Experimental Study of 3D Pump-Intake Flows with and without Cross Flow

Abstract

Detailed measurements of three-dimensional turbulent flows within a rectangular single-pump bay area of a right-angle water intake model with and without cross flow were obtained using an acoustic Doppler velocimeter (ADV) in order to elucidate swirling flow characteristics within the pump sump. Without cross flow, the pump-approach flow distributions were characterized by nearly uniform streamwise velocities in the pump bay and weak free-surface vortices near the pump column. With cross flow, the three-dimensional mean velocity measurements revealed the existence of a large recirculation zone upstream of the pump column such that strong streamwise velocities were present at higher depths and near the left sidewall, while the reverse current concentrated at lower depths along the right sidewall. Flow patterns in the latter case were also characterized by strong free-surface vortices in the vicinity of the pump column and a strong floor-attached subsurface vortex underneath the pump bell. Uncertainty analysis for ADV velocity measurements showed good quality data, with uncertainty in mean velocities varying from 2.5 to 6.4%. These experimental data were utilized in validating inviscid numerical solutions.