Numerical study of pressure forcing of wind on dynamically evolving water waves

2010 ◽  
Vol 22 (4) ◽  
pp. 041704 ◽  
Author(s):  
Yi Liu ◽  
Di Yang ◽  
Xin Guo ◽  
Lian Shen
Keyword(s):  
2013 ◽  
Vol 45 (5) ◽  
pp. 055506 ◽  
Author(s):  
Belgacem Ghozlani ◽  
Zouhaier Hafsia ◽  
Khlifa Maalel

Author(s):  
Manases Tello Ruiz ◽  
Marc Mansuy ◽  
Guillaume Delefortrie ◽  
Marc Vantorre

When approaching or leaving a port a ship often needs to perform manoeuvres in the presence of waves. At the same time the water depth is still limited for deep drafted vessels. For manoeuvring simulation purposes this requires a manoeuvring model which includes phenomena such as short crested waves and squat effects. The present paper addresses the manoeuvring problem in shallow water waves numerically and experimentally. The numerical study is conducted by means of potential theory, incorporating first and second order exciting wave forces, and their superposition to the calm water manoeuvring models. The applicability of such an approach is also investigated. The experimental work has been conducted at Flanders Hydraulics Research (in cooperation with Ghent University) with a scale model of an ultra large container vessel. Captive model tests comprise harmonic yaw tests and steady straight line tests with and without waves, at different forward speeds, wave frequencies and amplitudes, in head and following waves. Waves are chosen to represent conditions commonly met by ships in the Belgian coastal zone of the North Sea.


2006 ◽  
Author(s):  
Claudio Zanzi ◽  
Pablo Go´mez ◽  
Julia´n Palacios ◽  
Joaqui´n Lo´pez ◽  
Julio Herna´ndez

A numerical study of the impact of shallow-water waves on vertical walls is presented. The air-liquid flow was simulated using a code for incompressible viscous flow, based on a local level set algorithm and a second-order approximate projection method. The level set transport and reinitialization equations were solved in a narrow band around the interface using an adaptive refined grid. The wave is assumed to be generated by a plunger which is accelerated in an open channel containing water. An arbitrary Lagrangian-Eulerian method was used to take into account the relative movement between the plunger and the end wall of the channel. The evolution of the free surface was visualized using a laser light sheet and a high-speed camera, with a sampling frequency of 1000 Hz. Several simulations were carried out to investigate the influence of the shape of the wave approaching the wall on the relevant quantities associated with the impact. The wave shape just before the impact was changed varying the total length of the channel. The results are compared with experimental results and with results obtained by other authors.


2017 ◽  
Vol 158 ◽  
pp. 107-119 ◽  
Author(s):  
Bing-Qing Deng ◽  
Yi Hu ◽  
Xin Guo ◽  
Robert A. Dalrymple ◽  
Lian Shen

1996 ◽  
Vol 322 ◽  
pp. 1-19 ◽  
Author(s):  
M. Ioualalen ◽  
A. J. Roberts ◽  
C. Kharif

A numerical study of the superharmonic instabilities of short-crested waves on water of finite depth is performed in order to measure their time scales. It is shown that these superharmonic instabilities can be significant-unlike the deep-water case-in parts of the parameter regime. New resonances associated with the standing wave limit are studied closely. These instabilities ‘contaminate’ most of the parameter space, excluding that near two-dimensional progressive waves; however, they are significant only near the standing wave limit. The main result is that very narrow bands of both short-crested waves ‘close’ to two-dimensional standing waves, and of well developed short-crested waves, perturbed by superharmonic instabilities, are unstable for depths shallower than approximately a non-dimensional depth d= 1; the study is performed down to depth d= 0.5 beyond which the computations do not converge sufficiently. As a corollary, the present study predicts that these very narrow sub-domains of short-crested wave fields will not be observable, although most of the short-crested wave fields will be.


Author(s):  
Marcio Michiharu Tsukamoto ◽  
Liang-Yee Cheng ◽  
Kazuo Nishimoto

The motion of floating bodies linked elastically to the bottom of seas and waterways is of great interest in the analysis of the wave suppressing devices, such as wave breakers, and the behaviors of the floating structures, such as buoys and tension leg platforms (TLP). For the modeling of the dynamics, the coupling between the hydrodynamic loads due to waves and the restoring forces due to the elastic link must be considered. In some simpler cases, the analytical approaches are available. However, in case of large amplitude waves and floating bodies with complex geometries, the analytical solutions do not give accurate results. In the present study, a numerical model based on MPS (moving particle semi-implicit method) for the hydrodynamic loads coupled with the Hook’s Law for the restoring force is adopted to analyze the motion of floating bodies with one or several elastic links to the bottom of shallow water under large amplitude waves. Initially, the results of 2D numerical simulation of simple oscillating buoys are compared with the analytical and experimental ones to validate the numerical approach. After that, the approach is applied to the study of the shallow water wave supressing devices. Heave, surge and pitching motions of the floaters are assessed as well as the hydrodynamic coefficients to show the effect of the elastic links in the nonlinear wave hydrodynamics.


2015 ◽  
Vol 21 (3) ◽  
pp. 289-309
Author(s):  
Shuyang Cao ◽  
Enzhen Zhang ◽  
Liming Sun ◽  
Jinxin Cao

Sign in / Sign up

Export Citation Format

Share Document