回転曲がりダクトによる遠心羽根車内の二次流れと損失生成機構の解明 : 第2報,入口ピッチ方向速度分布の影響(流体工学,流体機械)

抄録

The passage vortex in a centrifugal impeller is generated by the centrifugal force caused by the curvature of impeller passage and the Coriolis force induced by the rotation, and strongly affects the loss generation in the impeller channel. Therefore, the control of passage vortex results in the reduction of loss generation. In the present study, the flow within the rotating curved duct which is considered to be a simplified model for centrifugal impeller channels was analyzed numerically in order to reveal the effects of the inlet pitchwise velocity distribution on the formation of passage vortex. The computed results revealed that the thicker boundary layer on the suction side wall than that on the pressure side at the inlet of the bend suppresses the development of passage vortex and consequently reduces the associated loss generation. Moreover, the results were examined in detail by relating with the flow in a centrifugal impeller.