Discussion: “Radial Force on the Impeller of Centrifugal Pumps With Volute, Semivolute, and Fully Concentric Casings” (Biheller, H. Joseph, 1965, ASME J. Eng. Power, 87, pp. 319–322)

The performance and service life of centrifugal pumps can be influenced by the clocking effect. In this study, 3D numerical calculations based on the k-omega shear stress transport model are conducted to investigate the clocking effect in a centrifugal pump. Time-averaged behavior and transient behavior are analyzed. Results show that the optimum diffuser installation angle in the centrifugal pump is [Formula: see text] due to the minimum total pressure loss and radial force acting on the impeller. Total pressure loss, particularly in the volute, is considerably influenced by the clocking effect. The difference in total pressure loss in the volute at different clocking positions is 2.75 m under the design flow rate. The large total pressure loss in the volute is primarily caused by the large total pressure gradient within the vicinity of the volute tongue. The radial force acting on the impeller is also considerably affected by the clocking effect. When the diffuser installation angle is [Formula: see text], flow rate fluctuations in the volute and impeller passage are minimal, and flow rate distribution in the diffuser passage is more uniform than those in other diffuser installation angles. Moreover, static pressure fluctuations in the impeller midsection and the diffuser inlet section are at the minimum value. These phenomena explain the minimum radial force acting on the impeller. The findings of this study can provide a useful reference for the design of centrifugal pumps.

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Study on Radial Forces of Centrifugal Pumps With Various Collectors

ASME-JSME-KSME 2011 Joint Fluids Engineering Conference: Volume 1, Symposia – Parts A, B, C, and D ◽

10.1115/ajk2011-06039 ◽

2011 ◽

Author(s):

Zhongyong Pan ◽

Junjie Li ◽

Shuai Li ◽

Shouqi Yuan

Keyword(s):

Numerical Simulation ◽

Pressure Distribution ◽

Radial Force ◽

Time Dependent ◽

Centrifugal Pumps ◽

Flow Rates ◽

Trade Off ◽

Blade Passage ◽

Design Choice ◽

Radial Forces

Numerical simulation is presented to study the steady and unsteady radial forces in a centrifugal pump with various collectors. The radial forces are obtained by integrating the pressure distribution around the impeller circumference. The calculated radial forces both time-dependent and independent at different flow rates caused by the collectors are compared. The results show that some conclusions do not consistent with the conventional experience as the collectors with double volute and vaned volute significantly decrease the radial forces and the radial force close a circle during the period of one blade passage passing. The combination of impeller and double volute is a trade-off design choice as it has significantly decreased the radial forces than that of single volute and its configuration is more compact than that of vaned collector.

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Study on radial force characteristics of double-suction centrifugal pumps with different impeller arrangements under cavitation condition

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

10.1177/0957650920926823 ◽

2020 ◽

pp. 095765092092682

Author(s):

Yu Song ◽

Honggang Fan ◽

Zhenwei Huang

Keyword(s):

Strong Influence ◽

Radial Force ◽

Force Distribution ◽

Centrifugal Pumps ◽

Cavitation Model ◽

Cavitation Phenomenon ◽

Cavitation Performance ◽

Critical Cavitation ◽

Force Characteristics ◽

Different Parts

Cavitation phenomenon is inevitable in pumps with strong transient characteristics. Due to the presence of vapors, the pressure distribution in the impeller changes greatly, resulting in a different radial force distribution from that in non-cavitation condition. In the present article, the cavitation performance of double-suction pumps with different impeller–vane arrangements is studied using the renormalization group k–& turbulence model and the Zwart–Gerber–Belamri cavitation model. The radial force on the two impellers and the whole pump are calculated and compared under critical cavitation conditions. The radial force on different parts of impellers is investigated in detail. A strong influence of the radial force on the blades is detected for different impeller–vane arrangements. Then, the flow characters are analyzed in the mid-span of volute. The results show that axial flows are detected in volute near the outlet of the impellers, which is the main cause of the “two-impeller-interaction”.

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Radial Force on the Impeller of Centrifugal Pumps With Volute, Semivolute, and Fully Concentric Casings

Journal of Engineering for Power ◽

10.1115/1.3678265 ◽

1965 ◽

Vol 87 (3) ◽

pp. 319-322 ◽

Cited By ~ 12

Author(s):

H. Joseph Biheller

Keyword(s):

Experimental Investigation ◽

Centrifugal Pump ◽

Radial Force ◽

Operating Speed ◽

Centrifugal Pumps ◽

Operating Range ◽

Aspect Ratios ◽

Radial Forces

An experimental investigation of the magnitude and direction of the unbalanced radial force on centrifugal pump impellers was made. Pumps with single volute, semiconcentric and fully concentric casings of several specific speeds, collector aspect ratios, and with both closed and semiclosed impellers were tested over the full operating range. An equation enabling prediction of expected radial forces based only on pump geometry, operating speed, and capacity (expressed as fraction of capacity at best efficiency) is presented.

