Numerical Investigations and Performance Experiments of a Deep-Well Centrifugal Pump With Different Diffusers

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
Ling Zhou ◽  
Weidong Shi ◽  
Weigang Lu ◽  
Bo Hu ◽  
Suqing Wu

In this paper, the design methodology of a new type of three-dimensional surface return diffuser (3DRD) is presented and described in detail. The main goal was to improve the hydrodynamic performance of the deep-well centrifugal pump (DCP). During this study, a two-stage DCP equipped with two different type diffusers was simulated employing the commercial computational fluid dynamics (CFD) software ANYSY-Fluent to solve the Navier-Stokes equations for three-dimensional steady flow. A sensitivity analysis of the numerical model was performed in order to impose appropriate parameters regarding grid elements number and turbulence model. The flow field and the static pressure distribution in the diffusers obtained by numerical simulation were analyzed, and the diffuser efficiency was defined to quantify the pressure conversion capability. The prototype experimental test results were acquired and compared with the data predicted from the numerical simulation, which showed that the performance of the pump with 3DRD is better than that of the traditional cylindrical return diffuser (CRD) under all operating conditions. The efficiency and single-stage head of the pump with 3DRD have been significantly improved compared with the standard DCP of the same class.

2011 ◽  
Vol 354-355 ◽  
pp. 659-663
Author(s):  
Wei Dong Shi ◽  
Ling Zhou ◽  
Wei Gang Lu ◽  
Hui Li

Choose the appropriate rear shroud diameter of impeller could get relatively small axial force and high pump performance. In this paper, a deep-well centrifugal pump impeller with a small rear shroud was studied by simulation and test. Two stages deep well centrifugal pump was simulated by means of a commercial CFD software that solved the Navier-Stokes equations for three-dimensional steady flow. The flow field and the static pressure distribution in the impellers obtained by steady numerical simulation were analyzed. By manufacturing and testing, the test results was acquired, and then compared with the predicting data of the numerical simulation. Results show that trimming the rear shroud could reduce the axial force, but too small rear shroud diameter lead to pump performance decline.


2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Ling Zhou ◽  
Weidong Shi ◽  
Wei Li ◽  
Ramesh Agarwal

A multistage deep-well centrifugal pump (DCP) with different impeller rear shroud radius have been investigated both numerically and experimentally under multiconditons, which aims at studying the influence of impeller rear shroud radius to the axial force and pump hydraulic performance. During this study, a two-stage DCP equipped with three different impellers was simulated employing the commercial computational fluid dynamics (CFD) software ANYSY-Fluent to solve the Navier-Stokes equations for three-dimensional steady flow. High-quality structured grids were meshed on the whole computational domain. Test results were acquired by prototype experiments, and then compared with the predicted pump performance and axial force. The static pressure distribution in the pump passage obtained by numerical simulation was analyzed. The results indicated that the appropriate impeller rear shroud radius could improve the pump performance and lower the axial force significantly.


2013 ◽  
Vol 694-697 ◽  
pp. 56-60
Author(s):  
Yue Jun Ma ◽  
Ji Tao Zhao ◽  
Yu Min Yang

In the paper, on the basis of three-dimensional Reynolds-averaged Navier-Stokes equations and the RNG κ-ε turbulence model, adopting Three-dimensional unstructured grid and pressure connection the implicit correction SIMPLEC algorithm, and using MRF model which is supported by Fluent, this paper carries out numerical simulation of the internal flow of the centrifugal pump in different operation points. According to the results of numerical simulation, this paper analyzes the bad flow phenomena of the centrifugal pump, and puts forward suggests about configuration perfected of the centrifugal pump. In addition, this paper is also predicted the experimental value of the centrifugal pump performance, which is corresponding well with the measured value.


10.29007/lbz2 ◽  
2018 ◽  
Author(s):  
Vijaypratap R. Singh ◽  
Mahesh J. Zinzuvadia ◽  
Saurin Sheth ◽  
Ruchir J. Desai

To improve the hydrodynamic performance of the centrifugal pump, in present work a DOE technique Taguchi L9 orthogonal array experiment was carried out to optimize the impeller design parameters. The Navier-Stokes equations for three-dimensional steady flow is solved by computational fluid dynamics (CFD) code. The experimental test result of the original pump was compared with the data predicted from the numerical simulation. The comparison shows the closeness of predicted values with the experimental values, leads to validation of the numerical model under the specific range of operating conditions. Four geometric parameters of impeller were chosen as the variable factors viz. Number of blade, Impeller blade outlet angle, Impeller blade Inlet angle and Impeller blade wrapping angle. According to L9 orthogonal array, nine impellers were modelled using CAD modelling software and CFD analysis is carried out using ANSYS CFX. The impellers were equipped with the same volute during all the simulations. The modelled impellers were simulated by the same numerical method, which has been validated. The best parametric combination for higher efficiency is analysed finally. Results show the improvement of 4.25% higher efficiency compared with the original pump. The geometry selected for this model may be the best one to get the maximum efficiency for such pumps.


