Inlet and Outlet Flow Characteristics of Mixed-Flow Pump in Whole Discharge Range

The inlet and outlet flow characteristics were measured over whole discharge range using a mixed flow pump of which specific speed is 830[m,m3/min,rpm]. The hydraulic loss and the angular momentum loss caused by the inlet reverse flow are revealed, and the variation of slip factor for the variation of pump discharge is determined experimentally together with the empirical formulae as for the discharge at the reverse flow onset and the size of an inlet reverse flow region. The measured results reveal that the energy flux which inlet reverse flow takes out of an impeller increases linearly in proportion to the decrease in pump discharge, which causes rapid increase in theoretical head and water power. The influence of a swirling stop mounted in a suction pipe upon head curves is also determined through the examination of velocity distributions of an impeller inlet flow