Flow measurements of a centrifugal impeller midpassage with a rotating hot-wire anemometer

摘要

We have constructed a small hot-wire anemometer rotating with a centrifugal impeller, and have measured the mean velocity and the Reynolds stress tensor of the relative flow at the impeller midpassage. The anemometer shows satisfactory performance for wind velocity fluctuation and for linearity between its output and velocity. The mean relative velocity in the impeller passage coincides with that measured previously using a five-hole pressure probe, except that, in the present measurement, the secondary flow is clearer in the region near the shroud surface of the passage. The Reynolds normal stresses are high in the region from the middle blade-to-blade position of the shroud side to the suction surface where loss exists, and the Reynolds shear stresses qualitatively follow the eddy viscosity concept. Therefore, the presented measurement with the hot-wire anemometer seems to be valid for a rotating flow field inside the centrifugal impeller.