Simulation of unsteady 3-D wet-steam flows through three-stage stator-rotor blade rows with equilibrium and nonequilibrium condensations

Unsteady 3-D wet-steam flows through three-stage statorrotor blade rows in a low-pressure steam turbine model developed by Mitsubishi Heavy Industry (MHI) are numerically investigated. In this study, a new and simple meshing strategy is introduced to improve the prediction of end-wall flows near the shroud and the hub. Dry and wet-steam conditions are taken into account and the calculated results changing the grid system are compared with the experiments. As a practical usage, coarse-grid computations using a PC cluster are also conducted and the results are compared with those using a fine grid and a supercomputer. In addition, a super-cooled condition is assumed and the computation is further conducted. Finally, the effect of homogeneous nucleation and the nonquilibrium condensation on the present flow is evaluated.