タービン段における空力特性に与える動静翼列間隔の効果に関する研究（実験及びCFD）

抄録

Measurement and unsteady RANS simulations are performed using a time-accurate and high-resolution flow solver to clarify unsteady flow field inside a single-stage axial turbine. The final goal of this study is to reveal how and to what extent unsteady aerodynamic interaction inside the turbine stage affects the turbine stage efficiency, and the focus in this paper mainly deals with the effect of stator-rotor axial gap. A simple but realistic computational model is constructed, for example the blade-count ratio used in the numerical simulations is almost the same as that of the real turbine concerned. The flow field is also measured using a five-hole Pitot probe placed downstream of the stator vanes as well as the rotor blades. Detailed comparisons between the experimental data and numerical data are then made to elucidate the effect of the axial gap on the stage performance. It follows that the interaction of stator wake or stator passage vortex with rotor secondary flow is one of the key flow events that control the stage aerodynamic performance.