349 曲がりダクトによるターボ機械内部の損失生成機構の解明(G05-6 流体機械(1),G05 流体工学)  [in Japanese] 349 INVESTIGATION FOR LOSS GENERATION MECHANISM OF FLOW IN TURBOMACHINERY BY USING CURVED SQUARE DUCT : INFLUENCE OF ROTATION  [in Japanese]

In a passage of turbomachinery, the complex secondary flow is produced by the effects of the centrifugal forces induced by the passage curvature as well as its rotation and the Coriolis force. The passage vortex (PV) in the secondary flow generates a major part of the losses. Curved ducts are considered to be fundamental models to clarify the behavior of PV. In this study, the analyses of the flow within curved duct are performed with the numerical technique in order to examine the effects of the rotational speed on the formation of the passage vortex by relating the curvature of a curved duct to that on the meridional plane of a centrifugal impeller. The computed results revealed the relationships among the centrifugal forces induced by the passage curvature, the Coriolis force caused by the rotation and the formation of PV.