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

1965 ◽  
Vol 87 (3) ◽  
pp. 319-322 ◽  
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.

An Experimental Investigation of Radial Thrust in Centrifugal Pumps

1960 ◽  
Vol 82 (2) ◽  
pp. 120-125 ◽  
Author(s):  
A. Agostinelli ◽  
D. Nobles ◽  
C. R. Mockridge
Keyword(s):  
Experimental Investigation ◽  
Centrifugal Pump ◽  
Graphical Form ◽  
Strain Gages ◽  
Centrifugal Pumps ◽  
Speed Range ◽  
Radial Forces ◽  
Specific Speed ◽  
Radial Thrust

An experimental investigation has been conducted to determine the magnitudes and directions of the unbalanced radial forces on centrifugal pump impellers. The work covers single volutes for a wide specific speed range, double volutes, concentric casings, and modifications of the concentric casing. The results are presented in graphical form and are discussed. A method, making use of strain gages, was devised for determining the magnitudes and directions of the resultant radial forces and is described.

Clocking effect in a centrifugal pump with a vaned diffuser

2020 ◽  
Vol 34 (26) ◽  
pp. 2050286
Author(s):  
Fen Lai ◽  
Xiangyuan Zhu ◽  
Yongqiang Duan ◽  
Guojun Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Radial Force ◽  
Design Flow ◽  
Total Pressure Loss ◽  
Inlet Section ◽  
Centrifugal Pumps ◽  
Installation Angle

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.

Hydrodynamic Design of the Volute of a Centrifugal Pump Using CFD

2011 ◽  
Author(s):  
Rouhollah Torabi ◽  
S. Ahmad Nourbakhsh
Keyword(s):  
Viscous Flow ◽  
Centrifugal Pump ◽  
Static Pressure ◽  
Design Method ◽  
Radial Force ◽  
Inverse Design ◽  
Radial Forces ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Inverse Design Method

The objective of this paper is to develop the shape of an existing volute so that the radial forces in off-design condition become minimum. For this purpose 3-D inverse design method based on the 3-D viscous flow calculations was applied to re-design the geometry of the volute of a low specific speed pump. Various aspects of the geometry change independently to achieve the best one which produces less radial force in off design conditions. Measurements included time-averaged values of velocity and static pressure at a large number of locations in the volute.

Numerical Investigation of Viscous Flow in Three Centrifugal Pumps

2012 ◽  
Author(s):  
Carlos Luis Moreno ◽  
Alejandro Fuenmayor ◽  
Gilberto Núñez ◽  
Jesús De Andrade ◽  
Ricardo Noguera ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Viscous Flow ◽  
Centrifugal Pump ◽  
Fluid Viscosity ◽  
Centrifugal Pumps ◽  
Impeller Blade ◽  
Pump Turbine ◽  
Viscous Liquids ◽  
Pump Performance ◽  
Radial Forces

Centrifugal pump performance is affected when pumping viscous liquids, requiring a larger power input than the same pump handling water. In applications of chemical, civil, environmental, and mechanical engineering that involve centrifugal pumps, it is a challenge to accurately estimate and even more of a challenge to improve their performance when handling viscous liquids. When accurate performance data is needed, difficult experiments must be conducted with the operating viscous flow. The extension of the applicability of numerical techniques for solving fluid dynamics (CFD) permits the consideration of these tools as a definite possibility for predicting the performance of centrifugal pumps with viscous flows. The purpose of this study is to perform a 3D-CFD steady-state simulation of three different configurations of centrifugal pumps. The first is an impeller-diffuser pump (ns = 19) taken from an ESP model. The second is a Francis Pump-Turbine (ns = 28). Finally, the third configuration possesses an impeller and volute (ns = 32). The objective is to characterize and evaluate their performances with four different fluids from 1 to 420 cSt. These are: water at 25°C, SAE10 and SAE30 oils, and Fuel Oil Medium (FOM). For water flow conditions, the numerical results were compared with experimental data, and found to be consistent with global performance parameters. With regard to the higher viscosity fluids, the CFD calculation was compared with those obtained through the standard empirical method (ANSI/HI9.6.7). This resulted in good agreement between the performance results. The commercial software ANSYS-CFX was used for the CFD calculations. The resulting pump performance curve (head, hydraulic efficiency and power output) is consistent with that expected by theory. In general, as the viscosity of fluids increases, the hydraulic energy losses increase. Of the three pumps, slip factor for SAE30 oil was larger for all volumetric flows since it features the best guidance of the flow in the impeller blade passage. For the ns32 pump and the pump-turbine ns28, the volute losses rose from water to FOM, just like the impeller hydraulic losses. For these two turbo machines, the impeller losses were larger than volute losses. For the pumps with volute, the effects of fluid viscosity on the radial forces were evaluated. It was found that the radial forces decrease when the viscosity increases. This paper attempts to contribute to a better understanding of fluid dynamics within centrifugal pump impellers handling viscous fluids, and intends to shed more light on the approaches that performance prediction models should follow in the future.

