scholarly journals Analysis of the Flow Pattern and Flow Rectification Measures of the Side-Intake Forebay in a Multi-Unit Pumping Station

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2025
Author(s):  
Ahmed Nasr ◽  
Fan Yang ◽  
Yiqi Zhang ◽  
Tieli Wang ◽  
Mahmoud Hassan
Keyword(s):  
Numerical Simulation ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Flow Pattern ◽  
Three Dimensional ◽  
Operating Efficiency ◽  
Water Tank ◽  
Three Dimensional Model ◽  
Pumping Station ◽  
Area Reduction

To improve the problem of turbulence in the forebay of the lateral inlet pumping station, a typical lateral inlet pumping station project in Xuzhou, Jiangsu Province, China was taken as the research object. The forebay of the pumping station is a building connecting the river channel and the pumping station into the water tank. Based on the Reynolds-averaged Navier-Stokes (RANS) law and the turbulence model, the computational fluid dynamics method (CFD) technology compares and analyzes the numerical simulation with or without rectification measures for the forebay of the lateral intake pumping station when multiple units are operating. The three-dimensional model was created by SolidWorks modeling software and the numerical simulation simulated by CFX-ANSYS. To alter the flow pattern in the forebay of the pumping station, various rectification measures were chosen. Internal rectification flow patterns in the forebay under multiple plans, uniformity of flow velocity distribution in the measuring section, and vortex area reduction rates are investigated and compared. Based on the analysis and comparison of numerical simulation results, when the parabolic wall and some rectification piers are set significantly it improves the flow pattern of the forebay of the lateral inlet pumping station. It also makes the flow pattern of the inlet pool better and increases the uniformity of the flow velocity distribution by 8%. Further, it reduced the vortex area by 70%, effectively improving the operating efficiency of the pump. The research results of this paper provide a technical reference for the improvement of the flow pattern in the forebay of the lateral inlet pumping station.

scholarly journals Study on the Rectification of Forebay in Pumping Station

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Weiwei Song ◽  
Yong Pang ◽  
Xiaohuan Shi ◽  
Qing Xu
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Three Dimensional ◽  
Bottom Layer ◽  
Control Measures ◽  
Three Dimensional Model ◽  
Inlet Channel ◽  
Pumping Station ◽  
Pump Station ◽  
Comparison Of The Results

The forebay of pumping stations is an important hydraulic structure that connects the channel with the inlet channel. Actual test observations and theoretical studies have shown that poor precursors produce backflow, vortex, and water flow disturbances in the forebay water. In this paper, taking a lateral inlet pump station as an example, we study the nonmeasures and five rectification measures—“Y” type diversion pier, “T” shaped diversion pier, narrow bottom hole, high and wide bottom, and diversion wall—through adopting the method of numerical simulation and model test. For the numerical simulation, the corresponding three-dimensional model is established by UG solid modeling software, and then the computational fluid is simulated numerically with CFX. Based on the analysis and comparison of the results during the test of numerical simulation and model test, the stability of the rectification measures is considered after taking into consideration the results of the uniformity test of the velocity distribution of the surface layer, the bottom layer, and the front section of each scheme. The proposed scheme 3 (“T” diversion pier) is regarded as the pumping station flow control measures.

scholarly journals Research on Parametric Design of Hydraulic Retarder Based on Multi-Field Coupling of Heat, Fluid and Solid

2015 ◽  
Vol 9 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Kuiyang Wang ◽  
Jinhua Tang ◽  
Guoqing Li
Keyword(s):  
Numerical Simulation ◽  
Parametric Design ◽  
Design Method ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Field Coupling ◽  
Sequential Coupling ◽  
Fluid Coupling ◽  
Hydraulic Retarder

In order to optimize the design method and improve the performance of hydraulic retarder, the numerical simulation of multi-field coupling of heat, fluid and solid is carried out to hydraulic retarder, based on the numerical computation and algorithm of heat-fluid coupling and fluid-solid coupling. The computation models of heat-fluid coupling and fluid-solid coupling of hydraulic retarder are created. The three dimensional model of hydraulic retarder is established based on CATIA software, and the whole flow passage model of hydraulic retarder is extracted on the basis of the three dimensional model established. Based on the CFD calculation and the finite element numerical simulation, the temperature field, stress field, deformation and stress state are analysised to hydraulic retarder in the state of whole filling when the rotate speed is 1600 r/min. In consideration of rotating centrifugal force, thermal stress and air exciting vibration force of blade surface, by using the sequential coupling method, the flow field characteristics of hydraulic retarder and dynamic characteristics of blade structure are analysised and researched based on multi-field coupling of heat, fluid and solid. These provide the theoretical foundation and references for parametric design of hydraulic retarder.

Numerical Simulation of Impacts of Different Types of Air Duct Outlets on Ventilation Efficiency

2013 ◽  
Vol 438-439 ◽  
pp. 1098-1103
Author(s):  
Chun Zi Nan ◽  
Ji Ming Ma ◽  
Luo Zhao
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Numerical Method ◽  
Concentration Effect ◽  
Mixing Zone ◽  
Mixing Effect ◽  
Ventilation Efficiency ◽  
Different Types

To enhance the exhaust efficiency during ventilation, three types of air duct outlets were imported. According to the characteristics of velocity distribution simulated by numerical method, the flow field is divided into the mixing zone and the exhaust zone. The gradual contracted air duct outlet can enhance the mixing effect between fresh air and smoke. In the exhaust zone, however, the flow velocity on the upper section of the tunnel is weakened, which is unfavorable for smoke exhaust. Gradual expanded air duct outlet, on the contrary, may weaken the concentration effect of the airflow. The flow velocity on the upper section of the tunnel is increased in the exhaust zone, thus the flow field is more homogenized, which is in favor of smoke exhaust.