Author(s):  
Yan Jin ◽  
Chao Liu ◽  
Li Cheng

Research on three-dimensional flow field in a tubular pumping system using numerical simulation based on the Reynolds time-averaged Navier-Stokes equations and the RNG k–ε turbulent model. By using this method, the performance of pumping system such as head, shaft power and efficiency are predicted based on the calculation of different operating conditions in the discharge range from 20L/s to 35L/s at the same rotating speed. For verifying the accuracy and reliability of the calculation results, a tubular pumping system bedstand is designed for the permarmance test. The comparison of simulation results and the experiment data shown that the calculation performances close agreement with the experiment results in the high efficiency area, but in the condition of large discharge and low discharge, deviations were existed between the two results. Combining with the results of numerical simulation and experiment, which can provide more evidences for the hydraulic performances prediction and optimization design of pumping system.


2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Zheng-Chuan Zhang ◽  
Hong-Xun Chen ◽  
Zheng Ma ◽  
Jian-Wu He ◽  
Hui Liu ◽  
...  

Through numerical simulation and experiments analysis, it is indicated that the hydraulic and anticavitation performance of a centrifugal pump with twisted gap drainage blades based on flow control theory can be significantly improved under certain operating conditions. In order to introduce the technology of gap drainage to practical applications, we put forward the parameter formulas of the twisted gap drainage blade to design three-dimensional new type blade, which are also proved to be effective for enhancing the dynamic characteristics of the centrifugal pump. Furthermore, a practical centrifugal pump is redesigned to be a twisted gap drainage impeller with the same structure size as the original impeller, and the nonlinear hybrid Reynolds-averaged Navier–Stokes (RANS)/large eddy simulation (LES) method is employed to simulate the hydraulic dynamic characteristics. Numerical simulation results show that the hydraulic performance and dynamic characteristics of the redesigned impeller centrifugal pump are significantly enhanced. In experiments, the twisted gap drainage blades structure not only remarkably improves the hydraulic performance and the pressure pulsation characteristics of the centrifugal pump but also reduces the vibration intensity.


2013 ◽  
Vol 319 ◽  
pp. 599-604
Author(s):  
Makhsuda Juraeva ◽  
Kyung Jin Ryu ◽  
Sang Hyun Jeong ◽  
Dong Joo Song

A computational model of existing Seoul subway tunnelwas analyzed in this research. The computational model was comprised of one natural ventilationshaft, two mechanical ventilationshafts, one mechanical airsupply, a twin-track tunnel, and a train. Understanding the flow pattern of the train-induced airflow in the tunnel was necessary to improve ventilation performance. The research objective wasto improve the air quality in the tunnel by investigating train-induced airflow in the twin-track subway tunnel numerically. The numerical analysis characterized the aerodynamic behavior and performance of the ventilation system by solving three-dimensional turbulent Reynolds-averaged Navier-Stokes equations. ANSYS CFX software was used for the computations. The ventilation and aerodynamic characteristics in the tunnel were investigated by analyzing the mass flowrateat the exits of the ventilation mechanicalshafts. As the train passed the mechanical ventilation shafts, the amount of discharged-air in the ventilationshafts decreased rapidly. The air at the exits of the ventilation shafts was gradually recovered with time, after the train passed the ventilation shafts. The developed mechanical air-supply for discharging dusty air and supplying clean airwas investigated.The computational results showed that the developed mechanical air-supplycould improve the air quality in the tunnel.


Author(s):  
K M Guleren ◽  
A Pinarbasi

The main goal of the present work is to analyse the numerical simulation of a centrifugal pump by solving Navier-Stokes equations, coupled with the ‘standard k-∊’ turbulence model. The pump consists of an impeller having five curved blades with nine diffuser vanes. The shaft rotates at 890r/min. Flow characteristics are assumed to be stalled in the appropriate region of flowrate levels of 1.31-2.861/s. Numerical analysis techniques are performed on a commercial FLUENT package program assuming steady, incompressible flow conditions with decreasing flowrate. Under stall conditions the flow in the diffuser passage alternates between outward jetting when the low-pass-filtered pressure is high to a reverse flow when the filtered pressure is low. Being below design conditions, there is a consistent high-speed leakage flow in the gap between the impeller and the diffuser from the exit side of the diffuser to the beginning of the volute. Separation of this leakage flow from the diffuser vane causes the onset of stall. As the flowrate decreases both the magnitude of the leakage within the vaneless part of the pump and reverse flow within a stalled diffuser passage increase. As this occurs, the stall-cell size extends from one to two diffuser passages. Comparisons are made with experimental data and show good agreement.


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