Performance and Radial Loading of a Mixed-Flow Pump Under Non-Uniform Suction Flow

Many centrifugal pumps have a suction velocity profile, which is nonuniform, either by design like in double-suction pumps, sump pumps, and in-line pumps, or as a result of an installation close to an upstream disturbance like a pipe bend. This paper presents an experimental study on the effect of a nonuniform suction velocity profile on performance of a mixed-flow pump and hydrodynamic forces on the impeller. In the experiments, a newly designed dynamometer is used, equipped with six full Wheatstone bridges of strain gauges to measure the six generalized force components. It is placed in between the shaft of the pump and the impeller and corotates with the rotor system. A high accuracy is obtained due to the orthogonality of bridge positioning and the signal conditioning electronics embedded within the dynamometer. The suction flow distribution to the pump is adapted using a pipe bundle situated in the suction pipe. Results of measurements show the influence of the suction flow profile and blade interaction on pump performance and forces. Among the most important observations are a backward whirling motion of the rotor system and a considerable steady radial force.

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Performance of a Mixed Flow Pump with Varying Tip Clearance: Part 2

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1243/pime_proc_1996_210_050_02 ◽

1996 ◽

Vol 210 (4) ◽

pp. 319-327 ◽

Cited By ~ 7

Author(s):

S Soundranayagam ◽

T K Saha

Keyword(s):

Close Agreement ◽

Tip Clearance ◽

Pump Efficiency ◽

Centrifugal Pumps ◽

Mixed Flow ◽

Loss Distribution ◽

Specific Speed ◽

Flow Pump ◽

Relative Flow

Measurements in a mixed flow pump of non-dimensional specific speed k = 1.89 [ NS = 100 r/min (metric)] are analysed to give loss distribution and local hydraulic efficiencies at different flowrates and values of tip clearance. Fairly close agreement is obtained between the relative flow angles leaving the blading as predicted by simple deviation and slip models and derived from the measurements. The head developed is broken up into two parts: that contributed by Coriolis action and that associated with blade circulation. It is suggested that lift coefficients based on blade circulation are of limited value in selecting blade profiles. The variation of pump efficiency with tip clearance is greater than that reported for centrifugal pumps.

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Energy Performance and Radial Force of a Mixed-Flow Pump with Symmetrical and Unsymmetrical Tip Clearances

Energies ◽

10.3390/en10010057 ◽

2017 ◽

Vol 10 (1) ◽

pp. 57 ◽

Cited By ~ 38

Author(s):

Yue Hao ◽

Lei Tan ◽

Yabin Liu ◽

Yun Xu ◽

Jinsong Zhang ◽

...

Keyword(s):

Energy Performance ◽

Radial Force ◽

Mixed Flow ◽

Flow Pump

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Effect of the runner sealing parameters and operating regime on the radial force on the rotor of a mixed-flow pump-turbine

Hydrotechnical Construction ◽

10.1007/bf01545832 ◽

1994 ◽

Vol 28 (12) ◽

pp. 726-730 ◽

Cited By ~ 1

Author(s):

V. A. Umov ◽

L. A. Cherepovitsyn

Keyword(s):

Operating Regime ◽

Radial Force ◽

Mixed Flow ◽

Pump Turbine ◽

Flow Pump

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Mathematical and Numerical Analysis of Heat Transfer Enhancement by Distribution of Suction Flows inside Permeable Tubes

Mathematical Problems in Engineering ◽

10.1155/2015/953604 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

A.-R. A. Khaled

Keyword(s):

