Investigation of Periodically Unsteady Flow in a Radial Pump by CFD Simulations and LDV Measurements

The periodically unsteady flow fields in a low specific speed radial diffuser pump have been investigated both numerically and experimentally for the design condition (Q des ) and also one part-load condition (0.5Q des ). Three-dimensional, unsteady Reynolds-averaged Navier―Stokes equations are solved on high-quality structured grids with the shear stress transport turbulence model by using the CFD (computational fluid dynamics) code CFX-10. Furthermore, two-dimensional laser Doppler velocimetry (LDV) measurements are successfully conducted in the interaction region between the impeller and the vaned diffuser, in order to capture the complex flow with abundant measurement data and to validate the CFD results. The analysis of the obtained results has been focused on the behavior of the periodic velocity field and the turbulence field, as well as the associated unsteady phenomena due to the unsteady interaction. In addition, the comparison between CFD and LDV results has also been addressed. The blade orientation effects caused by the impeller rotation are quantitatively examined and detailedly compared with the turbulence effect. This work offers a good data set to develop the comprehension of the impeller-diffuser interaction and how the flow varies with relative impeller position to the diffuser in radial diffuser pumps.

[1]  Andrea Cattanei,et al.  An experimental investigation of stator induced unsteadiness on centrifugal impeller outflow , 1996 .

[2]  Jianjun Feng,et al.  Numerical Investigation on Pressure Fluctuations for Different Configurations of Vaned Diffuser Pumps , 2007 .

[3]  Guy Caignaert,et al.  Rotor-Stator Interactions in a Vaned Diffuser Radial Flow Pump , 2004 .

[4]  H. J. Dohmen,et al.  Qualitative comparison between numerical and experimental results of unsteady flow in a radial diffuser pump , 2007, J. Vis..

[5]  Christian Brix Jacobsen,et al.  Flow in a Centrifugal Pump Impeller at Design and Off-Design Conditions—Part I: Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV) Measurements , 2003 .

[6]  Michel Stanislas,et al.  PIV Measurements in the Impeller and the Vaneless Diffuser of a Radial Flow Pump in Design and Off-Design Operating Conditions , 2002 .

[7]  K. Sato,et al.  Numerical Solution of Incompressible Unsteady Flows in Turbomachinery , 2001 .

[8]  J. Y. Champagne,et al.  Rotor-stator interaction in a centrifugal pump equipped with a vaned diffuser , 2001 .

[9]  Christopher E. Brennen,et al.  Experimental Investigation of Rotor-Stator Interaction in a Centrifugal Pump With Several Vaned Diffusers , 1989 .

[10]  Christopher E. Brennen,et al.  Hydrodynamics of Pumps , 1995 .

[11]  Joseph Katz,et al.  Quantitative Visualization of the Flow in a Centrifugal Pump With Diffuser Vanes—I: On Flow Structures and Turbulence , 2000 .

[12]  A. -R. Akhras,et al.  Internal flow investigation of a centrifugal pump at the design point , 2001 .

[13]  Donald Rockwell,et al.  Flow Structure in a Radial Flow Pumping System Using High-Image-Density Particle Image Velocimetry , 1994 .

[14]  K. Eisele,et al.  Flow Analysis in a Pump Diffuser—Part 1: LDA and PTV Measurements of the Unsteady Flow , 1997 .

[15]  William N. Dawes,et al.  A Simulation of the Unsteady Interaction of a Centrifugal Impeller With Its Vaned Diffuser: Flow Analysis , 1995 .

[16]  J. F. Combes,et al.  Unsteady Flow Calculation in a Centrifugal Pump Using a Finite Element Method , 1996 .

[17]  Friedrich-Karl Benra,et al.  Unsteady flow visualization at part-load conditions of a radial diffuser pump: by PIV and CFD , 2009, J. Vis..

[18]  J. Y. Champagne,et al.  The Flow Rate Influence on the Interaction of a Radial Pump Impeller and the Diffuser , 2004 .

[19]  Hans Josef Dohmen,et al.  Numerical Investigation of the Transient Flow in a Centrifugal Pump Stage , 2005 .

[20]  David Japikse,et al.  Centrifugal pump design and performance , 1997 .

[21]  F. Menter.  Two-equation eddy-viscosity turbulence models for engineering applications , 1994 .

[22]  Jianjun Feng,et al.  Qualitative Comparison of Unsteady Flow between Numerical and Experimental Results in a Radial Diffuser Pump , 2007 .