Aerodynamic Behavior of Asymmetric Jets in 3-D Furnaces

1994 ◽  
Author(s):  
F. M. El-Mahallawy ◽  
M. A. Hassan ◽  
M. A. Ismail ◽  
H. Zafan
Keyword(s):  
Numerical Simulation ◽  
Flow Pattern ◽  
Numerical Experiments ◽  
Recirculation Zone ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Flow Region ◽  
Stabilization Method ◽  
Flow Features

The purpose of this paper is to present and evaluate numerical experiments illustrating the flow features in a 3-D furnace utilizing unconventional asymmetrical jet that creates natural recirculation zone. The numerical simulation of this aerodynamic stabilization method have unveiled the three-dimensional nature of the flow pattern which possesses a quite large reverse flow region. The size and strength of the built recirculation zone would be capable of stabilizing the burning of low-quality fuels.

Three-Dimensional Numerical Analysis of Horizontal and Vertical Coalescence of Bubbles at Two Submerged Horizontal Orifices on the Wall

2019 ◽  
Author(s):  
Z. P. Li ◽  
L. Q. Sun ◽  
X. L. Yao ◽  
Y. Piao
Keyword(s):  
Numerical Simulation ◽  
Internal Pressure ◽  
Three Dimensional ◽  
Ventilation Rate ◽  
Smoothing Technique ◽  
Dimensional Model ◽  
Mesh Smoothing ◽  
Three Dimensional Model ◽  
Coalescence Time ◽  
Ventilation Rates

Abstract In the process of bubbling from two submerged adjacent orifices, bubbles coalescence becomes inevitable. But the study of the evolution and interaction of bubbles from submerged orifices is little, especially numerical simulation. In this paper, combined with mesh smoothing technique, mesh subdivision technique and the technique of axisymmetric coalescence and 3D coalescence, a three-dimensional model of bubbles coalescence at two submerged adjacent orifices on the wall is established by the boundary element method. Then, numerical simulations were carried out for horizontal and vertical coalescence before detachment. Finally, by changing the ventilation rate and the Froude number, the effects of different ventilation rates and buoyancy on the process of bubbles coalescence at two adjacent orifices were investigated. The results show that for horizontal coalescence, the effect of ventilation rate is more pronounced than buoyancy. As the ventilation rate increases or the influence of buoyancy is decreased, the amplitude of internal pressure fluctuation of the bubble decreases and the coalescence time decreases. For vertical coalescence, the effect of buoyancy is more pronounced than ventilation rate. With the influence of buoyancy is decreased, the vertical coalescence time is increased, the internal pressure of the bubble is decreased. The influence of ventilation rate is similar to that of horizontal coalescence.

Numerical Simulation on the Liquid Metal Flow of the Acceleration Phase in the Shot Sleeve of Cold Chamber Die Casting Process

2007 ◽  
Vol 561-565 ◽  
pp. 1801-1804
Author(s):  
Jie Yang ◽  
Lang Yuan ◽  
Shou Mei Xiong ◽  
Bai Cheng Liu
Keyword(s):  
Numerical Simulation ◽  
Liquid Metal ◽  
Metal Flow ◽  
Three Dimensional ◽  
Great Influence ◽  
Casting Process ◽  
Shot Sleeve ◽  
Three Dimensional Model ◽  
Acceleration Phase ◽  
Fill Ratio

Slow shot velocity and its acceleration phase in the shot sleeve have great influence on the flow pattern of the liquid metal in the shot sleeve. In this paper, a three-dimensional model based on the SOLA-VOF algorithm was developed and used to simulate the flow of melt in the shot sleeve. The mathematical model was verified by water analog experiments with constant plunger velocities. Based on numerical simulation results, the influences of the plunger acceleration on the wave profile of the liquid metal in the shot sleeve under different fill ratios and sleeve diameters were investigated. The results indicated that in order to avoid air entrapment in the shot sleeve, the optimal acceleration value to the critical slow shot velocity increases with the increase of the fill ratio, and the range of suitable acceleration becomes wider as well. With the same fill ratio, the value of suitable acceleration rises as the plunger diameter increases.

Strouhal numbers of rectangular cylinders

1982 ◽  
Vol 123 ◽  
pp. 379-398 ◽  
Author(s):  
Atsushi Okajima
Keyword(s):  
Reynolds Number ◽  
Wind Tunnel ◽  
Velocity Distribution ◽  
Flow Pattern ◽  
Strouhal Number ◽  
Vortex Shedding ◽  
Water Tank ◽  
Height Ratio ◽  
Rectangular Cylinders ◽  
Good Agreement

Experiments on the vortex-shedding frequencies of various rectangular cylinders were conducted in a wind tunnel and in a water tank. The results show how Strouhal number varies with a width-to-height ratio of the cylinders in the range of Reynolds number between 70 and 2 × l04. There is found to exist a certain range of Reynolds number for the cylinders with the width-to-height ratios of 2 and 3 where flow pattern abruptly changes with a sudden discontinuity in Strouhal number. The changes in flow pattern corresponding to the discontinuity of Strouhal number have been confirmed by means of measurements of velocity distribution and flow visualization. These data are compared with those of other investigators. The experimental results have been found to show a good agreement with those of numerical calculations.

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