scholarly journals Two Dimensional Flow Analysis of a Laboratory Centrifugal Pump

1990 ◽  
Author(s):  
S. M. Miner ◽  
R. D. Flack ◽  
P. E. Allaire
Keyword(s):  
Velocity Field ◽  
Stagnation Point ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Flow Analysis ◽  
Tangential Component ◽  
Design Flow ◽  
Experimental Results ◽  
Two Dimensional ◽  
Flow Angle

Two dimensional potential flow was used to determine the velocity field within a laboratory centrifugal pump. In particular, the finite element technique was used to model the impeller and volute simultaneously. The rotation of the impeller within the volute was simulated by using steady state solutions with the impeller in 10 different angular orientations. This allowed the interaction between the impeller and the volute to develop naturally as a result of the solution. The results for the complete pump model showed that there are circumferential asymmetries in the velocity field, even at the design flow rate. Differences in the relative velocity components were as large as 0.12 m/sec for the radial component and 0.38 m/sec for the tangential component, at the impeller exit. The magnitude of these variations was roughly 25% of the magnitude of the average radial and tangential velocities at the impeller exit. These asymmetries were even more pronounced at off design flow rates. The velocity field was also used to determine the location of the tongue stagnation point and to calculate the slip within the impeller. The stagnation point moved from the discharge side of the tongue to the impeller side of the tongue, as the flow rate increased from below design flow to above design flow. At design flow, values of slip ranged from 0.96 to 0.71, from impeller inlet to impeller exit. For all three types of data (velocity profiles, stagnation point location, and slip factor) comparison was made to laser velocimeter data, taken for the same pump. At the design flow, the computational and experimental results agreed to within 17% for the velocity magnitude, and 2° for the flow angle. The stagnation point locations coincided for the computational and experimental results, and the values for slip agreed to within 10%.

Two-Dimensional Flow Analysis of a Laboratory Centrifugal Pump

1992 ◽  
Vol 114 (2) ◽  
pp. 333-339 ◽  
Author(s):  
S. M. Miner ◽  
R. D. Flack ◽  
P. E. Allaire
Keyword(s):  
Velocity Field ◽  
Stagnation Point ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Flow Analysis ◽  
Tangential Component ◽  
Design Flow ◽  
Experimental Results ◽  
Two Dimensional ◽  
Flow Angle

Two-dimensional potential flow was used to determine the velocity field within a laboratory centrifugal pump. In particular, the finite element technique was used to model the impeller and volute simultaneously. The rotation of the impeller within the volute was simulated by using steady-state solutions with the impeller in ten different angular orientations. This allowed the interaction between the impeller and the volute to develop naturally as a result of the solution. The results for the complete pump model showed that there are circumferential asymmetries in the velocity field, even at the design flow rate. Differences in the relative velocity components were as large as 0.12 m/s for the radial component and 0.38 m/s for the tangential component, at the impeller exit. The magnitude of these variations was roughly 25 percent of the magnitude of the average radial and tangential velocities at the impeller exit. These asymmetries were even more pronounced at off-design flow rates. The velocity field was also used to determine the location of the tongue stagnation point and to calculate the slip within the impeller. The stagnation point moved from the discharge side of the tongue to the impeller side of the tongue, as the flow rate increased from below design flow to above design flow. At design flow, values of slip ranged from 0.96 to 0.71, from impeller inlet to impeller exit. For all three types of data (velocity profiles, stagnation point location, and slip factor) comparison was made to laser velocimeter data, taken for the same pump. At the design flow, the computational and experimental results agreed to within 17 percent for the velocity magnitude, and 2 deg for the flow angle. The stagnation point locations coincided for the computational and experimental results, and the values for slip agreed to within 10 percent.

scholarly journals Laser Velocimeter Measurements in a Centrifugal Pump With a Synchronously Orbiting Impeller

