scholarly journals Hydrodynamic Optimization for Design of a Submersible Axial-Flow Pump with a Swept Impeller

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3053
Author(s):  
Youn-Sung Kim ◽  
Man-Woong Heo ◽  
Hyeon-Seok Shim ◽  
Bong-Soo Lee ◽  
Dong-Hwan Kim ◽  
...  

Submersible pumps are now in high demand due to the sporadic occurrence of recent torrential rains. The current study was carried out to investigate the hydraulic characteristics of a submersible axial-flow pump with a swept impeller and to optimize the impeller and diffuser shapes of the pump to enhance the hydraulic performance. Three-dimensional Reynolds-averaged Navier–Stokes equations were solved with the shear stress transport turbulence model. The governing equations were discretized using the finite volume method, and unstructured tetrahedral and hexahedral meshes were used in the grid system. The optimal grid system was selected through a grid dependency test. A performance test for the submersible axial-flow pump was carried out experimentally, and the results of the numerical analysis were validated against the experimental results. The hydraulic efficiency and the total head were used as objective functions. For the first optimization, a multi-objective optimization was carried out to simultaneously improve the objective functions through a hybrid multi-objective evolutionary algorithm coupled with a response surface approximation by varying the swept angle and pitch angle of the blades of the rotating impeller. The second multi-objective optimization was performed using two design variables, i.e., the inlet angle and the length of the diffuser vanes, to simultaneously increase the objective functions. Clustered optimum designs in the Pareto optimal solutions yielded significant increases in the objective function values as compared with the reference design.

Author(s):  
Youn-Sung Kim ◽  
Hyeon-Seok Shim ◽  
Kwang-Yong Kim

This study aims to evaluate effects of blade pitch and inlet guide vane (IGV) angle on the performance characteristics of a submersible axial-flow pump. According to the results of the previous study, the efficiency at the design and over-load conditions were significantly affected by the angle of IGV due to change in the incidence angle. To investigate the interactional effects of IGV and blade angle are analyzed using three-dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model. The hexahedral grids are used in the computational domain and a grid-dependency test is performed to obtain an optimal number of the grids. In this study, combinations of three different blade angles and two different IGV angles are tested. Adjusting angle of IGV increases the total pressure of the pump with a blade pitch increase, which can increase the efficiency of the pump in operating range.


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.


Author(s):  
Yan Jin ◽  
Junxin Wu ◽  
Hongcheng Chen ◽  
Chao Liu

Diffuser vane of tubular pump is different with that of the axial flow pump, since the diffusion angle after the impeller is larger than as usual, which is an important part of bulb tubular pump system. By calculating the hydraulic loss of each part of bulb tubular pump system, it is found that the hydraulic loss of diffuser vane is in large proportion of the whole hydraulic loss. For this situation, focuses on the design parameters of diffuser vane such as diffuser vane length, unilateral edge diffusion angle, equivalent diffusion angle are necessary. In this paper, CFD method is used to simulate the turbulent flow in a bulb tubular pumping system with two different diffuser vanes. The three dimensional flow fields in the whole passage of pumping system with different diffuser vanes are obtained. The results show that all the main geometry parameters of the diffuser vane design affect the performances of tubular pumping system, it should be chosen the parameters reasonably based on the actual situation.


2012 ◽  
Vol 15 (4) ◽  
pp. 042026 ◽  
Author(s):  
R Kasahara ◽  
G Takano ◽  
T Murakami ◽  
T Kanemoto ◽  
K Komaki

Author(s):  
Youn-Sung Kim ◽  
Hyeon-Seok Shim ◽  
Kwang-Yong Kim

Abstract This paper presents a study of the effects of blade pitch angle and inlet guide vane (IGV) angle on the performance of a submersible axial-flow pump. To analyze the interaction effects between the IGVs and the rotor blades, both steady and unsteady three-dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model were solved. Hexahedral meshes were used in the computational domain and a grid-dependency test was performed to obtain an optimal number of grid nodes. The performance curves obtained by numerical simulation showed good agreement with experimental data. The results show that the fluctuation of hydraulic efficiency and head coefficient increased significantly under overload conditions as the IGV setting angle increased. Additionally, both the steady and unsteady performance characteristics were shown to be quite dependent on the combination of IGV angle and blade pitch angle, because the relative velocity at leading edge played an important role in the performance under overload conditions.


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