Toshihiro Miyawaki

Unsteady Wake and Vortex Interactions in 3-D Steam Turbine Low Pressure Final Three Stages

A practical unsteady 3-D wet-steam flow through stator-rotor blade rows in a low-pressure steam turbine final three stages is numerically investigated. In ASME Turbo Expo 2013, we presented numerical results of unsteady 3-D wet-steam flows through three-stage stator-rotor low-aspect blade rows in a low-pressure steam turbine model designed by Mitsubishi Heavy Industry (MHI) assuming nonequilibrium condensation. The last study is extended to the final three stages with large aspect blade rows. The discussion in this paper is mainly focused on the effect of unsteady wake and vortex interactions on nonequilibrium condensation computed by our in-house code “Numerical Turbine System (NTS)”. In addition, the NTS and the future perspective are also briefly introduced.Copyright

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 stator-rotor 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.Copyright

Development and Verification of Ultra-Long-Blade for Next Generation Steam Turbine

Mitsubishi Heavy Industries, Ltd. (MHI) has developed “LP-End Blades Series” by employing the ISB (I ntegral S hroud B lade) structure and has lead high efficiency and reliability of the steam turbine. The latest technology has been integrated into Ultra-Long-Blades design for the next generation’s steam turbine. This paper describes the design summary of 3600rpm-50inch/3000rpm-60inches and 1800/1500rpm-74/62inches Blades and results of the verification tests.Copyright

Unsteady Wet-Steam Flows Through Low Pressure Turbine Final Three Stages Considering Blade Number

Unsteady three-dimensional wet-steam flows through stator–rotor blade rows in the final three stages of a low-pressure steam turbine, taking the blade number into consideration, are numerically investigated. In ASME Turbo Expo 2014, we presented the numerical results of the unsteady flow assuming the same blade number. Here, this previous study is extended to flow simulations using the real blade number. The flows under three flow conditions, with and without condensation and considering the same and real blade numbers are simulated, and the numerical results are compared with each other and with the experimental results. Finally, the effect of the blade number on unsteady wet-steam flows in real low-pressure steam turbines is discussed.Copyright