Multi-condition design optimization of groove flow control technique in an axial-flow pump

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinghong Li ◽  
Rui Zhang ◽  
Hui Xu ◽  
Jiangang Feng
Keyword(s):  
Flow Control ◽  
Design Optimization ◽  
Prediction Models ◽  
Optimization Problems ◽  
Axial Flow ◽  
Combination Method ◽  
Control Technique ◽  
Condition Optimization ◽  
Axial Flow Pump ◽  
Flow Pump

Abstract To address the limitations of conventional groove designs in groove flow control technique, this paper optimizes the groove flow control technique for an axial-flow pump combining the design of experiment (DOE), response surface methodology (RSM), and particle swarm optimization (PSO). The sample space is designed using a combination method (OD-LHS) of orthogonal design (OD) and Latin hypercube sampling (LHS). Performance prediction models for the axial-flow pump are established using RSM. Taking the multi-condition comprehensive evaluation function as the final optimization objective, PSO is used to find the optimum groove parameters. The results show that the proposed method is effective in solving multi-condition optimization problems for grooves in axial-flow pumps. The optimal groove length, depth, and distance from the center of the impeller are 0.8, 0.05, and 0.2 times the impeller diameter, respectively, and the number is three times the number of blades. In addition, the optimal grooves effectively improve the hydraulic performance of the axial-flow pump under stall conditions. This study sheds light on the design optimization of the groove flow control technique for axial-flow pumps and other types of hydraulic machinery.

Improving the Performance of an Axial Flow Pump: An Overview

2021 ◽  
Vol 107 ◽  
pp. 15-25
Author(s):  
M. Prince Moifatswane ◽  
Nkosinathi Madushele ◽  
Noor A. Ahmed
Keyword(s):  
Design Optimization ◽  
Axial Flow ◽  
Optimization Methods ◽  
Hydraulic Performance ◽  
Low Flow ◽  
Flow Conditions ◽  
Pump Performance ◽  
Operational Conditions ◽  
Axial Flow Pump ◽  
Flow Pump

Thus far, axial flow pumps remain a significant hydrodynamic unit. These pumps have common applications for various systems that require a high flow rate and a lower head. They tend to be less efficient and consume excessive power when operating at low flow conditions. Most of the studies focus on improving the hydraulic performance of these pumps based on the best efficiency point (BEP) flow conditions. This approach is mostly based on the assumption that the pump will always operate at BEP. However, this is not always the case, because the operational condition of the pump may require an adjustment to meet certain system demands. Hence, it is necessary to emphasize the need to improve the hydraulic performance of these pumps for multiple flow conditions. This means that in addition to BEP, the lowest, and the highest operational conditions need to be considered when improving the pump performance. Also, it is important to review the phenomenon of cavitation in every design optimization investigation, given its significance to pump performance and some misrepresentation which are sometimes associated with its assessment. Therefore. the main contribution of this article is to briefly discuss the successful and unsuccessful design optimization methods of an axial flow pump. Furthermore, it highlights the significance of improving the pump performance at multiple flow conditions and also to incorporate the analysis of using CFD methods to analyze the results of cavitation performance in every pump performance improvement investigation.

scholarly journals Investigation into the Influence of Division Pier on the Internal Flow and Pulsation in the Outlet Conduit of an Axial-Flow Pump

2021 ◽  
Vol 11 (15) ◽  
pp. 6774
Author(s):  
Fan Yang ◽  
Dongjin Jiang ◽  
Tieli Wang ◽  
Pengcheng Chang ◽  
Chao Liu ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Pressure Pulsation ◽  
Axial Flow ◽  
Hydraulic Loss ◽  
Main Frequency ◽  
Starting Position ◽  
The Difference ◽  
Axial Flow Pump ◽  
Outlet Conduit ◽  
Flow Pump

