A two-phase density-based solver for simulating wet steam flows with non-equilibrium condensation. I. Approach and verification

This paper presents a new two-phase density-based solver based on the finite difference method for simulating high-speed wet steam flows with non-equilibrium condensation. The solver employs the Eulerian–Eulerian approach to model the wet steam flow using a fifth-order accurate weighted compact nonlinear scheme. The phase change of wet steam involves droplet growth in a non-equilibrium condensation process based on the internally consistent classical theory. To speed up computation, a tabulated equation of state approach with curvilinear grids is developed, and an improved Harten-Lax–van Leer-contact-type Riemann solver is used to compute inviscid fluxes. Furthermore, the automatic differentiation technique is applied to avoid manually deriving complicated derivatives when computing flux Jacobian matrices and thermodynamic properties. A numerical investigation is conducted on flow via various kinds of nozzles and blades, and the results demonstrate that the numerical model accurately predicts the behaviors observed in the experiments.