Heat Transfer ◽

Numerical Analysis ◽

Velocity Profile ◽

Heat Transfer Enhancement ◽

Transfer Enhancement ◽

Maximum Enhancement ◽

Enhancement Of Heat Transfer ◽

Suction Velocity ◽

Energy Equations ◽

Suction Flow

Heat transfer enhancement in permeable tubes subjected to transverse suction flow is investigated in this work. Both momentum and energy equations are solved analytically and numerically. Both solutions based on negligible entry regions are well matched. Two different suction velocity distributions are considered. A parametric study including the influence of the average suction velocity and the suction velocity profile is conducted for various Peclet numbers. It is found that enhancement of heat transfer over that in impermeable tubes is only possible with large Peclet numbers. This enhancement increases as suction velocities towards the tube outlet increase and as those towards the tube inlet decrease simultaneously. The identified enhancement mechanisms are expanding the entry regions, increasing the transverse advection, and increasing the downstream excess temperatures under same transverse advection. The average suction velocity that produces maximum enhancement increases as the Peclet number increases until it reaches asymptotically its uppermost value at large Peclet numbers. The maximum reported enhancement ratios for the exponential and linear suction velocity distributions are 17.62-fold and 14.67-fold above those for impermeable tubes, respectively. This work demonstrates that significant heat transfer enhancement is attainable when the suction flow inside the permeable tubes is distributed properly.

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Symmetrical and unsymmetrical tip clearances on cavitation performance and radial force of a mixed flow pump as turbine at pump mode

Renewable Energy ◽

10.1016/j.renene.2018.04.072 ◽

2018 ◽

Vol 127 ◽

pp. 368-376 ◽

Cited By ~ 113

Author(s):

Yue Hao ◽

Lei Tan

Keyword(s):

Radial Force ◽

Pump Mode ◽

Mixed Flow ◽

Cavitation Performance ◽

Flow Pump

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Numerical and Experimental Investigation of Hydrodynamic Forces Due to Non-Uniform Suction Flow to a Mixed-Flow Pump

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2005-77208 ◽

2005 ◽

Cited By ~ 1

Author(s):

B. P. M. van Esch ◽

N. W. H. Bulten

Keyword(s):

Quantitative Agreement ◽

Flow Conditions ◽

Mixed Flow ◽

Uniform Suction ◽

Uniform Distributions ◽

Numerical Studies ◽

Suction Flow ◽

Waterjet Pump ◽

Flow Pump ◽

Entrance Flow

This paper presents an investigation of the effect of a non-uniform suction flow on forces on the impeller of a waterjet pump. In such a pump, used for ship propulsion, the non-uniformity of the suction flow is caused by the boundary layer under the hull of the ship and the shape of the inlet duct. The paper covers both experimental and numerical studies. A model of a mixed-flow waterjet pump is built into a closed-loop test rig. In order to measure the instantaneous forces and bending moments on the impeller, a newly designed co-rotating dynamometer is used, which is built between the impeller and the shaft of the pump. The design of the dynamometer will be presented. Various entrance flow distributions to the pump are achieved by means of a device situated in the suction pipe. In this manner the axial velocity at the inlet of the pump is varied between uniform and non-uniform distributions. Results of measurements show the influence of suction flow and blade interaction on forces. Results of experiments are compared with CFD calculations of a waterjet pump installation with similar entrance flow conditions. Quasi-steady calculations are performed for the pump which is equipped with a vaned stator bowl. Calculations show a good quantitative agreement with measurements.

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Scale Effects in a Mixed Flow Pump: Part 1

Proceedings of the Institution of Mechanical Engineers Part A Power and Process Engineering ◽

10.1243/pime_proc_1986_200_024_02 ◽

1986 ◽

Vol 200 (3) ◽

pp. 173-179

Author(s):

V Ramarajan ◽

S Soundranayagam

Keyword(s):

Reynolds Number ◽

Scale Effects ◽

Reynolds Numbers ◽

Centrifugal Pumps ◽

Mixed Flow ◽

Operating Range ◽

Experimental Range ◽

Specific Speed ◽

Flow Pump

The variation of efficiency and losses over a range of Reynolds numbers has been measured for a mixed flow pump of specific speed 118 r/min for a number of points covering its operating range. The losses have been separated into those of the impeller and volute. The efficiency is seen to show a steady rise throughout the experimental range in comparison with published results for centrifugal pumps which flatten out at higher Reynolds numbers. A distinct hump is seen in many of the efficiency variation curves as well as in the variation of head with Reynolds number. The hump in the efficiency curves seems to be connected with transition to a roughness dominated regime while that in the head variation appears to be connected to changes in circulation. They both occur at different Reynolds numbers and are unconnected with each other. The frictional component of the losses in the volute is small and the losses there seem to be largely independent of Reynolds number.

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