Strength Analysis of Axial-Flow Pump Impeller Based on FSI

2015 ◽  
Vol 799-800 ◽  
pp. 581-584
Author(s):  
Xin Zhang ◽  
Yuan Zheng ◽  
Zheng Yang Zhang ◽  
Jun Qian ◽  
Jie Fu ◽  
...  

It’s necessary to calculate and analyze the strength of the pump impeller for the safe operation of the pump. In this paper, the impeller strength of a two-way full-adjust horizontal axial-flow pump in a domestic pump station under forward pumping conditions was calculated by using the unidirectional fluid-structure interaction method; it means loading the blade surface water pressure calculating from CFD software CFX as structure surface loads to the blade, and then calculating the strength of the impeller using finite element software ANSYS ; the strength of the impeller was calculated under different blade rotating angle conditions. Through the calculation, we has got static stress and deformation distribution in the impeller. The results show that under each blade rotating angle, the maximum static stress always increases with lift increasing; the maximum static stress occurs at the junction of the blade and hub; the stress concentration also occurs in there prone to cause fatigue failure; maximum deformation of the blade occurs in the leading edge close to the rim; the maximum static stress is far less than yield strength of the material that the static stress can not cause cracks.

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaohui Duan ◽  
Fangpin Tang ◽  
Hao Xu ◽  
Jian Chen ◽  
Qun Lu ◽  
...  

The hydraulic excitation characteristics of axial flow pump unit are studied through theoretical analysis, numerical simulation and field test in this paper. The correlation between impeller hydraulic and radial vibration displacement of impeller centroid is obtained through theoretical analysis. Through the 1-way fluid-solid-interaction (FSI) numerical simulation, the distributions of water pressure and displacement on the impeller surface are obtained, and the time-domain and frequency-domain characteristics of transient hydraulic and radial displacement are revealed. Through the field test, the external characteristics of axial flow pump unit and the time-frequency characteristics of the pressure pulsation at the measuring points beside the inlet of the impeller are obtained. The comparisons between simulation results and experimental results show that the former is accurate and reliable.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1653
Author(s):  
Nengqi Kan ◽  
Zongku Liu ◽  
Guangtai Shi ◽  
Xiaobing Liu

To reveal the effect of tip clearance on the flow behaviors and pressurization performance of a helico-axial flow pump, the standard k-ε turbulence model is employed to simulate the flow characteristics in the self-developed helico-axial flow pump. The pressure, streamlines and turbulent kinetic energy in a helico-axial flow pump are analyzed. Results show that the tip leakage flow (TLF) forms a tip-separation vortex (TSV) when it enters the tip clearance and forms a tip-leakage vortex (TLV) when it leaves the tip clearance. As the blade tip clearance increases, the TLV moves along the blade from the leading edge (LE) to trailing edge (TE). At the same time, the entrainment between the TLV and the main flow deteriorates the flow pattern in the pump and causes great hydraulic loss. In addition, the existence of tip clearance also increases the possibility of TLV cavitation and has a great effect on the pressurization performance of the helico-axial flow pump. The research results provide the theoretical basis for the structural optimization design of the helico-axial flow pump.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1493
Author(s):  
Weidong Cao ◽  
Wei Li

The operating range of axial flow pumps is often constrained by the onset of rotating stall. An improved method using a double inlet nozzle to stabilize the performance curve is presented in the current study; a single inlet nozzle and three kinds of double inlet nozzle with different rib gap widths at the inlet of axial flow pump impeller were designed. Three dimensional (3D) incompressible flow fields were simulated, and the distributions of turbulence kinetic energy and velocity at different flow rates located at the inlet section, as well as the pressure and streamline in the impeller, were obtained at the same time. The single inlet nozzle scheme and a double inlet nozzle scheme were studied; the experimental and numerical performance results show that although the cross section is partly blocked in the double inlet nozzle, the head and efficiency do not decline at stable operation flow rate. On small flow rate condition, the double inlet nozzle scheme effectively stabilized the head-flow performance, whereby the block induced by the backflow before the impeller was markedly improved by using a double inlet nozzle. It has also been found that the rib gap width impacts the efficiency curve of the axial flow pump.


