Numerical Simulation of Near-critical Fluids

Supercritical fluids represent an active field of research, interesting from the theoretical point of view, and for industrial applications. We describe a numerical method for the simulation of supercritical fluid flow phenomena, valid for a general real gas equation of state. Three state equations (van der Waals, Carnahan-Starling-De Santis, Redlich-Kwong), describing the thermodynamic behavior of a gas near its critical point are implemented. Numerical tests in the case of the flow through a nozzle and the shock tube problem, show the reliability of the numerical scheme. The response of a supercritical fluid confined into a slab with closed ends, initially at rest in thermodynamic equilibrium, when one boundary is heated, termed Piston effect, is also investigated.