Two-fluid model for simulation of supersonic flow of wet steam within high-pressure nozzles

•Two-fluid model multiphase flow can better predict pressure distributions.•Nucleation process occurs sooner when the superheating level of inlet steam decreases.•Due to release of latent heat the liquid phase becomes hotter than vapor phase.•The effects of slip velocity are very important in high pressure inlet steam.•Liquid mass fraction becomes larger in high expansion rate.

This study presents a numerical simulation of supersonic flow of wet steam within high-pressure nozzles with a non-equilibrium phase change. The simulation based on two-fluid model is carried out to predict the flow characteristics of fluid within high-pressure nozzles by in-house CFD code. The model solves two separate flow governing equations for the compressible, viscous and turbulent vapor and liquid phases. The homogeneous condensation model is applied for modeling the liquid phase formation. Quantitative validation of the numerical model with two high-pressure nozzles was accomplished. The validation of the in-house CFD code proves its usefulness for modeling the steam condensing flows within high-pressure nozzles which are very practical in desalination industry and vapor turbines.