1983 ◽  
Vol 105 (3) ◽  
pp. 277-283 ◽  
Author(s):  
M. Murakami ◽  
K. Minemura

Motion of air bubbles in a high-specific-speed axial-flow pump impeller was analyzed on the basis of measured streak lines of air bubbles in the impeller. The results were compared with those obtained by a numerical solution of the bubble motion equations for three dimensional flow. Governing factors of the bubble motion are the drag force due to the surrounding water and the force due to the pressure gradient. Trajectories of the bubbles deviate somewhat from the streamlines of water, and the amount of the deviation is dependent on the bubble diameter and also on specific-speeds of the pumps and flow rate of water.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Honggeng Zhu ◽  
Ge Bo ◽  
Yuanbing Zhou ◽  
Rentian Zhang ◽  
Jilin Cheng

Axial-flow pumps are widely used in every sector of China. After many years of operation, the aging of mechanical and electrical facilities poses threats to their steady and safe operation. Taking the technical innovation of an axial-flow pump station as an example, the study is focused on the pump selection and performance prediction. The pump similarity law and specific speed were applied to guide the pump selection based on the designed head and discharge. The performances of pump models were compared and it is suggested for the technical innovation that when the selected model pump is adopted, the impeller diameter is kept at 3100 mm and the rotational speed is reduced from 150r/min to 136.4r/min to improve its cavitation performance. A three-dimensional pumping system model was established by using software Pro/E and CFD analyses were conducted to predict the hydraulic performance of the pumping system for the evaluation of technical innovation. It is shown through the comparison of computed results with model test results that the designed flow rate corresponding to the designed head can be fully satisfied with the selected pump and stronger pumping capacity can be prospected at the designed and mean lifting head. The pumping system model tests, in comparison between the original and the selected model pump, indicate that when the innovated pump station operates under characteristic heads, the pumping system efficiency can be raised by more than 3 percentages, and the cavitation allowance can be decreased by 0.90m; thus, better engineering and economic benefits can be prospected through the technical innovation.


2015 ◽  
Vol 741 ◽  
pp. 481-485
Author(s):  
Hong Ming Zhang ◽  
Li Xiang Zhang

The paper presents numerical simulation of the vortex in a submersible axial flow pump impeller using OpenFoam code. A mixture assumption and a finite rate mass transfer model were introduced to analyze vortex. The finite volume method is used to solve the governing equations of the mixture model and the pressure-velocity coupling is handled via a Pressure Implicit with Splitting of Operators (PISO) procedure. Simulation results have shown that the cavitation may occur on the lower portion of impeller suction side. And the blade channel vortex will be formed in the impeller. It can induce the pressure pulsation in the impeller and can result in reduced efficiency of the submersible axial flow pump.


2008 ◽  
Vol 130 (7) ◽  
Author(s):  
Wen-Guang Li

The two-step method for optimizing net positive suction head required (NPSHr) of axial-flow pumps is proposed in this paper. First, the NPSHr at the impeller tip is optimized with impeller diameter based on experimental data of 2D cascades in available wind tunnels. Then, it is optimized again with the velocity moment at the impeller outlet, which is expressed in terms of two parameters. The blade geometry is generated and flow details are clarified by using the radial equilibrium equation, actuator disk theory, and 2D vortex element method in the optimizing process. The NPSHr response surface has been established in terms of these two parameters. The results illustrate that the second optimization allows NPSHr to be reduced by 37.5% compared to the first optimization. Therefore, this two-step method is effective and expects to be applied in the axial-flow pump impeller blade design. The simulations of 3D turbulent flow with various cavitation models and related confirming experiments are going to be done in the axial-flow impellers designed with this method.


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