The outlet conduit is an important construction connecting the outlet of the pump guide vane and the outlet pool; in order to study the hydraulic performance of the straight outlet conduit of the axial-flow pump device, this paper adopts the method of numerical simulation and analyzes the influence of the division pier on the pressure and velocity distribution inside and near the wall of the straight outlet conduit based on three design schemes. Four pressure pulsation measuring points were arranged in the straight outlet conduit, and the low-frequency pulsation characteristic information inside the straight outlet conduit with and without the division pier was extracted by wavelet packet reconstruction. The results show that the addition of a division pier has an effect on the hydraulic loss, near-wall pressure and velocity distribution in the straight outlet conduit. A small high-pressure zone is formed near the wall at the starting position of the division pier, and a large high-speed zone is formed on the left side at the starting position of the division pier. The length of the division pier has no significant effect on the flow distribution of the straight outlet conduit and the pressure and velocity distribution near the wall. Under different working conditions, each monitoring point has the maximum energy in the sub-band (0~31.25 Hz). With the increase of the flow rate, the total pressure energy of the straight outlet conduit decreases gradually. Under each condition, the difference of the energy proportion of the horizontal monitoring points of the straight outlet conduit is small, and the difference of the energy proportion of the two monitoring points at the top and bottom of the outlet channel is relatively large. The energy of the two monitoring points in the straight outlet conduit with a division pier is smaller than that of the two monitoring points in the straight outlet conduit without a division pier. There are differences in the main frequency and the power spectrum corresponding to the main frequency of the monitoring points in the straight outlet conduit, and the reasonable setting of the division pier is conducive to reducing the pressure pulsation of the flow in the straight outlet conduit and is beneficial to the safe and stable operation of the pump device.

Foetal bypass: concepts and controversies

Perfusion ◽  
1998 ◽  
Vol 13 (2) ◽  
pp. 111-117 ◽  
Author(s):  
Joseph J Sistino
Keyword(s):  
Heart Defects ◽  
Open Heart Surgery ◽  
Axial Flow ◽  
Right Atrial ◽  
Cyclooxygenase Inhibitors ◽  
Pump System ◽  
Maternal Risk ◽  
Valvular Stenosis ◽  
Axial Flow Pump ◽  
Flow Pump

One of the most controversial and challenging surgical undertakings of the next century promises to be foetal cardiac surgery. Animal studies have been underway for several years to gain an understanding of the physiological mechanisms required to achieve this undertaking. Not since the days of crosscirculation has there been a maternal risk associated with open-heart surgery. The diagnosis of congenital heart defects with foetal ultrasound can now be made as early as 12 weeks gestation. Simple cardiac abnormalities, such as valvular stenosis or atresia, alter intracardiac flow patterns and affect normal cardiac chamber development. Without early intervention, these complex lesions often require major surgical reconstruction, beginning in the neonatal period. Foetal cardiac bypass techniques have evolved from the use of roller pumps and bubble oxygenators primed with maternal blood to the use of an axial flow pump incorporated in a right atrial to pulmonary artery or aortic shunt. Because the blood entering the right atrium is oxygenated by the placenta, an oxygenator in the bypass circuit is probably not needed. The low prime axial flow pump system avoids the dilution of the foetus with the maternal adult haemoglobin and improves the outcome. A major focus of research has concentrated on maintenance of placental blood flow with the use of vasodilators and cyclooxygenase inhibitors. Investigation with primates will be necessary to confirm the placental physiology before human operations can be performed. As the foetal bypass challenges are overcome, there is the potential for a reduction in the number of complex cardiac lesions requiring early surgical intervention in the twenty-first century.

Performance evaluation of an axial-flow pump with adjustable guide vanes in turbine mode

2016 ◽  
Vol 99 ◽  
pp. 1146-1152 ◽  
Author(s):  
Zhongdong Qian ◽  
Fan Wang ◽  
Zhiwei Guo ◽  
Jie Lu
Keyword(s):  
Performance Evaluation ◽  
Axial Flow ◽  
Guide Vanes ◽  
Axial Flow Pump ◽  
Turbine Mode ◽  
Flow Pump

The Effect of the Thickness and Angle of the Inlet and Outlet Guide Vane on the Performance of Axial-Flow Pump

2016 ◽  
Author(s):  
Sang-Won Kim ◽  
Youn-Jea Kim
Keyword(s):  
Numerical Analysis ◽  
Numerical Study ◽  
Guide Vane ◽  
Axial Flow ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Pump Performance ◽  
Blade Thickness ◽  
Axial Flow Pump ◽  
Flow Pump

