Numerical characterization of pressure instabilities in a vaned centrifugal pump under partload condition

This paper studies the hysteresis/saddle phenomena of the head-drop in a scaled model pump turbine using CFD methods. These lag is induced by complicated flow patterns, which influenced the reliability of rotating machine that was analysed by a commercial code with DES model for computing turbulence. Analyses were carried out on the pressure signals both in frequency and time-frequency domains at full and part load conditions. The results highlighted the remarkable interaction between the unsteady structures in diffuser and return.