BLADE-ELEMENT PERFORMANCE OF 0.7 HUBTIP RADIUS RATIO AXIAL-FLOW PUMP ROTOR WITH TIP DIFFUSION FACTOR OF 0.43

摘要

A 9-inch-diameter axial-flow pump was tested in water. The double-circular-arc-bladed rotor had a hub-tip radius ratio of 0.7, tip solidity of 1.02, and design D-factors of 0.43 and 0.70 at the tip and hub, respectively. The investigation covered operations under both noncavitating and cavitating conditions. Radial surveys of flow conditions at the rotor inlet and outlet were taken, and performance across a selected number of blade elements was computed and presented.nThe largest variation of blade-element performance parameters with inlet flow occurred in the blade tip region, thus indicating the criticality of design in this area. Over the upper 30 percent of blade height, loss-coefficient distributions with incidence angles for this rotor configuration indicated that positive blade stall (sharp increase in loss coefficient) occurred very close to the minimum-loss incidence angle, but the loss coefficient increased very slowly moving from reference incidence angle toward a negative stall condition.