Numerical simulations of steady and unsteady two-phase flows using a homogeneous model

The capability of a homogeneous model to simulate steady and unsteady two-phase flows is investigated. The latter is based on the Euler set of equations supplemented by a complex equation of state describing the thermodynamical behavior of the mixture. No equilibrium assumption is made except for the kinematic equilibrium. The return to the thermodynamical equilibrium is ensured by three source terms that comply with the second law of thermodynamics. The numerical code built on the basis of this model has been verified and some validation results are discussed here. The speed of propagation of a pressure signal is first studied and compared with experimental measurements. Then a more complex situation is investigated: SUPERCANON experiment which corresponds to a sudden depressurization of heated water (associated to a Loss Of Coolant Accident, or LOCA). At last, the results of a numerical experiment of heating of flowing water in a pipe are compared to those obtained with an industrial code.