1990 ◽  
Author(s):  
Ronald J. Beaudoin ◽  
Steven M. Miner ◽  
Ronald D. Flack
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Reverse Flow ◽  
Tangential Velocity ◽  
Velocity Profiles ◽  
Radial Component ◽  
Tangential Component ◽  
Design Flow ◽  
Recirculation Region ◽  
Design Flow Rate

Velocity profiles were measured in the impeller of a centrifugal pump with a two directional laser velocimeter. Blade to blade profiles were measured at four circumferential positions and four radii within and one outside the four bladed impeller. Data is presented herein at two circumferential and three radial locations. The pump was tested in two configurations; with the impeller running centered within the pump, and with the impeller orbiting with a synchronous motion (ϵ/r2). Variation in velocity profiles among the individual passages in the orbiting impeller were found. At design flow rate, these variations ranged from 30 to 60 percent for the radial component, and 15 to 25 percent for the tangential component. Tangential velocity profiles near the impeller exit (r/r2 = 0.973) were near uniform across each individual passage. Differences in the magnitude of the exit tangential velocities among the passages, however, were detected. Systematic differences in the velocity profile shapes of the centered and orbiting impellers were in general not measured, the only exception being at r/r2 = 0.973 at 40% of the design flow rate. At this condition, two distinct radial velocity profiles were measured. Two of the impeller passages of the orbiting impeller contained a recirculation region covering 20–30% of the blade passage while the other two passages contained no recirculation region. The centered impeller also contained this region of reverse flow. Finally, velocity data was numerically integrated to find the forces and stiffnesses due to momentum fluxes on the impeller for the orbiting condition.

Laser Velocimeter Measurements in a Centrifugal Pump With a Synchronously Orbiting Impeller

1992 ◽  
Vol 114 (2) ◽  
pp. 340-349 ◽  
Author(s):  
R. J. Beaudoin ◽  
S. M. Miner ◽  
R. D. Flack
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Reverse Flow ◽  
Tangential Velocity ◽  
Velocity Profiles ◽  
Radial Component ◽  
Tangential Component ◽  
Design Flow ◽  
Recirculation Region ◽  
Design Flow Rate

Velocity profiles were measured in the impeller of a centrifugal pump with a two-directional laser velocimeter. Blade-to-blade profiles were measured at four circumferential positions and four radii within and one outside the four-bladed impeller. Data are presented herein at two circumferential and three radial locations. The pump was tested in two configurations; with the impeller running centered within the pump, and with the impeller orbiting with a synchronous motion (ε/r2 = 0.016). Variation in velocity profiles among the individual passages in the orbiting impeller were found. At design flow rate, these variations ranged from 30 to 60 percent for the radial component, and 15 to 25 percent for the tangential component. Tangential velocity profiles near the impeller exit (r/r2 = 0.973) were near uniform across each individual passage. Differences in the magnitude of the exit tangential velocities among the passages however, were detected. Systematic differences in the velocity profile shapes of the centered and orbiting impellers were in general not measured, the only exception being at r/r2 = 0.973 at 40 percent of the design flow rate. At this condition, two distinct radial velocity profiles were measured. Two of the impeller passages of the orbiting impeller contained a recirculation region covering 20-30 percent of the blade passage while the other two passages contained no recirculation region. The centered impeller also contained this region of reverse flow. Finally, velocity data were numerically integrated to find the forces and stiffnesses due to momentum fluxes on the impeller for the orbiting condition.