Study on Radial Forces of Centrifugal Pumps With Various Collectors

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.

scholarly journals Experimental and Numerical Investigation of Radial Forces Acting on Centrifugal Pump Impeller

2014 ◽  
Vol 61 (3) ◽  
pp. 445-454 ◽  
Author(s):  
Krzysztof Karaskiewicz ◽  
Marek Szlaga
Keyword(s):  
Centrifugal Pump ◽  
Rectangular Cross Section ◽  
Radial Force ◽  
Axial Thrust ◽  
Pump Impeller ◽  
Ansys Fluent ◽  
Commercial Code ◽  
Radial Forces ◽  
Radial Thrust ◽  
Centrifugal Pump Impeller

Abstract The paper presents the results of measurements and predictions of radial thrust in centrifugal pump with specific speed ns = 26. In the pump tested, a volute with rectangular cross-section was used. The tests were carried out for several rotational speeds, including speeds above and below the nominal one. Commercial code ANSYS Fluent was used for the calculations. Apart from the predictions of the radial force, the calculations of axial thrust were also conducted, and correlation between thrust and the radial force was found. In the range of the measured rotational speeds, similarity of radial forces was checked.

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

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.

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

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.

Analysis of unsteady radial forces of multistage centrifugal pump with double volute

2018 ◽  
Vol 35 (3) ◽  
pp. 1500-1511 ◽  
Author(s):  
Baoling Cui ◽  
Xiaodi Li ◽  
Kun Rao ◽  
Xiaoqi Jia ◽  
Xiaolin Nie
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Static Pressure ◽  
Radial Force ◽  
Radial Vibration ◽  
Flow Rates ◽  
Content Type ◽  
Blade Passing Frequency ◽  
Multistage Centrifugal Pump ◽  
Radial Forces

Purpose Radial vibration of horizontal centrifugal pump has a close association with radial exciting forces. The purpose of this paper is to analyze the unsteady radial force in multistage centrifugal pump with double volute in detail and investigate the relevance of static pressure, radial force and radial vibration. Design/methodology/approach The unsteady numerical simulation with realizable k-ε turbulence model was carried out for a multistage centrifugal pump with double volute using computational fluid dynamics codes Fluent. The performance tests were conducted by use of a closed loop system and performance curves from numerical simulation agree with that of experiment. Vibration tests were carried out by vibration probes instrumented on the bearing cover of pump near no-driven end. Fast Fourier transform was used to obtain the frequency components of radial forces on the impellers from numerical simulation, which are compared with ones of radial vibration from experiment in Y and Z direction. And the static pressure distributions in the impeller were analyzed under different flow rates. Findings The symmetrical double volute can effectively balance radial forces. The maximum radial force and vibration velocity appear at 0.6 Q among the three flow rates 0.6 Q, Q and 1.2 Q. The frequencies corresponding to relatively large amplitude of vibration velocities and radial forces on the impellers in Y direction are blade passing frequency of the impellers. Blade passing frequency of first-stage impeller and shaft frequency are predominating in Z direction. It indicates that the radial vibration of centrifugal pump is closely related to the unsteady radial force. Originality/value The unsteady radial forces of the impeller in multistage centrifugal pump with double volute were comprehensively analyzed. The radial forces should be considered to balance during the design of multistage centrifugal pump.

Computational Fluid Dynamics-Based Pump Redesign to Improve Efficiency and Decrease Unsteady Radial Forces

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Peng Yan ◽  
Ning Chu ◽  
Dazhuan Wu ◽  
Linlin Cao ◽  
Shuai Yang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Centrifugal Pump ◽  
Stokes Equations ◽  
Leading Edge ◽  
Radial Force ◽  
Entropy Generation Rate ◽  
Radial Forces ◽  
Low Efficiency

In this study, a double volute centrifugal pump with relative low efficiency and high vibration is redesigned to improve the efficiency and reduce the unsteady radial forces with the aid of unsteady computational fluid dynamics (CFD) analysis. The concept of entropy generation rate is applied to evaluate the magnitude and distribution of the loss generation in pumps and it is proved to be a useful technique for loss identification and subsequent redesign process. The local Euler head distribution (LEHD) can represent the energy growth from the blade leading edge (LE) to its trailing edge (TE) on constant span stream surface in a viscous flow field, and the LEHD is proposed to evaluate the flow field on constant span stream surfaces from hub to shroud. To investigate the unsteady internal flow of the centrifugal pump, the unsteady Reynolds-Averaged Navier–Stokes equations (URANS) are solved with realizable k–ε turbulence model using the CFD code FLUENT. The impeller is redesigned with the same outlet diameter as the baseline pump. A two-step-form LEHD is recommended to suppress flow separation and secondary flow encountered in the baseline impeller in order to improve the efficiency. The splitter blades are added to improve the hydraulic performance and to reduce unsteady radial forces. The original double volute is substituted by a newly designed single volute one. The hydraulic efficiency of the centrifugal pump based on redesigned impeller with splitter blades and newly designed single volute is about 89.2%, a 3.2% higher than the baseline pump. The pressure fluctuation in the volute is significantly reduced, and the mean and maximum values of unsteady radial force are only 30% and 26.5% of the values for the baseline pump.

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