On some simple and robust Riemann solvers for compressible two-phase flows

Abstract

In this work, the HLLC type Riemann solver and the AUSM family are modified for the resolution of the two-phase flows based on a mixture model and a twofluid model. The Eulerian type mixture model and an isentropic six-equation compressible two-fluid model with a non-conservative volume fraction model are chosen as the model equations. The type Tammann equations of state are used to model the real fluids containing the gas, liquid materials. Several stiffened numerical test cases involve two-component air/liquid shock tubes under very high-density ratios (up to 10000) and strong shock waves and contact surfaces. The simulated behaviors near interfaces are verified in the velocity, pressure, density and void fraction profiles. In addition, water hammer, phase separation and gas-solid particle turbulent flows simulations are displayed to highlight the efficiency and accuracy of the methods we propose. The effects of turbulence are evaluated by a RNG ke model. Furthermore, the model of the particle-wall collision is included in the calculations of the gas-particle flow problems to predict erosion.