scholarly journals Design and Manufacture of a Water Pump to Study the Effect of Impeller Blades Number on the Pump Performance

2021 ◽  
Vol 2 (2) ◽  
pp. 1-9
Author(s):  
Abdlmanam Elmaryami ◽  
Abdulla Sousi ◽  
Magdi E. M. El-Garoshi ◽  
Abdelkareem Aljair ◽  
Ahmed Almasry ◽  
...  
Keyword(s):  
Secondary Flow ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Experimental Results ◽  
Water Pump ◽  
Velocity Head ◽  
Pump Performance ◽  
Design And Manufacture

In this study, the flow rate, velocity, head, and power in a designed and manufactured centrifugal water pump were studied and determined experimentally. The effect of the impeller with different blades on the centrifugal pump performance has been investigated. Three different impellers with 4, 5, and 6 blades are tested to determine the number of the optimum blades. The experimental results showed that the flow rate, velocity, heat, and power are higher for the case of the impeller with 6 blades than that for the two cases of 4 and 5 blades. The losses decrease by increasing the number of the blades due to the reduction of the secondary flow for a certain limit. The experimental results showed better centrifugal water pump performance when an impeller with 6 blades is used.

EXPERIMENTAL INVESTIGATION OF ENHANCEMENT IN EFFICIENCY OF CENTRIFUGAL PUMP BY REDUCTION IN CAVITATION OF PUMP

2021 ◽  
Vol 5 (10) ◽  
Author(s):  
Gaffar G. Momin
Keyword(s):  
Experimental Investigation ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Rate Control ◽  
Flowing Liquid ◽  
Discharge Flow ◽  
Pump Performance ◽  
Cavitation Phenomenon ◽  
Discharge Flow Rate ◽  
Flow Rate Control

Cavitation phenomenon is basically a process formation of bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapour pressure and it is the most challenging fluid flow abnormalities leading to detrimental effects on both the centrifugal pump discharge characteristics as well as physical characteristics. In this low pressure zones are the first victims of cavitation. Due to cavitation pitting of impeller occurs and wear of internal walls of pumps occurs due to which there is creation of vibrations and noize are there. Due to this there is bad performance of centrifugal pump is there. Firstly, description of the centrifugal pump with its various parts are described after that pump characteristics and its important parameters are presented and discussed. Passive discharge (flow rate) control methods are utilized for improvement of flow rate and mechanical and volumetric and overall efficiency of the pump. Mechanical engineers is considering an important phenomenon which is known as Cavitation due to which there is decrease in centrifugal pump performance. There is also effect on head of the pump which is getting reduced due to cavitation phenomenon. In present experimental investigation the cavitation phenomenon is studied by starting and running the pump at various discharges and cavitating conditions of the centrifugal pump. Passive discharge (flow rate) control is realized using three different impeller blade leading edge angles namely 9.5 degrees, 16.5 degrees .and 22.5 degrees for reduction in the cavitation and increase the of the centrifugal pump performance at different applications namely, domestic, industrial applications of the centrifugal pump.

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%.

scholarly journals Analysis of the number and angle of the impeller blade to the performance of centrifugal pump

2021 ◽  
pp. 62-68
Author(s):  
Sugeng Hadi Susilo ◽  
Agus Setiawan
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Flow Simulation ◽  
Maximum Output ◽  
Centrifugal Pumps ◽  
Impeller Blade ◽  
Pump Performance ◽  
Solid Works ◽  
Discharge Pressure

