Use of surface flow visualization methods in centrifugal pump design

Surface flow patients generated with oils or oil paint have been used in centrifugal pump design for many years. Here it is shown how modern image analysis methods allow quantitative predictions of the corresponding pressure distribution by analyzing surface flow patterns. Further, the surface flow patterns can be used to confirm computational fluid dynamics (CFD) results, improve their boundary conditions and determine their limits of validity. The authors see the need for a new type of boundary condition for CFD packages, in which a measured flow pattern could be used as "input.".