An axial-flow pump has a relatively high discharge flow rate and specific speed at a relatively low head and it consists of an inlet guide vane, impeller, and outlet guide vane. The interaction of the flow through the inlet guide vane, impeller, and outlet guide vane of the axial-flow pump has a significant effect on its performance. Of those components, the guide vanes especially can improve the head and efficiency of the pump by transforming the kinetic energy of the rotating flow, which has a tangential velocity component, into pressure energy. Accordingly, the geometric configurations of the guide vanes such as blade thickness and angle are crucial design factors for determining the performance of the axial-flow pump. As the reliability of Computational Fluid Dynamics (CFD) has been elevated together with the advance in computer technology, numerical analysis using CFD has recently become an alternative to empirical experiment due to its high reliability to measure the flow field. Thus, in this study, 1,200mm axial-flow pump having an inlet guide vane and impeller with 4 blades and an outlet guide vane with 6 blades was numerically investigated. Numerical study was conducted using the commercial CFD code, ANSYS CFX ver. 16.1, in order to elucidate the effect of the thickness and angle of the guide vanes on the performance of 1,200mm axial-flow pump. The stage condition, which averages the fluxes between interfaces and is accordingly appropriate for the evaluation of pump performance, was adopted as the interface condition between the guide vanes and the impeller. The rotational periodicity condition was used in order to enable a simplified geometry to be used since the guide vanes feature multiple identical regions. The shear stress transport (SST) k-ω model, predicting the turbulence within the flow in good agreement, was also employed in the CFD calculation. With regard to the numerical simulation results, the characteristics of the pressure distribution were discussed in detail. The pump performance, which will determine how well an axial-flow pump will work in terms of its efficiency and head, was also discussed in detail, leading to the conclusion on the optimal blade thickness and angle for the improvement of the performance. In addition, the total pressure loss coefficient was considered in order to investigate the loss within the flow paths depending on the thickness and angle variations. The results presented in this study may give guidelines to the numerical analysis of the axial-flow pump and the investigation of the performance for further optimal design of the axial-flow pump.

Numerical and Experimental Investigation of Tip Leakage Vortex Trajectory in an Axial Flow Pump

2013 ◽  
Author(s):  
Desheng Zhang ◽  
Weidong Shi ◽  
Suqing Wu ◽  
Dazhi Pan ◽  
Peipei Shao ◽  
...  
Keyword(s):  
Flow Rate ◽  
Axial Flow ◽  
Tip Clearance ◽  
High Speed Photography ◽  
Rate Condition ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Starting Point ◽  
Axial Flow Pump ◽  
Flow Pump

In this paper, the tip leakage vortex (TLV) structures in an axial flow pump were investigated by numerical and experimental methods. Based on the comparisons of different blade tip clearance size (i.e., 0.5 mm, 1mm and 1.5mm) and different flow rate conditions, TLV trajectories were obtained by Swirling Strength method, and simulated by modified SST k-ω turbulence model with refined high-quality structured grids. A high-speed photography test was carried out to capture the tip leakage vortex cavitation in an axial flow pump with transparent casing. Numerical results were compared with the experimental leakage vortex trajectories, and a good agreement is presented. The detailed trajectories show that the start point of tip leakage vortex appears near the leading edge at small flow rate, and it moves from trailing edge to about 30% chord span at rated flow rate. At the larger flow rate condition, the starting point of TLV shifts to the middle of chord, and the direction of TLV moves parallel to the blade hydrofoil. As the increasing of the tip size, the start point of TLV trajectories moves to the central of chord and the minimum pressure in vortex core is gradually reduced.

Interactional Effects of Inlet Guide Vane and Blade Angle on Hydraulic Performance Characteristics of a Submersible Axial-Flow Pump

2018 ◽  
Author(s):  
Youn-Sung Kim ◽  
Hyeon-Seok Shim ◽  
Kwang-Yong Kim
Keyword(s):  
Stokes Equations ◽  
Guide Vane ◽  
Incidence Angle ◽  
Axial Flow ◽  
Performance Characteristics ◽  
Inlet Guide Vane ◽  
Computational Domain ◽  
Blade Angle ◽  
Axial Flow Pump ◽  
Flow Pump

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.

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