The paper discusses the performance of the pump in relation to the impeller. The impeller section is determined by the number and angle of the blades. Therefore, the purpose of this study was to analyze the role of the number and angle of impeller blades on the performance (discharge and discharge pressure) of centrifugal pumps based on experiments and simulations. The method used is experiment and simulation. Using a centrifugal pump type GWP 20/4 SW, Maximum Output: 6.5 HP/3500 rpm, Inlet/Outlet: 2 Inch, Dimensions: 475x375x370 mm. Experiments and simulations by varying the number of blades 2, 4, and 6 with a blade tilt angle of 130°, 150°, and 160°. For flow simulation using solid works program. The results show that pump performance is related to discharge pressure, impeller with 2-blades and an angle of 130° the pressure increases 0.45–2.45 bar, for 150° increases 0.14–2.96 bar, and 160° increases 0.29–3.07 bars. For a 4-blade impeller and an angle of 130°, the pressure increases by 0.48–3.12 bar, for 150° it increases by 0.39–3.39 bar, and for 160° it increases by 0.36–3.48 bar. While the impeller for 6-blades with an angle of 130° the pressure increases from 0.6 bar to 3.72 bar, for 150° increases from 1.36 to 4.34 bar, and 160° increases by 0.36–4.74 bar. While it related pump performance to flow rate, increasing the number of blades causes a decrease in flow rate. The highest flow rate is in a 2-blade impeller with a blade angle of 130° is 404.91 l/s. The lowest flow rate is on a 6-blade impeller with an angle of 160° is 279.66 l/s

scholarly journals Influences of Diffuser Vanes Parameters and Impeller Micro Grooves Depth on the Vertically Suspended Centrifugal Pump Performance

2019 ◽  
Vol 35 (5) ◽  
pp. 735-746
Author(s):  
D. Khoeini ◽  
E. Shirani
Keyword(s):  
Experimental Data ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Numerical Results ◽  
Geometric Parameters ◽  
Profound Impact ◽  
Pump Performance

ABSTRACTEffects of geometric parameters of diffuser vanes as well as impeller micro grooves depth on the performance of a vertically suspended centrifugal pump have been studied. Different diffuser vanes height,leading angles, trailing angles, wrapping angles and furthermore, impeller micro grooves depths have been analyzed thoroughly. Numerical results have been verified by comparing experimental data. Results, without considering cavitation, reveal that diffuser vanes height has the profound impact on the vertically suspended centrifugal pump performance followed by vanes wrapping angle. Additionally, it is observed that delivered head and efficiency of micro-grooved impellers reduce more by flow rate enhancing rather than that of the original impeller.

Centrifugal Pump Pressure Pulsation Prediction Accuracy Dependence Upon CFD Models and Boundary Conditions

2009 ◽  
Author(s):  
Sang Hyun Park ◽  
Gerald L. Morrison
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Mass Flow Rate ◽  
Centrifugal Pump ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Pulsation ◽  
Cfd Simulations ◽  
Pump Performance ◽  
Inlet Condition

Unsteady CFD simulations for a low specific speed open faced impeller centrifugal pump operating with and without balancing holes and having cut-away sections of the impeller are performed and compared to experimental data obtained using the actual pump simulated. For this simulation, the entire pump from suction inlet to exit flange is modeled. General pump performance characteristics are compared between the actual pump and the simulation. Pressure pulsation data are recorded at various locations in the pump using flush mounted pressure transducers and directly compared to the simulation results. Pressure spectrum data are used to evaluate the effects of three different boundary conditions upon the accuracy of the pressure pulsation simulations as well as the overall pump performance. These boundary conditions are a) fixed inlet and exit pressure, b) mass flow rate inlet condition with outflow exit, and c) target mass flow rate inlet with outflow exit which lets the inlet pressure fluctuate. All of these are available in the commercial CFD package utilized. Based upon comparisons between CFD simulations and experimental data for both the steady and unsteady conditions, the mass inlet condition is found to produce the best overall results for the installed pump.

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.

