scholarly journals 3-D numerical simulation of the tidal circulation in the Gulf of Tonkin, Vietnam

2001 ◽  
Vol 23 (2) ◽  
pp. 116-128
Author(s):  
Phan Ngoc Vinh ◽  
Nguyen Kim Dan
Keyword(s):  
Numerical Simulation ◽  
Water Surface ◽  
Bottom Topography ◽  
Free Water ◽  
System Transformation ◽  
Tidal Circulation ◽  
Turbulence Mixing ◽  
Gulf Of Tonkin ◽  
Quang Ninh ◽  
Good Agreement

The purpose of this paper is to present 3-D numerical simulation of the tidal circulation in the Gulf of Tonkin. A sigma-coordinate system transformation is used to make possible a total fitting between the computing point-grid and the bottom topography as well as the free water surface. A turbulence-closure sub-model K-L which permits the parameterization of the turbulence mixing is also included. The studied domain, the whole Gulf of Tonkin, extends from the coastal zone of Quang-Ninh into Thua Thien Hue province and as far as Hai-Nam (China) island seawards. The model have been calibrated and verified by the observed data at six different stations for a three and seven-day periods. The results are in good agreement with the observed data. The kinetic energy distribution was considered.

Numerical Simulation of Shock Wave / Free-water Surface Interaction

2017 ◽  
Vol 2017.55 (0) ◽  
pp. K0405
Author(s):  
Keita MATSUURA ◽  
M. M. A. ALAM ◽  
Manabu TAKAO ◽  
Toshiaki SETOGUCHI
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Water Surface ◽  
Free Water ◽  
Surface Interaction ◽  
Free Water Surface

Simulations of an Air-Ventilated Strut Crossing Water Surface at Variable Yaw Angles

2018 ◽  
Author(s):  
Konstantin I. Matveev ◽  
Miles P. Wheeler ◽  
Tao Xing
Keyword(s):  
Water Surface ◽  
Free Water ◽  
Suction Side ◽  
Complex Flow ◽  
Air Ventilation ◽  
History Of ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Lift Control ◽  
Good Agreement

Hydrodynamic devices intended to produce lift, control actions, or propulsion can be prone to air ventilation when operating near the free water surface. The atmospheric air may propagate to the low-pressure zones around these devices located under the nominal water level. This often leads to performance degradation of hydrodynamic systems. Modeling of air-ventilated flows is challenging due to complex flow nature and many factors in play. In this study, the computational fluid dynamics simulations are carried out for a surface-piercing strut at different yaw angles. At small yaw angles, the strut underwater surfaces remain wetted, whereas at large yaw and sufficiently high Froude numbers the suction side becomes air ventilated. At the intermediate yaw angles, both wetted and ventilated flow regimes are possible, and the existence of a specific state depends on the history of the process. The present computational results demonstrate good agreement with available experimental data.

Finite Element Simulations and Experimental Investigations of Simple 2-D Geometries in Slamming

2008 ◽  
Author(s):  
Adrian Constantinescu ◽  
Alain Neme ◽  
Nicolas Jacques ◽  
Philippe Rigo
Keyword(s):  
Finite Element ◽  
Water Surface ◽  
Free Water ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Convergence Criterion ◽  
Numerical Work ◽  
Fluid Structure ◽  
The Impact ◽  
Good Agreement

This paper presents a numerical and experimental study of fluid structure interaction during the impact of a solid body on a water surface. The main request is the modeling of the slamming forces acting on the ship structure in severe sea conditions. The numerical work uses the finite element modeling of a structure impact with free water surface. The first analysis use the commercial finite element code ABAQUS/Standard and combines the assumption of small displacements for the ideal fluid and the solid with an asymptotic formulation for accurate pressure evaluation on the boundary of the wet surface. For deformable strickers, two methods are developed. The first method employs a weak fluid-structure coupling. The second method, more accurate, uses an implicit fluid-structure coupling using a convergence criterion. The second analysis is represented by the simulations of slamming with ABAQUS/Explicit. The simulation uses a viscous, compressible fluid and a soft-exponential law to manage the contact between fluid and solid. The results in term of pressure and total effort applied to the rigid structure are in good agreement with first numerical results and especially with the FLUENT CFD. In order to validate the numerical methods, slamming experimental tests were carried out with a new hydraulic shock press at the ENSIETA laboratory.

