Accuracy details in realistic CFD modeling of an industrial centrifugal pump in direct and reverse modes

Abstract

Numerical computation of the flowfield inside a pump is herein used as a numerical laboratory, subject to the limitations of modeling assumptions and to experimental verification. A numerical computation of the flow inside a real industrial centrifugal pump is performed that includes a very sophisticated geometry. Conversely to other computations, in this test case no simplification of the geometry was introduced. Numerical computations are obtained using Spalart-Allmaras turbulence model. A detailed analysis of the turbulent flowstructure is performed for the design point and two off design conditions. Additional computations were performed in order to compare the numerical and experimental pump characteristics; these were obtained under normalized testing conditions. Further computations are presented for the pump working in reverse turbine mode (PAT). Detailed analyses of the flow allow a comparison of the internal flow losses when the pump is operating in direct and reverse mode. This is also useful to help in the selection of an adequate pump geometry that can work in both modes with best efficiency.

Effect of Velocity Slip on Head Prediction for Centrifugal Pumps as Turbines

“…In the present work, CFD was used for numerical research of PAT. Considering the Direct Numerical Simulation (DNS) is out of range due to the high computer power needed, and Large Eddy Simulation (LES) is currently only feasible for simplified pump elements [19], the computations were performed by means of the Reynolds Average Navier-Stokes (RANS) equations with an appropriate turbulence model. In this study, the ANSYS-CFX was selected for the solution of the steady 3D Navier-Stokes equation.…”

Analysis of Applicability of CFD Numerical Studies Applied to Problem When Pump Working as Turbine

“…These aspects caused the implementation of PAT technology, which increased in recent years in some engineering applications such as irrigation, hydraulic power stations, water supply, and energy recovery systems [6][7][8]. Moreover, water pressure control and water management are applied as environmental solutions according to previous studies [9][10][11][12]. In this context, one of the main goals of previous studies was to obtain performance curves for PATs [7].…”

“…Axial, mixed, and radial PATs have been studied using CFD simulations for fixed and variable speeds [8,10,11]. Results showed good agreement among parameters while comparing simulations with experiments for pump and turbine operation mode highlighted that the hydraulic efficiency is practically the same for both operation mode in some cases.…”

Numerical Simulation of Axial Vortex in a Centrifugal Pump as Turbine with S-Blade Impeller

“…Computational fluid dynamics (CFDs) were adopted extensively in many earlier research studies to investigate the flow behavior of PAT. A detailed analysis of the turbulence flow structure of a pump and its reverse mode were performed by Pascoa et al [13]. Singh and Nestmann [14] revealed the wakes and the corresponding losses (flow separation) at the inlet and exit of a PAT impeller.…”