Numerical and Experimental Investigations of the Cavitating Flow in a Centrifugal Pump Impeller

Abstract

This paper presents numerical simulations and experimental investigations of the cavitating flow through a centrifugal pump impeller of low specific speed. The experimental research was carried out at the Pfleiderer-Institute of the Technical University of Braunschweig, while the numerical simulations were performed at the Institute for Hydraulic Machinery and Plants at the Technical University of Munich (LHM). The cavitation model used is based on bubble dynamics and is able to describe the complicated and transient growth and collapse of the cavitation bubbles. The model has been implemented in the 3D CFD-code CNS3D developed at the LHM. The CNS3D-code has been applied to simulate the cavitating flow through a centrifugal pump impeller. The computed pump head, incipient NPSH and three-percent head drop are compared to the experimental data. Also the pressure distributions measured on the blades are compared with the computed ones. Finally, the numerically investigated void fraction distributions are shown in comparison with pictures of the cavitation zones on the blade.

Experimental Investigation and Passive Flow Control of a Cavitating Centrifugal Pump

“…The pressure at the examined pump inlet is measured by the absolute pressure transducer (2). Furthermore, the study of cavitation is realized applying a wide range of pressures at the pump inlet that can be set by changing the pressure in the supply tank with the aid of a vacuum pump (3). The fluid temperature is measured by a temperature sensor (4) and is kept almost constant and equal to 25 • C. The fluid level in the supply tank is read from the level meter (5) and the fluid-free surface pressure is measured by a vacuum-pressure gauge (6).…”

“…Hofmann et al [2] studied experimentally the cavitation of two centrifugal pumps that can hold different runner geometries as well as different leading edge geometries within the same runner. Frobenius et al [3] realized numerical simulations and experimental investigations of the cavitating flow through a centrifugal pump impeller of low specific speed. Coutier-Delgosha et al [4] investigated a special test pump with two-dimensional curvature blade geometry in cavitating and noncavitating conditions using different experimental techniques.…”

On numerical simulation of cavitating flows under thermal regime

“…As shown by [23], for some cases, cavitation models of [19,20] and [22] seem to provide very similar results. Inertial growth models have been also massively employed for the simulation of isothermal cavitating flow through turbopump inducers [24], propellers [25], centrifugal pumps [26,27], hydrofoils [28,29,30] and fuel injectors [31]. For the simulation of cavitating flow in cryogenic fluids, [32] and [33] use the formulation proposed by [21].…”

Computational cavitation flows at inception and light stages on an axial-flow pump blade and in a cage-guided control valve

“…CFD studies based on the continuum approach have been applied by various authors for various fluid machinery and devices. Cavitating pressure distributions on axial pump hydrofoils [1,3,4,5] , head drops of centrifugal pump [9,10] and turbo inducers [2,11] have been the major subjects of application. High pressure injection nozzle flow with a pressure reduction from 800 bar to 11 bar [8] , rocket feed devices flow of cryogenic liquid [7] , and bubble dynamics of shock wave lithotripsy [12] are interesting subjects to be developed.…”