Performance Analysis of Cavitating Flow in Centrifugal Pumps Using Multiphase CFD

Abstract

A multi-phase CFD method is used to analyze centrifugal pump performance under developed cavitating conditions. The differential model employed is the homogeneous two-phase Reynolds-Averaged-Navier-Stokes equations, wherein mixture momentum and volume continuity equations are solved along with vapor volume fraction continuity. Mass transfer modeling is provided for the phase change associated with sheet cavitation. Using quasi-3D (Q3D) analysis, steady and time-dependent analyses were performed across a wide range of flow coefficients and cavitation numbers. Characteristic performance trends associated with off-design flow and blade cavitation are observed. The rapid drop in head coefficient at low cavitation numbers (breakdown) is captured for all flow coefficients. Local flow field solution plots elucidate the principal physical mechanisms associated with the onset of breakdown.

Novel Design of Centrifugal Pump Impellers Using Generated Machining Method and CFD

“…(13) we obtain If the correction angles at the inlet (a′ 5 i , β 1 ) and the outlet (a′ 5 f , β 2 ) regions are known, the coefficient C 1 , C 2 , C 3 and C 4 in Eq. (10) could easily be found as follows: (15) In this study, the correction angle is a key factor to construct three-dimensional impeller geometry by curve fitting of hub-shroud contours. It is found that the inlet angle and outlet angle defined in the velocity triangle correspond to the first derivative of cubic spline function.…”

“…Some phenomena, such as flow separation and cavitation shown by Pak and Lee (1998), have great effects on the loss of pressure head inside the passage. Medvitz et al (2002) performed study for a better understanding of the physics of cavitation and presented multiphase CFD findings for centrifugal pump analysis. Byskov and Jacobsen (2003) generated a model for centrifugal impeller at design and offdesign conditions.…”

Massively Parallel Simulation of the Characteristics of Cavitation Flow in a Centrifugal Pump Impeller

“…Therefore, it is necessary to study the internal cavitating flow in a centrifugal pump. Medvitz et al [1] analyzed centrifugal pump performance under developed cavitating conditions by a multi-phase CFD method. The mixture momentum and volume continuity equations are solved along with vapor volume fraction continuity.…”

Cavitation flow simulation for a centrifugal pump at a low flow rate

“…The service life of the pumps is then reduced greatly [1,2]. Due to the importance of the cavitation phenomenon and the great process in the cavitation and turbulence models, numerical simulations have been widely used to investigate the cavitation flow field in the pumps [3][4][5][6].…”

“…By using the cavitation model proposed by Kunz et al [7], Medvitz et al [3] calculated the cavitating flow in a centrifugal pump at small cavitation numbers. They analysed the reason why the pump head drops at small cavitation numbers for the off-designed condition, but the assumption of the potential flow in their calculations limits their methods used in more application.…”