scholarly journals TRIDIMENSIONAL NUMERICAL MODEL FOR TIDAL AND WIND GENERATED FLOW

1982 ◽  
Vol 1 (18) ◽  
pp. 41
Author(s):  
M.C. Burg ◽  
A. Marluzel ◽  
Y. Coeffe
Keyword(s):  
Free Surface ◽  
Hydrostatic Pressure ◽  
Numerical Model ◽  
Finite Difference Method ◽  
Vertical Profile ◽  
Three Dimensional ◽  
Mixing Length ◽  
Gironde Estuary ◽  
Laboratory Flume ◽  
Prismatic Channel

This report presents a three-dimensional numerical model, which calculates by a finite-difference method the vertical profile of horizontal velocities. The unsteady three-dimensional Navier-Stok.es equations with a free surface are governing this flow. We assume a hydrostatic pressure, and simulate the turbulent effects by the Prandtl's mixing-length hypothesis. The model is validated by experiments carried out in a laboratory flume with a prismatic channel inclined 45° over the flow. Then, the model is applied successfully in Gironde estuary and coastal areas in France for the computation of tidal and wind generated currents.

Three-dimensional numerical model for open-channels with free-surface variations

2003 ◽  
Vol 41 (1) ◽  
pp. 110-112
Author(s):  
ZhixiaN. Cao ◽  
Rodney Day ◽  
Sarah Liriano
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Three Dimensional ◽  
Open Channels

scholarly journals Three dimensional numerical simulations for non-breaking solitary wave interacting with a group of slender vertical cylinders

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Weihua Mo ◽  
Philip L.-F. Liu
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Dynamic Pressure ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Time History ◽  
Surface Displacement ◽  
Numerical Results ◽  
Finite Volume Scheme ◽  
Free Surface Displacement

AbstractIn this paper we validate a numerical model for-structure interaction by comparing numerical results with laboratory data. The numerical model is based on the Navier-Stokes(N-S) equations for an incompressible fluid. The N-S equations are solved by two-step projection finite volume scheme and the free surface displacements are tracked by the slender vertical piles. Numerical results are compared with the laboratory data and very good agreement is observed for the time history of free surface displacement, fluid particle velocity and force. The agreement for dynamic pressure on the cylinder is less satisfactory, which is primarily caused by instrument errors.

A Semi-Implicit 3-D Numerical Model Using Sigam-Coordinate for Non-Hydrostatic Pressure Free-Surface Flows

2011 ◽  
Vol 23 (2) ◽  
pp. 212-223 ◽  
Author(s):  
De-chao Hu ◽  
Bei-lin Fan ◽  
Guang-qian Wang ◽  
Hong-wu Zhang
Keyword(s):  
Free Surface ◽  
Hydrostatic Pressure ◽  
Numerical Model ◽  
Free Surface Flows ◽  
Surface Flows

scholarly journals Numerical Simulation of Wind-Driven Circulation in a Thermally Stratified Flow

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Jin Woo Lee ◽  
He-Rin Cho ◽  
Yong-Sik Cho
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Environmental Pollutants ◽  
Three Dimensional ◽  
Internal Flow ◽  
Stratified Flow ◽  
Vertical Circulation ◽  
Rectangular Basin ◽  
Closed Water ◽  
Wind Driven Circulation

The closed water bodies, such as reservoirs and lakes, can be polluted by an inflow of pollutants in the upstream as well as a stratification caused by seasonal natural phenomena. The vertical circulation particularly plays an important role in reducing environmental pollutants. The factors of the vertical circulation are the temperature, wind, thermal diffusivity, sunlight, and so on. The wind is the most significant factor among all possible factors causing the vertical circulation. Thus, it is necessary to describe the validation and application of a three-dimensional numerical model of wind-driven circulation in a thermally stratified flow. In this study, the numerical model is conducted in three steps to calculate the velocity components from the momentum equations inx- andy-directions, the elevations from the free surface equation, and the temperature from the scalar transport equation. The present model was applied to two tests for verification of the numerical accuracy. Numerical results are compared with analytical solutions of the sloshing free surface movement in a rectangular basin and the model is applied to the circulation for the wind-driven flow in a thermal stratification. Consequently, the developed model is validated by two verifications and phenomena of the internal flow.