Investigation of the Motion of Bubbles in a Centrifugal Pump Impeller

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Henrique Stel ◽  
Edgar M. Ofuchi ◽  
Renzo H. G. Sabino ◽  
Felipe C. Ancajima ◽  
Dalton Bertoldi ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Operating Conditions ◽  
Impeller Speed ◽  
Pump Impeller ◽  
Pump Performance ◽  
Liquid Flows ◽  
Centrifugal Pump Impeller

Centrifugal pumps operate below their nominal capacity when handling gas–liquid flows. This problem is sensitive to many variables, such as the impeller speed and the liquid flow rate. Several works evaluate the effect of operating conditions in the pump performance, but few bring information about the associated gas–liquid flow dynamics. Studying the gas phase behavior, however, can help understanding why the pump performance is degraded depending on the operating condition. In this context, this paper presents a numerical and experimental study of the motion of bubbles in a centrifugal pump impeller. The casing and the impeller of a commercial pump were replaced by transparent components to allow evaluating the bubbles' trajectories through high-speed photography. The bubble motion was also evaluated with a numerical particle-tracking method. A good agreement between both approaches was found. The numerical model is explored to evaluate how the bubble trajectories are affected by variables such as the bubble diameter and the liquid flow rate. Results show that the displacement of bubbles in the impeller is hindered by an increase of their diameter and impeller speed but facilitated by an increase of the liquid flow rate. A force analysis to support understanding the pattern of the bubble trajectories was provided. This analysis should enlighten the readers about the dynamics leading to bubble coalescence inside an impeller channel, which is the main reason behind the performance degradation that pumps experience when operating with gas–liquid flows.

Transient Characteristics of a Centrifugal Pump at Rapid Startup

2019 ◽  
Author(s):  
Teiichi Tanaka ◽  
Michiya Tabaru
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Thrust Force ◽  
Experimental Results ◽  
Operating Point ◽  
Axial Thrust ◽  
Transient Characteristics ◽  
Transient Period ◽  
Large Flow

Abstract Experimental and CFD studies were carried out on transient behavior of a centrifugal pump at rapid startup. Relationship between the transient characteristics and a flow field in the centrifugal pump was investigated during transient period of the centrifugal pump from experimental results. A single-stage, volute type centrifugal pump is used for the experiments. The pump is equipped with transparent impeller, casing, suction pipe and discharge pipe for PIV in the future. The test setup is a closed-loop and consists of a suction tank, a test pump, an ultrasonic flow meter and a flow control valve. Instantaneous pressure and flow rate were measured at suction and discharge ports with rotational speed during the transient period. The pump suction and delivery pressures were measured using strain gauge type pressure transducers. Unsteady flow rate was calculated from pressure difference between two pressure measurement points in straight pipe of the pump suction lines using the difference of inertia force. The three-dimensional incompressible flow calculation of the test pump is performed using ANSYS® CFX 17.1. The CFD domain is consisted of a pump suction pipe, a pump casing, an impeller and a pump delivery pipe. For all computations, a block structure mesh of around 1,550,000 elements has been used. The mesh is created with the mesh generator ANSYS® ICEM CFD Ver.17.1. Frozen Rotor Method is used for the steady state calculation, and Transient Rotor Method is used for the unsteady calculation. The standard SST model is used for turbulence modelling. Boundary conditions of the pump inlet and outlet are used the time history of total head and mass flow rate obtained from experiment result, respectively. The variation of pump operating point, torque and axial thrust force during transient period were related to the time-dependent flow field, which was investigated using CFD, in the pump. As results of the present study, it was shown that the pump operating point in experiment were larger than quasi-steady one at early transient stage, and then the pump operating point reaches to quasi-steady one. CFD results indicated similar tendency to experimental results on the variation of the pump operating point. Moreover, variation of the torque and axial thrust force during transient period also indicated deviation from each quasi-steady change. From the experimental and CFD results, the deviation of pump operating point, torque and axial thrust force from the quasi-steady change during pump startup period occurs at a large flow rate acceleration. The reason is thought to be due to that the flow field at large flow rate change cannot develop compared with that at the quasi-steady change.

