Etude de l'écoulement moyen en sortie de roue d'une pompe centrifuge (Roue SHF)

Flow study at the exit of a centrifugal pump impeller

¹ Equipe Hydraulique, I.N.S.A Lyon
² Ingénieur Metraflu, Laboratoire de Mécanique des Fluides et d'Acoustique, E.C.L, UMR CNRS 5509

Abstract

Flows in centrifugal pumps are one of the most complex encountered in turbomachinery. The flow leaving the impeller is affected by the presence of downstream elements such as the diffuser or the volute. This paper presents the results of flow investigation at the exit of a centrifugal impeller run with a vanned diffuser and a spiral casing of industrial type. Velocity and pressure measurements with a directional probe were obtained at three sections located at different circumferential distances from the volute tongue. For each of these sections, traverses were made at two distances from the diffuser vane leading edge. The results showed an asymmetric flow field around the rotor depending mainly on the diffuser arrangement, while the effect of the volute is less pronounced. With the impeller running at partial load, this dependency is influenced by additional phenomena such as back flows and more important gap flows.