effects of non-equilibrium condensation on deviation angle and performance losses in wet steam turbines

In this paper, effects of non-equilibrium condensation on deviation angle and performance losses of wet stages of steam turbines are investigated. the ausm-van leer hybrid scheme is used to solve the two-phase turbulent transonic steam flow around a turbine rotor tip section. the dominant solver of the computational domain is the non-diffusive ausm scheme (1993), while a smooth transition from ausm in regions with large gradients (e.g. in and around condensation- and aerodynamic-shocks) to the diffusive scheme by van leer (1979) guarantees a robust hybrid scheme throughout the domain. the steam is assumed to obey nonequilibrium thermodynamic model, in which abrupt formation of liquid droplets produces a condensation shock. to validate the results, the experimental data by bakhtar et al. (1995) has been used. it is observed that as a result of condensation, the aerothermodymics of the flow field changes. for example for supersonic wet case with back pressure pb=30 kpa, the deviation angle and total pressure loss coefficient change by 65% and 200%, respectively, with respect to that in dry case.