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

Journal of Fluids Engineering ◽

10.1115/1.3089539 ◽

2009 ◽

Vol 131 (5) ◽

Cited By ~ 32

Author(s):

B. P. M. van Esch

Keyword(s):

Velocity Profile ◽

Radial Force ◽

Rotor System ◽

Flow Profile ◽

Centrifugal Pumps ◽

Mixed Flow ◽

Pipe Bend ◽

Suction Velocity ◽

Suction Flow ◽

Flow Pump

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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The simulation of the service life of the rotary shaft of a centrifugal pump

MATEC Web of Conferences ◽

10.1051/matecconf/201928701025 ◽

2019 ◽

Vol 287 ◽

pp. 01025

Author(s):

Madina Isametova ◽

Rollan Nussipali ◽

Aysen Isametov

Keyword(s):

Service Life ◽

Centrifugal Pump ◽

Safety Factor ◽

Operating Time ◽

Radial Force ◽

Life Safety ◽

Centrifugal Pumps ◽

Computer Technique ◽

Rotor Shaft ◽

Pump Shaft

The article describes an automated calculation of such an essential part of a centrifugal pumps the rotor shaft, so the highest level CAD NASTRAN system PATRAN module was used for the analysis. The computational mechanical scheme was drawn up, the axial and radial force acting on the impeller and the pump shaft were determined. The stress for the maximum feed case are determined. The results of the automated strength calculation were used for further analysis of the service life of the rotor shaft of a centrifugal pump. A computer technique for determining the service life of the shaft is given, taking into account the technological, mechanical conditions of operation and taking into account the projected service life equal to the lifetime of the uranium well. Using the automated MSC FATIGUE module, the number of loading cycles was determined, the service life safety factor was determined, which showed the efficiency of the pump throughout the entire operating time of the uranium well.

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Numerical Simulations on Assembly Modifications for Annular Casing of One Centrifugal Pump

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.516-517.966 ◽

2012 ◽

Vol 516-517 ◽

pp. 966-969

Author(s):

Yi Zhang Fan ◽

Zhi Gang Zuo ◽

Shu Hong Liu ◽

Yu Jun Sha ◽

Yu Lin Wu

Keyword(s):

Numerical Simulation ◽

High Pressure ◽

High Temperature ◽

Numerical Simulations ◽

Centrifugal Pump ◽

Radial Force ◽

Hydraulic Efficiency ◽

Centrifugal Pumps ◽

Safety Factors ◽

Simulation Results

Centrifugal pumps adopt annular casings instead of volute casings when working in high temperature and high pressure conditions, which results in conservative safety factors in sacrifice of hydraulic efficiency. This paper presents numerical simulations on two assembly modification methods for one annular casing imitating the volute casing to improve hydraulic performance. Method one was the eccentric axis method. Method two was the extended vane method. Numerical simulation results, given by CFX, showed that both the two method could increase the hydraulic efficiency and head while rise in radial force was small.

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The Unsteady Flow in a Centrifugal Pump With Special Slope Volute

Volume 1B, Symposia: Fluid Machinery; Fluid Power; Fluid-Structure Interaction and Flow-Induced Noise in Industrial Applications; Flow Applications in Aerospace; Flow Manipulation and Active Control: Theory, Experiments and Implementation; Fundamental Issues and Perspectives in Fluid Mechanics ◽

10.1115/fedsm2013-16292 ◽

2013 ◽

Author(s):

Bo Gao ◽

Ning Zhang ◽

Zhong Li ◽

Minguan Yang

Keyword(s):

Radial Direction ◽

Pressure Fluctuations ◽

Special Kind ◽

Radial Force ◽

Cfd Analysis ◽

Centrifugal Pumps ◽

Flow Rates ◽

Pressure Distributions ◽

Dynamic Forces ◽

Load Component

Conventional single stage centrifugal pumps are mostly designed with a spiral volute. Due to relative movement between impeller and the asymmetric volute the flow at the outlet of the impeller is strongly interacting with the volute flow. The unsteady phenomenon leads to unbalanced radial dynamic forces as well, especially at off-design points, giving rise to pump vibration and hydraulic noises. In order to weaken the unsteady phenomenon, a special kind of slope volute is designed. Different from the spiral one, it keeps the radial size of the volute casing unchanged, but increasing the axial size to make sure the sectional area changing regularly from the tongue to pump outlet. CFD analysis has used to solve the unsteady 3D viscous flow in both conventional and special designed centrifugal pumps with the same impeller for several flow rates. Compared to the spiral volute pump, there’s secondary flow with only one vortex existing in the slope volute. The average pressure and amplitudes of pressure fluctuations keep nearly unchanged along the slope volute wall due to the symmetrical shape in the radial direction. The pressure distributions for both pumps at fBPF are also very different. Interaction of the impeller flow with the tongue is weaken due to the different kind of tongue shape. It has little influence on the interaction flow field in the pump with slope volute. The radial load component always reaches a minimun magnitude at nominal conditions for both pumps. But the traces calculated for the pump with slope vloute are less stretched in the radial direction than those computed for the pump with spiral volute. Results indicate that a lower pulsation of the radial force is expected, and hardly affected by the flow rate for the pump with slope volute.

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