Numerical study of harbor oscillations induced by water surface disturbances within harbors of constant depth

2018 ◽  
Vol 68 (12) ◽  
pp. 1663-1681 ◽  
Author(s):  
Junliang Gao ◽  
Xiaojun Zhou ◽  
Li Zhou ◽  
Jun Zang ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Water Surface ◽  
Numerical Study ◽  
Constant Depth ◽  
Harbor Oscillations ◽  
Surface Disturbances

scholarly journals 3D Numerical Study of the Flow Properties in a Double-Spur Dikes Field during a Flood Process

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1574 ◽  
Author(s):  
Xun Han ◽  
Pengzhi Lin
Keyword(s):  
Water Surface ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Field Measurements ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
River Bed ◽  
Hydrodynamic Evolution ◽  
Spur Dikes ◽  
Potential Damage

A 3D numerical model is developed to study the flow characteristics of a double-spur dikes field on Yangtze River during a flood process, which was presented by the variation of the flow condition. The model is based on Navier–Stokes (NS) equations, the porous medium method (PMM) is employed to treat the solid structures including the river bed surface, the volume of fluid (VOF) method is applied to track the motion of the water surface during the flood process, and large eddy simulation (LES) is adopted to capture the turbulence transport and dissipation. Using this model, the target reach’s flow field before the construction of double-spur dikes is simulated first, while the numerical results are compared to the field measurements on flow velocity and water surface level, and fairly good agreements are shown. Then, the model is applied to reproduce the hydrodynamic evolution during a flood process after double-spur dikes’ constructions, while the detailed 3D flow fields are obtained under some certain states with different submergence rates of the spur dikes; finally, the potential damage positions around these spur dikes are analyzed accordingly.

Numerical Study on Boiling Mechanism and Rapid Phase Transfer Phenomenon of LNG Discharging on Water

2012 ◽  
Vol 516-517 ◽  
pp. 97-106 ◽  
Author(s):  
Bin Zhang ◽  
Wan Qing Wu ◽  
Jian Wei Zhang
Keyword(s):  
Mass Transfer ◽  
Transfer Rate ◽  
Water Surface ◽  
Phase Transfer ◽  
Numerical Study ◽  
Mass Transfer Rate ◽  
Initial Time ◽  
Rapid Phase ◽  
Boiling Mechanism ◽  
Superheat Limit

Abstract. Aiming at analyzing boiling mechanism and confirming rapid phase Abstract. Aiming at analyzing boiling mechanism and confirming rapid phase transfer (RPT) taking place conditions of LNG discharging on water. The models of pool spreading, heat and mass transfer rate and LNG’s property are coupled in this paper. The conditions of RPT has been confirmed, which included LNG directly contacting with water and the water temperature should higher than LNG’s superheat limit temperature, but the RPT would not take place if the LNG boils on ice. The model of LNG discharging on water has been established in this paper, which is used to simulate Boe and Burro-9 experiments. The results showed that the models can simulate evaporation and boiling rate well, and can be used in predicting the initial time of RPT happening when the discharging process is calm and the location of discharging is near the water surface.

The downstream effect of closing a barrier across an estuary with particular reference to the Thames

1959 ◽  
Vol 251 (1266) ◽  
pp. 426-439 ◽  
Keyword(s):  
Water Level ◽  
Water Surface ◽  
Reasonable Agreement ◽  
Damping Factor ◽  
Gradual Change ◽  
Shallow Water Theory ◽  
Constant Depth ◽  
Surface Level ◽  
Steady Velocity ◽  
Linear Shallow Water Theory

The theory given in this paper considers the reflected surge experienced downstream due to closing a tidal barrier across an estuary during a rising tide or storm surge. The estuary considered is exponential in width and of constant depth, and the discussion is based on linear shallow-water theory with friction taken proportional to the velocity in accord with Lorentz’s linearization of Chezy’s law. In the calculation of the surge, the initial non-steadiness of the motion of the water in the estuary, due to the original tidal action, is neglected. The theory finds the surge initiated when a steady velocity is brought impulsively or otherwise to rest at the barrier. Shortly after closure the resultant water level is obtained by adding the transient surge, obtained in this way, to the tidal curve for the unobstructed estuary. Expressions are obtained for the reflected surge which occurs seawards of the barrier for the three cases, namely, complete instantaneous closure, a state approximating partial instantaneous closure and gradual closure. For example, in the case of instantaneous closure, the surge at any point downstream of the barrier begins with a bore followed by a more gradual change of the water surface level. The height of the bore is shown to fall off seawards as (width of estuary) -1/2 x (an exponential damping factor dependent on the friction). The theory is applied to the proposed Thames Tidal Barrier and the results are in reasonable agreement with model tests.

