抄録
The effect of curvilinear element blade in open-type centrifugal impeller was examined in this research using numerical simulation. Four different open-type centrifugal impellers were compared. Two of them were linear element blade impellers, one had a positive tangential lean to the rotation at the outlet and the other had a negative tangential lean. The other two were curvilinear element blade impellers having different tangential lean profiles. Numerical simulation of steady flow was conducted in one-blade path model with inlet, impeller and vane-less diffuser regions. The simulation confirmed that impellers with negative tangential lean profiles improved the stage efficiency under the flow rate condition at the design point. The efficiency increase at the design point was obtained in the impeller region since the negative lean profile reduced the tip-leakage loss near the impeller outlet region.