Numerical Simulation and its Application in Configuration Optimization of a Spillway Tunnel

2012 ◽  
Vol 170-173 ◽  
pp. 1660-1664
Author(s):  
Lian Feng Xu
Keyword(s):  
Numerical Simulation ◽  
Numerical Experiment ◽  
Turbulent Flow ◽  
Computer Program ◽  
Turbulence Model ◽  
Water Surface ◽  
Free Water ◽  
Configuration Optimization ◽  
Proposed Model ◽  
Spillway Tunnel

Based on the turbulence characteristics of spillway, a turbulence model for simulating turbulent flow with free water surface under a body-fitted coordinate is established and a computer program is developed for numerical experiment in this paper. A spillway flow is numerically simulated, and the results are quite fitted with the experimental ones. Thus, the proposed model is also applied to the spillway tunnel optimization.

Numerical Simulation of Flow over a Spillway with Turbulence Model

2011 ◽  
Vol 90-93 ◽  
pp. 2511-2515
Author(s):  
Chuan Qi Li ◽  
Jie Gong ◽  
Xiang Fu Li
Keyword(s):  
Turbulence Model ◽  
Water Surface ◽  
Three Dimensional ◽  
Free Water ◽  
Coupling Scheme ◽  
Volume Of Fluid Method ◽  
Experiment Data ◽  
Three Dimensional Flow ◽  
Simulation Results ◽  
Good Agreement

In this paper, the Standard k- ε equation turbulence model was used to simulate three-dimensional flow over a spillway. The volume of fluid method (VOF) was introduced into the iteration of calculation to solve the free water surface, and segregated solver was used with the PISO pressure-velocity coupling scheme. The free surface, the magnitude and distribution of the velocity, the pressure on the spillway surface and so on were obtained. The simulation results were in good agreement with the experiment data.

Three-Dimensional Numerical Simulation of the Hydraulic Characteristics of Spillway in Gushitan Reservoir

2012 ◽  
Vol 256-259 ◽  
pp. 2403-2406
Author(s):  
Shu Guang Jing ◽  
Xue Ping Gao ◽  
Lai Fei Jia ◽  
Li Ping Xu
Keyword(s):  
Numerical Simulation ◽  
Water Surface ◽  
Three Dimensional ◽  
Simulation Method ◽  
Vof Method ◽  
Hydraulic Characteristics ◽  
Bottom Pressure ◽  
Surface Profiles ◽  
Simulation Results ◽  
Good Agreement

Based on standard k-ε turbulence model and the VOF method for tracking free surface, hydraulic characteristics of the spillway in Gushitan Reservoir are simulated with a 3-D numerical model. The discharge capacity, water surface profiles, bottom pressure distribution and flow pattern are studied. Numerical simulation results have been in good agreement with experimental results, showing fine feasibility to study hydraulic characteristics of the spillway with the VOF method. The hydraulic characteristics acquired by the numerical simulation method can be used for spillway design.

Measuring and Numerical Simulation of the Free Water Surface of the Open Pump Suction

2007 ◽  
Author(s):  
Gang Chen ◽  
Yulin Wu ◽  
Yi Fan ◽  
Guangjun Cao ◽  
Zhaofeng Xu
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Water Surface ◽  
Free Water ◽  
Rectangular Section ◽  
Open Type ◽  
Free Water Surface ◽  
System A ◽  
Flow Situation ◽  
Water Height

Detailed measurements of the free water surface of the open pump suction were obtained by PIV system. A step was arranged in the rectangular section of the model open type suction passage. The data have been measured with different conditions, such as the height of step (hs), averaged velocity (v) near the entrance of the open type suction passage, and the water height (h) near the chest wall. The existence of the step influences the flow situation greatly, when hs is higher, the flow situation becomes more turbulent. Near the end edge of the step, there were obvious drops of the water surface. When flow-velocity becomes bigger and water depth decreases, the flowing situations become more turbulent. Also, we calculated the free water surface at the open pump suction passage using the VOF method and the calculated results were coincided with the experimental data obtained under the same conditions. The results showed that the usefulness of PIV in obtaining the free water surface and validated the numerical model in simulation the open pump suction.

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