Abstract
Various working liquids are pumped up with increasing turbo-pump utilizations in industrial fields. In the case of air/water two phase flow operation for conventional designed turbo-pump, the pumping function disappears even in small void fraction and unstable operation occurs as air-lock phenomenon. On the other hand, for saving energy and materials, small-sized pump has recently been designed under the same specification by compensating higher rotational speed operation. In this case, cavitation problem occurs as deterioration of performance, unstable flow oscillation and erosion. To settle these problems in both cases, it is important to understand flow behavior in the pump and to consider flow mechanism by experimental and computational research works. In the present talk, the flow behaviors in air/water two-phase flow in tested centrifugal impeller and cavitation flow in test inducer, which were experimentally obtained, are shown at first. Then how to find some ideas to improve the performance will be described.