scholarly journals Numerical study on transient harbor oscillations induced by solitary waves

2016 ◽  
Vol 126 ◽  
pp. 467-480 ◽  
Author(s):  
Junliang Gao ◽  
Chunyan Ji ◽  
Yingyi Liu ◽  
Oleg Gaidai ◽  
Xiaojian Ma ◽  
...  
Keyword(s):  
Solitary Waves ◽  
Numerical Study ◽  
Harbor Oscillations

Three-dimensional numerical study of flow structure in channel confluences

2010 ◽  
Vol 37 (5) ◽  
pp. 772-781 ◽  
Author(s):  
Ahmad Shakibainia ◽  
Mohammad Reza Majdzadeh Tabatabai ◽  
Amir Reza Zarrati
Keyword(s):  
Froude Number ◽  
Flow Structure ◽  
Flow Separation ◽  
Water Surface ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
River System ◽  
Control Flow ◽  
Secondary Currents

Channel confluence is one of the important features of each river system and some hydraulic structures. The features that can dominantly control flow characteristics in a confluence are confluence angle, discharge, width ratios, and Froude number of flow. Several research studies have been conducted however a comprehensive three-dimensional (3-D) numerical study of flow characteristics in a confluence has not yet been reported. In the present study, SSIIM2.0, a 3-D numerical model, is validated and applied to investigate secondary currents, velocity distribution, flow separation, and water surface elevation in different conditions. The results of the present study illustrate that flow structure and water surface variations in a confluence are highly influenced by confluence angle, discharge, and width ratios as well as Froude number because of their effect on flow deflection, separation, and secondary currents. The graphs from the present study can be used to analyze water surface variation, velocity field, and flow separation dimensions in difference conditions for engineering designs.

A Numerical Study of the Thrust Generation from a Honeybee Wing Model near the Water Surface

2021 ◽  
Author(s):  
Dominic D. Chandar ◽  
Niamh Carlin ◽  
Shashank K Karanth ◽  
Awie Viljoen ◽  
Wei Hua Ho
Keyword(s):  
Water Surface ◽  
Numerical Study ◽  
Wing Model ◽  
Thrust Generation

scholarly journals Change in Transverse Slope of Water Surface at River Bend: A Numerical Study

2021 ◽  
Vol 12 (2) ◽  
pp. 93-101
Author(s):  
Priyata Rahman ◽  
Md Shahjahan Ali
Keyword(s):  
Turbulent Flows ◽  
Water Surface ◽  
River Flow ◽  
Numerical Study ◽  
Flow Behavior ◽  
Flow Simulation ◽  
3D Models ◽  
Radius Of Curvature ◽  
Secondary Current ◽  
Transverse Slope

Generation of secondary current in a meandering river flow due to the centrifugal force acting on the bend is three dimensional (3D) in nature. But in case of practical problems like alluvial geomorphic processes, 3D models are not proved to be efficient. Hence, two dimensional (2D) models are generally adopted for such problems. This study offers a presentation of numerical simulation results for turbulent flows around bends of a meandering channel for different meander angles. 2D models were built by the use of iRIC Nays2DH solver for flow simulation of 45˚, 90˚, 135˚, 180˚ meandering bends with varying widths of 0.15m, 0.25m, 0.75m, 1.00m, 1.25m and 1.50m considering constant Froude number with constant meandering length (ML/W) and constant radius of curvature (R/W). Zero equation model was used as turbulence closure with finite differential advections as upwind scheme. The flow behavior has been studied at the apex and cross over portions of bends. From the simulation, the velocity at outer bank was found to be lower than that of the inner bank while the water surface elevation was found to be higher than that of the inner bank. Increase in transverse slope of water surface at bend was observed for increasing meander angles, Froude numbers and decreasing channel widths. Journal of Engineering Science 12(2), 2021, 93-101

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