A Three-Dimensional Inverse Method for Turbomachinery: Part II—Experimental Verification
The performance of an impeller of a low-speed radial-inflow turbine, designed using a three-dimensional inverse technique, was evaluated experimentally. This performance was compared with that achieved by a rotor typical of the present technology. Besides measuring overall quantities, in special efficiency, some traverses of flow velocity were carried out. The results of the tests showed that the new design had a peak total-to-static efficiency 1.4 points better than the conventional build. The traverses indicated that the level of swirl at exhaust of the new impeller was only half as big as that for the conventional rotor, in spite of the fact that both impellers were designed to have zero swirl at outlet. It is also shown that the rotor loss for the new impeller is considerably lower than for the conventional wheel. This research points to the desirability of using a three-dimensional inverse method for the design of turbomachines with significant three-dimensional flows.