Exit Blade Angle and Roughness Effect on Centrifugal Pump Performance

Author(s):  
Sayed Ahmed Imran Bellary ◽  
Abdus Samad

Exit blade angle and impeller surface roughness has a significant effect on the performance of a centrifugal pump impeller handling different viscosity fluids. In this paper, a three-dimensional flow simulation using Reynolds averaged Navier Stokes (RANS) equations for the performance analysis of the impeller is reported. The analysis using water and viscous liquids has been accomplished for different flow conditions, exit blade angle and roughness values. Standard k-ε two equation model is used for the turbulent closure of steady incompressible flow. The investigation shows that the blade exit angle has influence on the head, shaft power and efficiency of the impeller for different liquids. Rise in head, increase in shaft power and decrease in hydraulic efficiency have been observed with increasing roughness.

2007 ◽  
Vol 2007 ◽  
pp. 1-8 ◽  
Author(s):  
K. W. Cheah ◽  
T. S. Lee ◽  
S. H. Winoto ◽  
Z. M. Zhao

The current investigation is aimed to simulate the complex internal flow in a centrifugal pump impeller with six twisted blades by using a three-dimensional Navier-Stokes code with a standardk-εtwo-equation turbulence model. Different flow rates were specified at inlet boundary to predict the characteristics of the pump. A detailed analysis of the results at design load,Qdesign, and off-design conditions, Q = 0.43Qdesignand Q = 1.45Qdesign, is presented. From the numerical simulation, it shows that the impeller passage flow at design point is quite smooth and follows the curvature of the blade. However, flow separation is observed at the leading edge due to nontangential inflow condition. The flow pattern changed significantly inside the volute as well, with double vortical flow structures formed at cutwater and slowly evolved into a single vortical structure at the volute diffuser. For the pressure distribution, the pressure increases gradually along streamwise direction in the impeller passages. When the centrifugal pump is operating under off-design flow rate condition, unsteady flow developed in the impeller passage and the volute casing.


2011 ◽  
Vol 317-319 ◽  
pp. 789-793
Author(s):  
Xiao Feng Shang ◽  
Liang Tong ◽  
Zhi Jian Wang

The three-Dimensional model of 40BZ6-15 centrifugal pump is built by the Solidworks software. This paper employs three-D Navier-Stokes equation and standard equation, and uses MRF and STMPLE algorithm to simulate the internal flowing of the 40BZ6 centrifugal pump. The velocity field and pressure field are gained. Through a further analysis, the rule of the internal flow of the centrifugal pump is unveiled, and then the simulative results are compared with the experimental ones, which can provide the base for the further improvement of the centrifugal pump.


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.


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):  
Akira Goto

The complex three-dimensional flow fields in a mixed-flow pump impeller are investigated by applying the incompressible version of the Dawes’ 3D Navier-Stokes code. The applicability of the code is confirmed by comparison of computations with a variety of experimentally measured jet-wake flow patterns and overall performances at four different tip clearances including the shrouded case. Based on the computations, the interaction mechanism of secondary flows and the formation of jet-wake flow are discussed. In the case of large tip clearances, the reverse flow caused by tip leakage flow is considered to be the reason for the thickening of the casing boundary layer followed by the deterioration of the whole flow field.


Author(s):  
Munther Y. Hermez ◽  
Badih A. Jawad ◽  
Liping Liu ◽  
Vernon Fernandez ◽  
Kingman Yee ◽  
...  

The present work aims to numerically study the inlet flow recirculation and modified impeller interaction in a centrifugal pump. An optimization of modified shrouded impeller with curved disk arrangement to suppress the unsteady flow recirculation is pursued. This modification will enhance the impeller characteristics with a wider operation range at both low and high flow rates in a high speed centrifugal pump type. The unstable flow in the centrifugal pumps is a common problem that leads to damage in the pump’s internal parts, consequently increases the operating cost. At certain flow rates, generally below the Best Efficiency Point (BEP), all centrifugal pumps are subject to internal recirculation occurs at the suction and discharge areas of the impeller. For decades, experimental work has been done to investigate the complex three-dimensional flow within centrifugal pumps impellers, before computational work gains momentum due to advancement of computing power and improved numerical codes. In this study the impeller with a curved disk arrangement has been investigated by using a three-dimensional Navier-Stokes code with a standard k-ε turbulence model. The purpose is to evaluate and select the optimum impeller modification that would increase the pump suction flow rate range. Three-dimensional numerical Computational Fluid Dynamics (CFD) tools are used to simulate flow field characteristics inside the centrifugal pump and provide critical hydraulic design information. In the present work, ANSYS v.16.1 Fluent solver is used to analyze the pressure and velocity distributions inside impeller suction and discharge passages. The ultimate goal of this study is to manufacture and validate the most optimized and efficient centrifugal pump impeller with a curved disk. The best case curve identifies the highest increase of total pressure difference by 22.1%, and highest efficiency by 92.3% at low flowrates.


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.


1996 ◽  
Vol 118 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Chuichi Arakawa ◽  
Yi Qian ◽  
Takashi Kubota

A three-dimensional Navier-Stokes code with pseudo-compressibility, an implicit formulation of finite difference, and a k – ε two-equation turbulence model has been developed for the Francis hydraulic runner. The viscous flow in the rotating field can be simulated well in the design flow operating condition as well as in the off-design conditions in which a strong vortex occurs due to the separation near the leading edge. Because the code employs an implicit algorithm and a wall function near the wall, it does not require a large CPU time. It can therefore be used on a small computer such as the desk-top workstation, and is available for use as a design tool. The same kind of algorithm that is used for compressible flows has been found to be appropriate for the simulation of complex incompressible flows in the field of turbomachinery.


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