... was evaluated numerically by using a CFD code. The “sudden-rising head effect” is confirmed to exist at a higher viscosity and a certain large surface roughness. The viscosity and roughness, which make a transition of boundary layer flow pattern in both the impeller and volute to the hydraulically smooth regime...

...Rudolf Bachert; Bernd Stoffel; Matevž Dular The paper deals with unsteady effects of cavitation at the tongue of the volute of a centrifugal pump. For the investigations parts of the volute casing, including the tongue and the hub of the impeller, were made of acrylic glass. Experiments were...