scholarly journals Numerical Study of Violent Impact Flow Using a CIP-Based Model

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Qiao-ling Ji ◽  
Xi-zeng Zhao ◽  
Sheng Dong
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Large Scale ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Small Scale ◽  
Surface Boundary ◽  
Two Phase ◽  
Constrained Interpolation

A two-phase flow model is developed to study violent impact flow problem. The model governed by the Navier-Stokes equations with free surface boundary conditions is solved by a Constrained Interpolation Profile (CIP)-based high-order finite difference method on a fixed Cartesian grid system. The free surface is immersed in the computation domain and expressed by a one-fluid density function. An accurate Volume of Fluid (VOF)-type scheme, the Tangent of Hyperbola for Interface Capturing (THINC), is combined for the free surface treatment. Results of another two free surface capturing methods, the original VOF and CIP, are also presented for comparison. The validity and utility of the numerical model are demonstrated by applying it to two dam-break problems: a small-scale two-dimensional (2D) and three-dimensional (3D) full scale simulations and a large-scale 2D simulation. Main attention is paid to the water elevations and impact pressure, and the numerical results show relatively good agreement with available experimental measurements. It is shown that the present numerical model can give a satisfactory prediction for violent impact flow.

3D SPH Numerical Investigation for the Sloshing Impact in LNG Tank

2013 ◽  
Author(s):  
Zhigang Bai ◽  
Jun Zhao ◽  
Wei Zhang ◽  
Weiling Wang
Keyword(s):  
Free Surface ◽  
Numerical Model ◽  
Numerical Technique ◽  
Three Dimensional ◽  
Liquid Sloshing ◽  
Dynamic Responses ◽  
Sph Method ◽  
Sph Model ◽  
Lng Tank ◽  
Liquid Natural Gas

Sloshing in liquid natural gas (LNG) tankers includes extremely large deformations of the free surface. To better understand such deformations, a three-dimensional Smoothed Particle Hydrodynamics (SPH) method is developed to analyze the dynamic responses of liquid sloshing in LNG tank. The numerical model solves the Euler equation in the SPH style, the Monaghan-type artificial viscosity has been used in the current SPH model, sloshing wall boundaries were treated by improved coupling boundary pressure treatment. The numerical model is first validated against experimental data for two-dimensional and three-dimensional liquid sloshing in a LNG tank, it shows a fair agreement of overall fluid motions and hydrodynamic pressures. The fields of 3D sloshing pressure and velocity are compared for one period. Finally, the model is used to study 3D liquid sloshing in a tank with vertical baffles. The effect of the baffle on pressure and velocity is investigated and discussed. It shows that the SPH method is a natural numerical technique for coupled fluid-structure problems with large free-surface deformations.

scholarly journals Numerical model of energy dissipation and shallow-water sloshing motions in tank under different coupled excitations

2021 ◽  
Author(s):  
Yan Su
Keyword(s):  
Free Surface ◽  
Energy Dissipation ◽  
Numerical Model ◽  
Shallow Water ◽  
Three Dimensional ◽  
Wave Crest ◽  
Surface Boundary ◽  
Transient Wave ◽  
Irregular Free Surface ◽  
Free Surface Oscillations

AbstractShallow-water sloshing motions in a three-dimensional rectangular tank are investigated. The Boussinesq-type equations in terms of velocity potential and the finite-difference scheme are applied for the solutions of numerical model. Through linking the rate of decay of the wave amplitudes to the energy dissipation due to the friction at the tank walls, a linear damping term is proposed and added into the free surface boundary condition. Taking the tank under excited frequencies near the lowest natural frequency, the maximum transient wave amplitudes and steady-state wave amplitudes of sloshing motions at the tank wall are presented and verified by the experimental results given in the literature. The characteristics of sloshing motions in tank under different coupled excitations are studied. The results indicate that coupled surge-sway excitations lead to the weaker nonlinear sloshing motions in tank than the single degree of freedom excitations. The intersection of sloshing wave crest lines finally tend to the diagonal line of the tank under the coupled surge-sway excitations with different amplitudes. And the irregular free surface oscillations appear at the corners of the tank excited by the coupled surge-sway-roll-pitch-yaw harmonic motions.

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