Introduction to Design and Analysis of High Speed Pumps

Abstract : The physical mechanisms which govern the flow characteristics in a turbo-machine and specifically a pump are complex, numerous and partially explained. Flow conditions are generally three dimensional, viscous and non stationary and for the case of cavitating flow, one have to take into account two or multiphase conditions. The non stationary character of the flow is obvious if one consider rotor-stator or rotor-volute interactions. In the case of non uniform inlet conditions or intrinsic heterogeneity created by off design conditions and/or two phase flow, the phenomena is more complicated to understand. Transient regimes also lead to non stationary phenomena. The correct understanding and evaluation of these physical mechanisms become more and more important because of the high level of concurrence between pump manufacturers. They have to deal with high efficiencies, extended stabilised operating zones, more compact and reliable machines with severe geometrical constrains.