Experimental Performance Evaluation of a Centrifugal Pump With Different Impeller Vane Geometries

Author(s):  
Susanta K. Das

Centrifugal pumps vane geometry plays an important role in pump’s overall performance. Thus, to know the impeller vane geometry effects on the performance of a centrifugal pump are essential from pump’s design point of view. In this study, an experimental investigation is carried out to judge the impeller vane geometry effects on the performance of a centrifugal pump. The performance of three different impeller vane geometries is evaluated in this investigation. To acquire pump performance and characteristics curves, inlet and outlet valves were manually adjusted and the pump’s rpm were varied remotely through computer control. The pressure data were obtained via installed flow rotameter for different flow rates with constant pump speed – 1800 rpm. Experimental data were used to calculate different physical parameters, such as the pump head, water horsepower — the power added to the fluid, power input to the pump–brake horse power, and pump efficiency for each of impeller vane geometries. The pump’s performance curves and the system curves were then plotted for each of the vane geometries. The results show that the pump performance as well as efficiency varies significantly for each of the impeller vane geometries. The results help to understand how to determine appropriate operating conditions and design parameters for different impeller vane geometries for obtaining optimized pump performance.

Author(s):  
Jiangfeng Fu ◽  
Huacong Li ◽  
Ding Fan ◽  
Wenbo Shen ◽  
Xianwei Liu

This paper was presented a method of integrated loss model by considering all kinds of loss type in centrifugal pumps. The geometric structure and loss mechanism of the flow parts in the centrifugal pump were analyzed, such as suction chamber, impeller, vaneless diffuser chamber, volute type water collecting chamber and outlet diffusion section. The hydraulic loss model, volume loss model, friction loss and mechanical loss model of centrifugal pump were established respectively by combining the flow theory. Finally, an integrated loss model of centrifugal pump was constructed, which can establish the relationship between the 12 main design parameters and pump efficiency of the centrifugal pump. Then the performance prediction of an aeroengine fuel centrifugal pump was carried out based on the loss model, and the loss model predictions were compared with the experimental data and CFD simulation performance prediction data. Simulation results show that:The efficiency predicted value relative error of centrifugal pump is less than 2.8% between the loss model and the experimental data. The computational efficiency of CFD is less than 4.4% compared with the experimental data in the design condition. The relative error is about 1.6% between the CFD method and the loss model which shows that the loss model predicts efficiency accuracy is better than the CFD method. It shows that this method can be used to predict the efficiency performance of centrifugal pump under design process.


Author(s):  
Yun Xu ◽  
Lei Tan ◽  
Shuliang Cao ◽  
Wanshi Qu

Optimization design of centrifugal pumps involving multiple parameters and objectives is a complicated research topic. The orthogonal method is introduced in the present study to find a high efficiency and low cost way in the optimization process of a centrifugal pump. A orthogonal table designation L16(45) is established, in which 16 individuals of impellers are generated with five design parameters: blade wrap angle, blade angles at impeller inlet and outlet, blade leading edge position, and blade trailing edge lean varying at four levels for each parameter. To realize the multiobjective optimization of both pump efficiency and cavitation performance, an integrated factor considering the weight of two objectives is introduced. On the basis of validated computational fluid dynamics (CFD) technique, the range analysis gives the influence order of five parameters and also determines the value of each parameter. Finally, the optimal centrifugal pump is obtained with remarkable superiority on the efficiency of 3.09% rise and cavitation performance of 1.45 m promotion in comparison with the original pump.


2018 ◽  
Vol 20 (2) ◽  
pp. 29-35
Author(s):  
Adam Hafizar Pohan

This study was conducted to identify the performance of centrifugal pump series configuration and parallel configuration experimentally and Ansys simulation. In the previous study, the performance of centrifugal pumps was calculated by varying the valve opening. In this study researchers varied motor rotation of 1000 rpm, 1200 rpm, 1400 rpm, 1600 rpm and 1800 rpm with open valve 100%. The results show that series configuration has higher head value than parallel configuration. While the parallel configuration has a higher capacity value than the series configuration. The highest pump efficiency for this pump performance test is in series configuration of 1800 rpm is 83.4% for experimental and 85% for simulation. While the lowest pump efficiency is in parallel configuration pumps of 1800 rpm with an efficiency 14.1% for experimental and 15.5% for simulation.