Hydraulic Design of Inlet Guide Vane and its Full Flow Passage Numerical Simulation on Centrifugal Pump

2014 ◽  
Author(s):  
Hucan Hou ◽  
Yongxue Zhang ◽  
Zhenlin Li ◽  
Xin Zhou ◽  
Zizhe Wang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Guide Vane ◽  
Hydraulic Performance ◽  
Design Flow ◽  
Inlet Guide Vane ◽  
Hydraulic Efficiency ◽  
Flow Passage ◽  
Setting Angle ◽  
Hydraulic Design

In order to effectively improve hydraulic performance of centrifugal pump on off-conditions, the hydraulic design of inlet guide vane (IGV) was completed by adopting two dimensional theory in-house code based on one kind of IS series of centrifugal pump, which can achieve pre-whirl regulation of centrifugal pump. During design process the trailing edge of vane is assumed as equal velocity moment condition, and the distribution of vane setting angle along meridional streamline is also given as a quartic function firstly, the camber line is then drawn by point-by-point integration method and thickened at both sides along circumferential direction. With local vortex dynamics diagnosis theory, the optimal improvement of vane space shape can be finished by adjusting the design parameters of vane setting angle distribution coefficient ap. The full flow passage numerical simulations of centrifugal pump with IGV device are completed to analyze the influence of pre-whirl regulation on hydraulic performance of centrifugal pump under various pre-whirl angles. The results show that the pre-whirl regulation can improve the hydraulic performance of centrifugal pump on off-conditions. Under the positive pre-whirl regulation conditions, the best efficient point shift to small flow rate zone, and under the negative pre-whirl regulation conditions it moves to large flow rate zone. Compared with the pump without IGV device at the same flow rate condition of 0.8Q (Q the design flow rate), the hydraulic efficiency of centrifugal pump with IGV device improves obviously and reaches up to 1.43%. Meanwhile compared with that installed with the straight vanes designed based on the traditional theory, the inner flow field of centrifugal pump with the designed vanes improves and the overall hydraulic efficiency of centrifugal pump is somewhat increased.

Flow Analysis of a Hydrocyclone Designed to High Oil Content Application

2009 ◽  
Author(s):  
G. M. Raposo ◽  
A. O. Nieckele
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Oil Content ◽  
Flow Analysis ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Tangential Component ◽  
Inlet Flow ◽  
Unit Process ◽  
Inlet Flow Rate

Development of small size and weight separation equipment are crucial for the petroleum off-shore exploration. Since centrifugal fields are several times stronger than the gravity field, cyclonic separation has became very important as a unit process for compact gas-liquid, liquid-liquid and solid-liquid separation. The major difference between the various cyclones is their geometry. Cyclone optimization for different uses is, every year, less based on experiments and more based on mathematical models. In the present work, the flow field inside high oil content hydrocyclones is numerically obtained with FLUENT. The performance of two turbulence models, Reynolds Stress Model (RSM) and Large Eddy Simulation (LES), to predict the flow inside a high oil content hydrocyclone, is investigated by comparing the results with experimental data available in the literature. All models overpredicted the tangential component, especially at the reverse cone region. However, the prediction of the tangential turbulent fluctuations with LES was significant better than the RSM prediction. The influences of the inlet flow rate and hydrocyclone length in the flow were also evaluated. RSM model was able to foresee correctly, in agreement with experimental data, the correct tendency of pressure drop reduction with decreasing inlet flow rate and increasing length.

scholarly journals Experimental Analysis on Pressure Fluctuation Characteristics of a Centrifugal Pump with Vaned-Diffuser

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 126
Author(s):  
Houlin Liu ◽  
Ruichao Xia ◽  
Kai Wang ◽  
Yucheng Jing ◽  
Xianghui He
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Dominant Frequency ◽  
Design Flow ◽  
Signal Source ◽  
Vaned Diffuser ◽  
Impeller Outlet ◽  
Variation Tendency ◽  
Design Flow Rate

Experimental measurements to analyze the pressure fluctuation performance of a centrifugal pump with a vaned-diffuser, which its specific speed is 190. Results indicate that the main cause of pressure fluctuation is the rotor-stator interference at the impeller outlet. The head of the pump with vaned-diffuser at the design flow rate is 15.03 m, and the efficiency of the pump with a vaned-diffuser at the design flow rate reaches 71.47%. Pressure fluctuation decreases gradually with increasing distance from the impeller outlet. Along with the increase of the flow rate, amplitude of pressure fluctuation decreases. The amplitude of pressure fluctuation at the measuring points near the diffusion section of the pump body is larger than other measuring points. The variation tendency of pressure fluctuation at P1–P10 is the same, while there are wide frequency bands with different frequencies. The dominant frequency of pressure fluctuation is the blade passing frequency. The rotor-stator interference between the impeller and the vaned-diffuser gives rise to the main signal source of pressure fluctuation.

