Experimental and Numerical Investigation of a Centrifugal Pump Working as a Turbine

2009 ◽  
Author(s):  
Joaqui´n Ferna´ndez ◽  
Rau´l Barrio ◽  
Eduardo Blanco ◽  
Jorge Parrondo ◽  
Alfonso Marcos
Keyword(s):  
Numerical Investigation ◽  
Centrifugal Pump ◽  
Static Pressure ◽  
Maximum Amplitude ◽  
Radial Force ◽  
Local Flow ◽  
Sliding Mesh ◽  
Static Pressure Distribution ◽  
Numerical Predictions ◽  
Radial Forces

An experimental and numerical investigation of a conventional centrifugal pump working as a turbine is presented. The numerical simulations were performed with the code Fluent by means of unsteady flow calculations and a sliding mesh technique to account for the impeller-volute interactions. Thus, it was possible to properly simulate the effect on the local flow of the passage of the impeller blades in front of the volute tongue. The numerical results were compared with the experimentally determined performance curves and additionally with the static pressure distribution measured around the impeller periphery. Once validated, the model was used to estimate the steady and unsteady radial forces on the impeller for a number of flow rates. The steady radial force was also experimentally estimated from the static pressure measurements around the periphery of the impeller. The numerical predictions showed that, for the flow interval considered in the present investigation, the unsteady radial force varied between 24% and 54.3% of the steady magnitude, and that its maximum amplitude was reached when the trailing edge of one of the blades was located 3 deg downstream the tip of the tongue.

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.

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.

Status Review for the Prediction Methods of the Radial Force Caused by a Centrifugal Pump or Volute During Off-Design-Point Operation

2018 ◽  
Author(s):  
Mekuannint Messele ◽  
Abraham Engeda
Keyword(s):  
Centrifugal Pump ◽  
Static Pressure ◽  
Experimental Studies ◽  
Radial Force ◽  
Journal Bearings ◽  
Prediction Methods ◽  
Exit Point ◽  
Static Pressure Distribution ◽  
The Status ◽  
Radial Loading

Volutes are often used on the discharge of a centrifugal pump and compressor to provide efficient gathering of flow moving radially outward and direct to a single tangential exit point. To provide this efficiency, volutes are sized to provide near zero circumferential static pressure distribution at the Best Efficiency Point (BEP). However, as the compressor or pump operates away from BEP, a circumferential variation in static pressure is created within the diffuser and is felt by the impeller. This non-uniform static pressure can also be felt in the journal bearings. Accounting for this radial loading is essential when sizing journal bearings for the pump or compressor to work properly. The volute has been the subject of numerous extensive theoretical, numerical and experimental studies, because the volute strongly affects the overall performance, stability, operating range and the location of the best efficiency point of the pump or compressor. This paper reviews the status of methods for predicting the volute-induced radial force and also attempts to provoke renewed interest and possibly encourage more work to contribute towards a more accurate prediction of the volute-induced radial force. Both pumps and compressor are now being built with increasing pressure ratios, higher speeds and larger sizes, thus giving importance to the need for more accurate radial force prediction methods.

Fluid-Dynamic Pulsations and Radial Forces in a Centrifugal Pump With Different Impeller Diameters

2005 ◽  
Author(s):  
Eduardo Blanco ◽  
Rau´l Barrio ◽  
Jorge Parrondo ◽  
Jose´ Gonza´lez ◽  
Joaqui´n Ferna´ndez
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Fluid Dynamic ◽  
Front Wall ◽  
Numerical Predictions ◽  
Radial Forces ◽  
Flow Through ◽  
Radial Gap

A study is presented on the numerical computation of the unsteady flow through a single suction and single volute centrifugal pump equipped with three impellers of different outlet diameter. Computations were performed by means of the Fluent code, solving the 3D URANS equations. The study was focused on the effect of varying the impeller-volute radial gap on the flow perturbations associated to the fluid-dynamic blade-tongue interaction. In order to contrast the numerical predictions, an experimental series of tests was conducted for the pump with the bigger impeller, to obtain pressure fluctuation data along the volute front wall. Finally, the results from the numerical simulations were used to compute the radial forces at the blade passing frequency, as a function of flow-rate and blade-tongue radial gap.

3-D Numerical Simulation on Unsteady Turbulent Flow of Rotational Flow Self-Priming Pump

2012 ◽  
Vol 562-564 ◽  
pp. 899-902 ◽  
Author(s):  
Chun Lin Wang ◽  
Tian Fang Zhang ◽  
Chun Lei Zhao ◽  
Dong Liu
Keyword(s):  
Turbulent Flow ◽  
Static Pressure ◽  
Three Dimensional ◽  
Rotational Flow ◽  
Coupled Models ◽  
Simple Arithmetic ◽  
Sliding Mesh ◽  
Static Pressure Distribution ◽  
Mesh Model ◽  
Interior Flow

The three-dimensional unsteady turbulent flow of rotational flow self-priming pump was simulated by using Reynolds time-averaged N-S equations and the standard k-ε turbulent model, sliding mesh model of static-dynamic coupled models and SIMPLE arithmetic. The static pressure distribution of the pump central rotative surface and relative velocity of the impeller central rotative surface in a complete application cycle were analyzed. The rule of instantaneous head in a impeller channel cycle was studied, and the positions of maximal head and minimal head were analyzed. It revealed that the unsteady method can truly simulate the changes of the rotational flow self-priming pump interior flow, and the unsteady characteristic of interior flow in rotational flow self-priming pump is obvious and it changes as the relative position of impeller and volute change. The change is periodical, and its frequency is relate to the impeller number and the rotate speed of the pump.

Flow at the Centrifugal Pump Impeller Exit With Circumferential Distortion of the Outlet Static Pressure

2004 ◽  
Vol 126 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Soon-Sam Hong ◽  
Shin-Hyoung Kang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Total Pressure ◽  
Static Pressure ◽  
Mean Flow ◽  
Simple Method ◽  
Local Flow ◽  
Flow Angle ◽  
Flow Parameters ◽  
Relative Flow

The effects of circumferential outlet distortion of a centrifugal pump diffuser on the impeller exit flow were investigated. A fence with sinusoidal width variation was installed at the vaneless diffuser exit. The flow field was measured at the impeller exit with and without the fence, using a hot film probe and an unsteady pressure sensor. Flow parameters varied with the circumferential position and the mean flow parameters plotted against the local flow rate at each circumferential position showed loops along the quasi-steady curves, which were obtained from the result without the fence. Simple theoretical calculations were used to predict the velocity components at the impeller exit with the relative flow angle or total pressure assumed. Good result was obtained when the relative flow angle was assumed to vary quasi-steadily, not constant with the local flow rate. The radial velocity was also reasonably predicted when the total pressure was assumed to vary quasi-steadily. A simple method is proposed to predict the impeller exit flow with downstream blockage in two-step sequence: the first step deals with the diffuser alone to obtain static pressure distribution at the diffuser inlet, while the second step deals with the impeller alone to obtain velocity components distribution at the impeller exit.

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.

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.

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