Author(s):  
Linda Sadik ◽  
Badih Jawad ◽  
Munther Y. Hermez ◽  
Liping Liu

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.


2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Cao Lei ◽  
Zhang Yiyang ◽  
Wang Zhengwei ◽  
Xiao Yexiang ◽  
Liu Ruixiang

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.


Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 60
Author(s):  
Khaled Alawadhi ◽  
Bashar Alzuwayer ◽  
Tareq Ali Mohammad ◽  
Mohammad H. Buhemdi

Since centrifugal pumps consume a mammoth amount of energy in various industrial applications, their design and optimization are highly relevant to saving maximum energy and increasing the system’s efficiency. In the current investigation, a centrifugal pump has been designed and optimized. The study has been carried out for the specific application of transportation of slurry at a flow rate of 120 m3/hr to a head of 20 m. For the optimization process, a multi-objective genetic algorithm (MOGA) and response surface methodology (RSM) have been employed. The process is based on the mean line design of the pump. It utilizes six geometric parameters as design variables, i.e., number of vanes, inlet beta shroud, exit beta shroud, hub inlet blade draft, Rake angle, and the impeller’s rotational speed. The objective functions employed are pump power, hydraulic efficiency, volumetric efficiency, and pump efficiency. In this reference, five different software packages, i.e., ANSYS Vista, ANSYS DesignModeler, response surface optimization software, and ANSYS CFX, were coupled to achieve the optimized design of the pump geometry. Characteristic maps were generated using simulations conducted for 45 points. Additionally, erosion rate was predicted using 3-D numerical simulations under various conditions. Finally, the transient behavior of the pump, being the highlight of the study, was evaluated. Results suggest that the maximum fluctuation in the local pressure and stresses on the cases correspond to a phase angle of 0°–30° of the casing that in turn corresponds to the maximum erosion rates in the region.


Author(s):  
Lozica Ivanović ◽  
Miloš Matejić

Gerotor pumps are well known by a compact design, simple structure and low noise level, which makes them suitable for use in the automotive industry, and especially in hydraulic systems for engine lubrication. One of the main disadvantages of gerotor pumps is the inability to adjust to wear, which significantly reduces the pump efficiency. In order to mitigate the negative effect of the inevitable wear process, this paper presents a methodology for determining the optimal combination of trochoid gears design parameters for a defined aspect. An appropriate mathematical model has been developed to analyze the effect of changes in gear design parameters in relation to maximum contact stresses, pressure changes in gerotor pump chambers and wear rate proportional factor (WRPF). Verification of the developed models was performed by realizing physical pairs of gears and laboratory experiments with simulation of pump operating conditions. The results and conclusions presented in this paper, with an emphasis on the actual work processes, bring very important perspectives for the gerotor pumps design with improved performance.


Author(s):  
M. H. Shojaee Fard ◽  
M. B. Ehghaghi ◽  
F. A. Boyaghchi

On the test bed of centrifugal pump, the centrifugal pump performance has been investigated using water and viscous oil as Newtonian fluids, whose kinematic viscosities are 1 × 10−6, 43 × 10−6 and 62 × 10−6 m2/s, respectively. Also, the finite volume method is used to model the three dimensional viscous fluids for different operating conditions. For these numerical simulations the SIMPLEC algorithm is used for solving governing equations of incompressible viscous/turbulent flows through the pump. The κ-ε turbulence model is adopted to describe the turbulent flow process. These simulations have been made with a steady calculation and using the multiple reference frame (MRF) technique to take into account the impeller-volute interaction. Numerical results are compared with the experimental characteristic curve for each viscous fluid. The data obtained allow the analysis of the main phenomena existent in this pump, such as: head, efficiency, power and pressure field changes for different operating conditions. Also, the correction factors for oils are obtained from the experimental for part loading (PL), best efficiency point (BEP) and over loading (OL) and the results are compared with proposed factors by American Hydraulic Institute (HIS) and Soviet Union (USSR). The comparisons between the numerical and experimental results show a good agreement.


