Validation Study for Free-Surface Wave Flows Around Surface-Piercing Cylindrical Structures

2005 ◽  
Author(s):  
Shin Hyung Rhee ◽  
Boris Makarov
Keyword(s):  
Free Surface ◽  
Surface Wave ◽  
Breaking Waves ◽  
Navier Stokes ◽  
Test Cases ◽  
Ship Waves ◽  
Cylindrical Structures ◽  
Free Surface Waves ◽  
Free Surface Wave ◽  
Wave Flows

The present study is concerned with the free-surface wave flows around surface-piercing cylindrical structures. The volume of fluid method implemented in a Navier-Stokes computational fluid dynamics code is employed for test cases that involve general ship waves, spilling breaking waves, bubbly free-surface in separated regions, and interaction between free-surface waves and underlying viscous flow. The computational results are validated against existing experimental data, showing good agreement. The validation results suggest that the present computational approach provides a tool that is flexible and accurate enough to capture the outstanding flow physics associated with the free-surface wave flows around surface-piercing cylindrical structures.

The Application of Numerical Methods for the Solution of Some Problems in Free-Surface Hydrodynamics

2005 ◽  
Vol 49 (04) ◽  
pp. 288-301
Author(s):  
U. P. Bulgarelli
Keyword(s):  
Free Surface ◽  
Numerical Methods ◽  
Stokes Equations ◽  
Level Set Methods ◽  
Breaking Waves ◽  
Free Surface Flows ◽  
Navier Stokes ◽  
Robust Algorithms ◽  
Ship Waves ◽  
Particle Hydrodynamics

The aim of this contribution is to present some of the recent developments achieved at INSEAN in the context of accurate and robust algorithms for the solutions of the system of partial differential equations governing complex free-surface flows. The paper addresses several problems of relevant interest in naval hydrodynamics, for example, sloshing, water on deck, microscale breaking waves, bow-stern flows, ship waves, steady and unsteady ship flows. Each problem is solved through the most appropriate numerical method, which is selected on the basis of the approximations that can be done for the particular problem and of the kind of result that the analysis has to provide. Numerical methods adopted involve classical boundary element approaches, smoothed particle hydrodynamics, heterogeneous domain decomposition techniques, level-set methods, steady and unsteady Reynolds averaged Navier-Stokes equations. Validation versus experimental data are presented. Comparisons among different numerical approaches are also established in a few cases with the aim of highlighting their limits and/or capabilities.

Free-Surface Wave-Induced Separation

1996 ◽  
Vol 118 (3) ◽  
pp. 546-554 ◽  
Author(s):  
Z. J. Zhang ◽  
F. Stern
Keyword(s):  
Fluid Dynamics ◽  
Free Surface ◽  
Surface Wave ◽  
Navier Stokes ◽  
Surface Boundary ◽  
Flow Conditions ◽  
Continuity Equations ◽  
Surface Boundary Conditions ◽  
Free Surface Wave ◽  
Wave Induced

Free-surface wave-induced separation is studied for a surface-piercing NACA 0024 foil over a range of Froude numbers (0, .2, .37, .55) through computational fluid dynamics of the unsteady Reynolds-averaged Navier-Stokes and the continuity equations with the Baldwin-Lomax turbulence model, exact nonlinear kinematic and approximate dynamic free-surface boundary conditions, and a body/free-surface conforming grid. The flow conditions and uncertainty analysis are discussed. A topological rule for a surface-piercing body is derived and verified. Steady-flow results are presented and analyzed with regard to the wave and viscous flow and the nature of the separation.

Large amplitude progressive interfacial waves

1979 ◽  
Vol 93 (3) ◽  
pp. 433-448 ◽  
Author(s):  
Judith Y. Holyer
Keyword(s):  
Free Surface ◽  
Surface Wave ◽  
Surface Waves ◽  
Large Amplitude ◽  
Phase Speed ◽  
Maximum Height ◽  
Interfacial Waves ◽  
Free Surface Waves ◽  
Lower Fluid ◽  
Over The Top

This paper contains a study of large amplitude, progressive interfacial waves moving between two infinite fluids of different densities. The highest wave has been calculated using the criterion that it has zero horizontal fluid velocity at the interface in a frame moving at the phase speed of the waves. For free surface waves this criterion is identical to the criterion due to Stokes, namely that there is a stagnation point at the crest of each wave. I t is found that as the density of the upper fluid increases relative to the density of the lower fluid the maximum height of the wave, for fixed wavelength, increases. The maximum height of a Boussinesq wave, which has the density almost the same above and below the interface, is 2·5 times the maximum height of a surface wave of the same wavelength. A wave with air over the top of it can be about 2% higher than the highest free surface wave. The point at which the limiting criterion is first satisfied moves from the crest for free surface waves to the point half-way between the crest and the trough for Boussinesq waves. The phase speed, momentum, energy and other wave properties are calculated for waves up to the highest using Padé approximants. For free surface waves and waves with air above the interface the maximum value of these properties occurs for waves which are lower than the highest. For Boussinesq waves and waves with the density of the upper fluid onetenth of the density of the lower fluid these properties each increase monotonically with the wave height.

Numerical Simulation of Flows Past Partially-Submerged Horizontal Circular Cylinders in Free Surface Waves

2013 ◽  
Author(s):  
Hans Bihs ◽  
Muk Chen Ong
Keyword(s):  
Free Surface ◽  
Surface Waves ◽  
Wave Theory ◽  
Circular Cylinders ◽  
Navier Stokes ◽  
Wave Forces ◽  
Linear Wave ◽  
Numerical Wave Tank ◽  
Linear Wave Theory ◽  
Free Surface Waves

Two-dimensional (2D) numerical simulations are performed to investigate the flows past partially-submerged circular cylinders in free surface waves. The 2D simulations are carried out by solving the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with the k-ω turbulence model. The level set method is employed to model the free-surface waves. Validation studies of a numerical wave tank have been performed by comparing the numerical results with the analytical results obtained from the linear-wave theory. Wave forces on the partially-submerged cylinders have been calculated numerically and compared with the published theoretical and experimental data under regular-wave conditions. The free-surface elevations around the cylinders have been investigated and discussed.

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