Comparison of physical hydraulic and CFD model measurements of velocity and swirl angle in pump intakes

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Jospeh Orlins, Zachary Taylor, Justin Arnold

Friday 3 july 2015

9:30 - 9:45h at Africa (level 0)

Themes: (T) Special session, (ST) Design of intake stations

Parallel session: 14D. Special session: Design of intake stations

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There is a desire within the industry to apply Computational Fluid Dynamics (CFD) models to pump intakes. In an effort to demonstrate the use of CFD for evaluating acceptance of pump intakes, measurements for two conditions in a physical model of a wet pit pumping station are compared to results from a CFD study of the same pump intake. Quantitative measures of axial and tangential velocities and swirl angles were made in the physical hydraulic model using a 2-D laser Doppler velocimeter (2-D LDV) and traditional swirl meters. The LDV measurements were made at 24 discrete locations at the plane of the pump impeller. The results are compared with those obtained from a steady state CFD model using measurements from 360, 24, and 8 locations. There is general agreement between the physical model and CFD results for axial flow velocities, both in magnitude and spatial distribution. There is poor correlation between the average swirl angles computed from the CFD and those obtained from the physical model using either the swirl angles computed from the discrete 2-D LDV measurements or the traditional swirl meter. These results indicate that additional research is needed to develop application guidelines and acceptance criteria for use of CFD models in evaluating flow entering pump inlets. Keywords: Pump Intakes; Physical Model – CFD Comparison