2021 ◽  
Vol 5 (1) ◽  
pp. 80-88
Author(s):  
Nur Hanna Khairul Anuar ◽  
Mohd Nizar Mhd Razali ◽  
Mohamad Rusydi Mohamad Yasin ◽  
Musfirah Abdul Hadi ◽  
Abdul Nasir Abd. Ghaffar

Viscosity is one of the factors affecting the performance of the centrifugal pump. A centrifugal pump is a device that used driven motor called impeller to move fluid by rotational energy. This thesis is about the analysis of the performance of the centrifugal pump when transferring viscous liquids. For this project, the objective is to design and fabricate a device that can pump liquid with various viscosity using centrifugal pump. The liquids used in the experiment are comprised of a mixture of detergent and water with different ratio to alter the viscosity. The viscosity is being identified by the usage of Zahn Cup Method with the temperature kept constant at 26 °C throughout the experiment. The performance of the centrifugal pump is being investigated by four parameters which is the flowrate, Total Dynamic Head (TDH), power and efficiency. The performance of the centrifugal pump can be accessed by altering the pump shaft speed in order to get various reading for the flow rate. In order to alter the pump shaft speed, the usage of motor with Variable Frequency Drive (VFD) is implemented. The values for the flowrate and pump shaft power are measured by flowmeter and Variable Frequency Drive (VFD). The Total Dynamic Head (TDH), hydraulic power and pump efficiency is calculated based on the reading of the flowmeter and pump shaft power displayed at Variable Frequency Drive (VFD). At the end of this project, the pump performance while pumping different viscous liquids at different flowrates is being identified.


Author(s):  
Shouqi Yuan ◽  
Jinfeng Zhang ◽  
Yue Tang ◽  
Jianping Yuan ◽  
Yuedeng Fu

The research on a centrifugal pump of low specific speed with splitter blades was carried out in recent years by our group, is systematically introduced in this paper. The design method is summarized also. At the beginning, based on the former L9(34) orthogonal test, Particle Imagine Velocity (PIV) tests and Computational Fluid Dynamics (CFD) simulations were carried out for several designs with different splitter blade length. Results show that for an impeller with splitter blades the “jet-wake” flow at the impeller outlet is improved, and the velocity distribution inside the impeller is more uniform. This explains that the impeller with splitter blades shows higher performance (especially in head and efficiency). Meanwhile, the numerical simulation results were compared with the test results, which confirm that, CFD technology can be used to observe inner flow distribution and forecast pump performance tendency. Later, a further L9(34) orthogonal test, which adopt the blade number as a new variable, was designed to explore the relationship between geometry parameters of splitter blade and pump performance, and corresponding CFD simulations for the flow field with volute were also done. From the test results the influence of the main design parameters on the hydraulic performance of a centrifugal pump and its reasonable value range are determined. The simulations forecasted pump performance show good consistency with that from tests at the rated point, and the simulated error at other flow rates were analyzed. Thirdly, in order to save research cost, numerical simulations were done for the full flow field including the cavity inside the volute and impeller. By analyzing the distribution law of blade torque and turbulent kinetic energy in the impeller, the value fetching principle for the splitter blade inlet diameter is presented as “the splitter blades torque should be positive”, and by analyzing the distribution of blades loading, the flow distribution rules and pump performance influenced by different splitter blades off-setting angles and inlet diameters were discovered. The disk friction loss, which consuming much energy in centrifugal pumps, was also forecasted at various operating conditions. The results were compared with that from empirical formulas, which show great accordance at the rated point, and the forecasted results at off-design points were analyzed also. Finally, the research results and the design method for the centrifugal pump with splitter blades, such as how to select splitter blade number, the off-setting angle, the inlet diameter and the deflection angle, were summarized.


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