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.

Turbulence Measurements in a Centrifugal Pump With a Synchronously Orbiting Impeller

1991 ◽  
Author(s):  
Ronald D. Flack ◽  
Steven M. Miner ◽  
Ronald J. Beaudoin
Keyword(s):  
Centrifugal Pump ◽  
Reynolds Stress ◽  
Flow Rate ◽  
Cross Product ◽  
Design Flow ◽  
Low Flow ◽  
Rate Variation ◽  
Flow Rates ◽  
The Individual ◽  
Design Flow Rate

Turbulence profiles were measured in a centrifugal pump with an impeller with backswept blades using a two directional laser velocimeter. Data presented includes radial, tangential, and cross product Reynolds stresses. Blade to blade profiles were measured at four circumferential positions and four radii within and one radius outside the four bladed impeller. The pump was tested in two configurations; with the impeller running centered within the volute, and with the impeller orbiting with a synchronous motion (ε/r2 = 0.016). Flow rates ranged from 40% to 106% of the design flow rate. Variation in profiles among the individual passages in the orbiting impeller were found. For several regions the turbulence was isotropic so that the cross product Reynolds stress was low. At low flow rates the highest cross product Reynolds stress was near the exit. At near design conditions the lowest cross product stress was near the exit, where uniform flow was also observed. Also, near the exit of the impeller the highest turbulence levels were seen near the tongue. For the design flow rate, inlet turbulence intensities were typically 9% and exit turbulence intensities were 6%. For 40% flow capacity the values increased to 18% and 19%, respectively. Large local turbulence intensities correlated with separated regions. The synchronous orbit did not increase the random turbulence, but did affect the turbulence in the individual channels in a systematic pattern.

scholarly journals Efficiency improvement and evaluation of a centrifugal pump with vaned diffuser

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401982590 ◽  
Author(s):  
Kai Wang ◽  
Yu-cheng Jing ◽  
Xiang-hui He ◽  
Hou-lin Liu
Keyword(s):  
Centrifugal Pump ◽  
Axial Force ◽  
Flow Rate ◽  
Pressure Pulsation ◽  
Energy Performance ◽  
Radial Force ◽  
Design Flow ◽  
Vaned Diffuser ◽  
Original Scheme ◽  
Design Flow Rate

In order to enhance the efficiency of centrifugal pump, the structure of a centrifugal pump with vaned diffuser, whose specific speed is 190, was numerically improved by trimming back-blades of impeller and smoothing sharp corner in annular chamber. The energy performance, the internal flow field, the axial force, the radial force, and the pressure pulsation of the pump were analyzed. Results show that efficiency of the improving scheme 1 under the design flow rate is 77.47%, which can balance 69.82% of the axial force, while efficiency of the improving scheme 2 under the design flow rate is the maximum, which could still balance 62.74% of the axial force. The pressure pulsations of the improving scheme 2 at the typical monitoring points are less than that of the improving scheme 1 and the original scheme. The difference of the radial force peak between the improving scheme 1 and the improving scheme 2 is very small. The vector distributions of the radial force of the improving scheme 1 and the improving scheme 2 are more uniform than that of the original scheme. Considering the efficiency, pressure pulsation, and axial force, experiment measurements on the improving scheme 2 were carried out to verify the effectiveness of the improvement result. Results of energy performance experiment show that efficiency of the improving scheme 2 under the design flow rate is 76.48%, which is 5.26 percentage points higher than that of the original scheme.

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