid EoS. Furthermore, two shock tube problems are presented to validate the hyperbolic part of the numerical frame-work and evaluate how the number of compounds of the Diesel surrogate employed affects the accuracy of the numerical results. Finally, a two-dimensional simulation of a four component Diesel surrogate injection is included to demonstrate the capability of the developed method to predict Diesel fuel-air mixing. Phase separa-tion is beyond the scope of this research.