A New Approach for Three-Phase Flows

International audienceWe present here a new model to describe three-field patterns or three-phase flows. The basic ideas rely on the counterpart of the two-fluid two-pressure model which has been introduced in the DDT framework, and more recently extended to water-vapour simulations. We show the system is hyperbolic without any constraining condition on the flow patterns. A detailed investigation of the structure of the Riemann problem is achieved. Regular solutions of the whole are in agreement with physical requirements on void fractions, densities and internal energies for a rather wide class of equations of state. Even more, this approach enables to perform computations of standard single pressure three-phase flow models, using relaxation techniques and coarse meshes. A few computational results confirm the stability of the whole approach