シュラウド付き遠心羽根車の通路中間乱流特性に及ぼす流量の影響

抄録

Flow measurements were made at the mid-passage of a shrouded centrifugal impeller, by using a hot-wire anemometer rotated with the same speed as that of the impeller. The measurements were made for a flow rate corresponding to nearly zero incidence angle and two other flows with reduced and increased flow rates. The measurements show that, as the flow rate is reduced, the regions of a low velocity and a dissipation enlarge from the shroud-side to the hub-side near the suction surface and the values of Reynolds normal stresses tend to decrease. The Reynolds shear stressess qualitatively follow the eddy viscosity concept. However, the values of the shear stressess, that can not discuss by only this concept, also appear in the regions influenced by the secondary flow toward suction surface. Near the suction surface, the effects of the flow rate on the shear stresses are remarkable in the cross-component between the passagewise and blade-spanwise directions, but are little in two other cross-components.