Enhancing the Performance of Centrifugal Pump by Adding Cylindrical Disks at Inlet Suction

2019 ◽  
Author(s):  
Linda Sadik ◽  
Badih Jawad ◽  
Munther Y. Hermez ◽  
Liping Liu
Keyword(s):  
Numerical Simulation ◽  
Secondary Flow ◽  
Centrifugal Pump ◽  
Three Dimensional ◽  
Low Flow ◽  
Pump Efficiency ◽  
Centrifugal Pumps ◽  
Flow Rates ◽  
Pump Performance ◽  
Suction Performance

Abstract Optimizing the high efficiency design of centrifugal pumps requires a detailed understanding of the internal flow. The prediction of the flow inside the pump can be acquired by understanding the rotatory motion and the three-dimensional shape of the impellers, as well as its fundamental unsteady behavior. The flow inside a centrifugal pump is three-dimensional, unsettled and always associated with secondary flow structures. When a centrifugal pump operates under low flow rates, a secondary flow, known as recirculation, starts to begin. Inside this, the separation of flow increases, which creates vortices and cause local pressure to decrease, which induces cavitation. This phenomenon of recirculation will increase the Net Positive Suction Head Required (NPSHR). Improving the suction performance continues to remain a vital and continuous topic in the development and application of centrifugal pumps. In this research, the focal point is to enhance the pump suction performance under low flow rates by modifying the impeller design. This research entails a numerical simulation investigation on the addition of three different designs, each consisting of two cylindrical disks at the impeller inlet suction. It is hypothesized that these modifications will assist suppressing the recirculation phenomenon. The turbulent flow within the centrifugal pump was analyzed by applying the Reynolds-Averaged Navier-Stokes equations and the k–ϵ equations for turbulence modelling. The computational domain consists of the inlet, impeller, diffuser and outlet. Analysis of ΔP, torque data and pump efficiency was conducted. The application of CFD solvers to predict pump performance resulted in reduced prices for testing as well as pump development time. The numerical simulation concluded that placing 3-D multi-cylindrical disks at the impeller inlet section improved the centrifugal pump performance under low flow rates. The model design 1 resulted in a pump efficiency improvement of about 5% at low flow rates by lowering the amount of flow leaking back (re-circulation) through the internal suction.

Effect of Axial Clearance on the Efficiency of a Shrouded Centrifugal Pump

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Cao Lei ◽  
Zhang Yiyang ◽  
Wang Zhengwei ◽  
Xiao Yexiang ◽  
Liu Ruixiang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Axial Position ◽  
Hydraulic Efficiency ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
Axial Clearance

Clearance always exists between the rotating impeller shrouds and the stationary casing covers in shrouded centrifugal pumps, which affects the pump internal flow and performance. Model tests were conducted for a shrouded centrifugal pump with back blades on the front shroud, and the performance parameters were obtained for three different impeller axial positions. Adjusting the impeller axial position can change the axial size of both the front and back clearances simultaneously. The results show that a tiny variation of the axial clearance size can substantially change the pump performance. A large front clearance reduces the pump efficiency and head with little change in the shaft power. Numerical simulations for a wide range of operating conditions for the three models with different impeller axial positions using the Reynolds-Averaged Navier–Stokes (RANS) with shear stress transport (SST) k–ω turbulence model agree well with the experimental results. The numerical results show how the clearance flow interfere with the main flow as the axial clearance is varied. The change in the pump hydraulic efficiency, volumetric efficiency, and mechanical efficiency was analyzed for various clearances. The hydraulic efficiency is the lowest one of the three kinds of efficiency and changes dramatically as the flow rate increases; thus, the hydraulic efficiency plays a decisive role in the pump performance. The volumetric efficiency is most sensitive to the axial clearance, which obviously decreases as the front clearance is increased. Therefore, the volumetric efficiency is the key factor for the change of the gross efficiency as the axial clearance changes. The mechanical loss varies little with changes in both axial clearance and flow rate so the mechanical efficiency can be regarded as a constant. The effect of axial clearances on the efficiency of shrouded centrifugal pumps should be considered to enable more efficient designs.

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