Steam turbines are critical power generation equipment in electric power industry. Understanding water vapor condensation flow is important to improve efficiency and safety of steam turbines. Due to complexity of high speed condensation flow in steam turbines

no universally accepted nucleation model is available at present and current numerical models usually neglect vapor-liquid slip. Considered steep distribution and change sensitivity of condensing parameters

a double fluid numerical model of shear stress transport (SST) k-ω-kd two-phase turbulence

which can not only describe transonic flow of compressible gas accurately but also capture parameter jump instantly

was used to analyze condensation flow characteristics in turbine rotor blade tip section. The study revealed influence of pressure ratio on non-equilibrium condensation flow characteristics of wet steams and summarized changing patterns of surface pressure

nucleation rate

humidity

and number of water droplets. Results showed that calculation of pressure ratio at compression surface was in good agreement with experimental data under various operating conditions

although some error was observed in the second half of suction surface. The two fluid numerical model was applicable to both overheating operation and condensations with slight overcooling inlet. But pressure jump caused by condensation shock could hardly be caught for large overcooling inlet. Shock wave interference and vortex mixing had a great influence on distribution of water droplets.