Twenty-Fourth Symposium on Naval Hydrodynamics (2003) / Chapter Skim
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A 2D+T VOF Fully Coupled Formulation for Calculation of Breaking Free Surface Flow
A 2D+T VOF Fully Coupled Formulation for Calculation of Breaking Free Surface Flow
Pages 282-295
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From page 282... ...
The novelty in our code is the used at the same time a Volume Of Fluid capturing method and a verry accurateFully Coupled formulation to solve the Navier Stokes equation. In order to simulate an interface flow two different methods exist the front capturing method and the front tracking method.
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From page 283... ...
which are obtained from the second Navier-Stokes equation ( 1 1~. The integral form of this advection equation is used with a finite volume method for the spatial discretization.
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, and for low aspect ratio planning boats or slender displacement hull((B/L)
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From page 285... ...
· Oscillating flow in a tank has been simulated t151. This problem is used to compare our code to another CFD code using front tracking method, and to experimental data, showing good results.
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From page 286... ...
The difference with the last simulation is the addition of an obstacle in the bottom of the tank creating a water set of water which bounce up from the upper left corner of the obstacle in the direction of the opposite wall. Then the free surface has a very complex interface as it is presented in the fig.
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From page 287... ...
The first step try to reproduce a monochromatic wave field, without breaking wave and check the accuracy with theoretical solution. The wave is generated with a piston wave makers as it have been discussed previously in the wavemaker section.
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From page 288... ...
~ Conclusion and Perspective We have presented here a new numerical method using both advantages: The accuracy of the Fully Coupled algorithm first tested on Finite Differences convective formulation for tracking interface method and the robustness of Volume of Fluid capturing method to simulate very complex interfaces. The two dimensional test cases show that we achieved our first objective.: the two dimensional solver is robust and evade over a wide range of hydrodynamics applications.
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From page 289... ...
- —amp ~ -A -an aim - Figure 1 1: collapse of a dam at different instant: t = 0.2, 0.2, 0.4, 0.6, 1.0
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Figure 12: Rayleigh Taylor instability at instant: O.Os;0.4s;0.8s;1.2s;1.6s;2.0s;2.4s;2.8s
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. t~5.0000 t:33.0000 10 20 30 40 5XO 60 io 80 90 100 Figure 13: numerical wave tank at different instant.
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results Fn=0.289 . Figure 15: free surface elevation along the hull Figure 16: Wave field around the Wigley hull: Fn=0.289
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Figure 17: Wave field around the Wigley hull: Fn=0.7 Figure 18: Wave field around the Wigley hull: Fn=l.O
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From page 294... ...
X Vasseur, Etude Numerique de techniques d'acceleration de convergence lors de la resolution des equations de Navier-Stokes en Formulation Decouplee ou Fortement Couplee.
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From page 295... ...
However, at such Froude numbers transverse waves still play a role; and transverse waves cannot be modeled by 2D+t. Transverse wave length here is about 0.5L, and this may well explain some of the disagreement.
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