Solitary Waves to Infer Axial Stress in Slender Structures: A Numerical Model

2015 ◽  
pp. 47-57
Author(s):  
Abdollah Bagheri ◽  
Piervincenzo Rizzo ◽  
Leith Al-Nazer
Keyword(s):  
Numerical Model ◽  
Solitary Waves ◽  
Axial Stress ◽  
Slender Structures

Runup of solitary waves on a circular Island

1995 ◽  
Vol 302 ◽  
pp. 259-285 ◽  
Author(s):  
Philip L. -F. Liu ◽  
Yong-Sik Cho ◽  
Michael J. Briggs ◽  
Utku Kanoglu ◽  
Costas Emmanuel Synolakis
Keyword(s):  
Numerical Model ◽  
Solitary Waves ◽  
Large Scale ◽  
Wave Equations ◽  
Laboratory Data ◽  
Two Dimensional ◽  
Wave Trapping ◽  
Shallow Water Wave Equations ◽  
Circular Island ◽  
Run Up

This is a study of the interactions of solitary waves climbing up a circular island. A series of large-scale laboratory experiments with waves of different incident height-to-depth ratios and different crest lengths is described. Detailed two-dimensional run-up height measurements and time histories of surface elevations around the island are presented. A numerical model based on the two-dimensional shallow-water wave equations including runup calculations was developed. Numerical model predictions agreed very well with the laboratory data and the model was used to study wave trapping and the effect of slope. Under certain conditions, enhanced runup and wave trapping on the lee side of the island were observed, suggesting a possible explanation for the devastation reported by field surveys in Babi Island off Flores, Indonesia, and in Okushiri Island, Japan.

scholarly journals Run-Up of Solitary Waves on Twin Conical Islands Using a Boussinesq Model

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Dongfang Liang ◽  
Alistair G. L. Borthwick ◽  
Jonathan K. Romer-Lee
Keyword(s):  
Numerical Model ◽  
Solitary Waves ◽  
Laboratory Data ◽  
Boussinesq Model ◽  
Reflected Waves ◽  
Wave Refraction ◽  
Local Wave ◽  
Run Up ◽  
Gap Spacing ◽  
Incident Waves

This paper investigates the interaction of solitary waves (representative of tsunamis) with idealized flat-topped conical islands. The investigation is based on simulations produced by a numerical model that solves the two-dimensional Boussinesq-type equations of Madsen and Sørensen using a total variation diminishing Lax–Wendroff scheme. After verification against published laboratory data on solitary wave run-up at a single island, the numerical model is applied to study the maximum run-up at a pair of identical conical islands located at different spacings apart for various angles of wave attack. The predicted results indicate that the maximum run-up can be attenuated or enhanced according to the position of the second island because of wave refraction, diffraction, and reflection. It is also observed that the local wave height and hence run-up can be amplified at certain gap spacing between the islands, owing to the interference between the incident waves and the reflected waves between islands.

An Analytical Investigation of the Trapeze Effect Acting on a Thin Flexible Ribbon

2014 ◽  
Vol 81 (12) ◽  
Author(s):  
Jérôme F. Sicard ◽  
Jayant Sirohi
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Stress Field ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Axial Stress ◽  
Analytical Investigation ◽  
Pure Bending ◽  
Torsional Coupling ◽  
Tip Mass

This paper systematically explores the extensional–torsional coupling due to the trapeze effect acting on a thin flexible ribbon subjected to combined tension and torsion. Kinematic relationships as well as expressions for the restoring torque associated with this effect are analytically derived. Additionally, the locus of points about which the cross sections of a twisted ribbon under tension rotate is derived. These points, called torsional centers, are found to be coincident with the centroids of the axial stress field at each station along the ribbon. More generally, it is shown that when a flexible slender member is in tension, combined transverse forces must act at the centroid of the axial stress field to produce pure bending and no twist. As a result, the elastic axis (EA) of the member shifts from the locus of shear centers to the locus of centroids of the axial stress field. A numerical model is developed to investigate the effect of the position of the EA on the prediction of steady-state deformations and natural frequencies of a rotating ribbon with tip mass. By assuming the EA to be the locus of the shear centers, the tip twist is overpredicted by a factor of 2 for small twist angles, and up to 2.5 for large twist deformations. In addition, assuming the EA to be the locus of shear centers results in an error of up to 60% in the predicted natural frequencies at large twist angles.

scholarly journals Numerical Simulation for the Evolution of Internal Solitary Waves Propagating over Slope Topography

2021 ◽  
Vol 9 (11) ◽  
pp. 1224
Author(s):  
Yingjie Hu ◽  
Li Zou ◽  
Xinyu Ma ◽  
Zhe Sun ◽  
Aimin Wang ◽  
...  
Keyword(s):  
Numerical Model ◽  
Solitary Wave ◽  
Solitary Waves ◽  
Wave Amplitude ◽  
Domain Boundary ◽  
Internal Solitary Wave ◽  
Internal Solitary Waves ◽  
Initial Amplitude ◽  
Nonlinear Potential ◽  
Slope Topography

In this study, the propagation and evolution characteristics of internal solitary waves on slope topography in stratified fluids were investigated. A numerical model of internal solitary wave propagation based on the nonlinear potential flow theory using the multi-domain boundary element method was developed and validated. The numerical model was used to calculate the propagation process of internal solitary waves on the topography with different slope parameters, including height and angle, and the influence of slope parameters, initial amplitude, and densities jump of two-layer fluid on the evolution of internal solitary waves is discussed. It was found that the wave amplitude first increased while climbing the slope and then decreased after passing over the slope shoulder based on the calculation results, and the wave amplitude reached a maximum at the shoulder of the slope. A larger height and angle of the slope can induce larger maximum wave amplitude and more obvious tail wave characteristics. The wave amplitude gradually decreased, and a periodic tail wave was generated when propagating on the plateau after passing the slope. Both frequency and height of the tail wave were affected by the geometric parameters of the slope bottom; however, the initial amplitude of the internal solitary wave only affects the tail wave height, but not the frequency of the tail wave.

scholarly journals Numerical modelling of disintegration of basin-scale internal waves in a tank filled with stratified water

2005 ◽  
Vol 12 (6) ◽  
pp. 955-964 ◽  
Author(s):  
N. Stashchuk ◽  
V. Vlasenko ◽  
K. Hutter
Keyword(s):  
Numerical Model ◽  
Internal Waves ◽  
Solitary Waves ◽  
Mixing Processes ◽  
Wave Regime ◽  
Stratified Lakes ◽  
Low Dissipation ◽  
Basin Scale ◽  
Shear Instabilities ◽  
Set Up

Abstract. We present the results of numerical experiments performed with the use of a fully non-linear non-hydrostatic numerical model to study the baroclinic response of a long narrow tank filled with stratified water to an initially tilted interface. Upon release, the system starts to oscillate with an eigen frequency corresponding to basin-scale baroclinic gravitational seiches. Field observations suggest that the disintegration of basin-scale internal waves into packets of solitary waves, shear instabilities, billows and spots of mixed water are important mechanisms for the transfer of energy within stratified lakes. Laboratory experiments performed by D. A. Horn, J. Imberger and G. N. Ivey (JFM, 2001) reproduced several regimes, which include damped linear waves and solitary waves. The generation of billows and shear instabilities induced by the basin-scale wave was, however, not sufficiently studied. The developed numerical model computes a variety of flows, which were not observed with the experimental set-up. In particular, the model results showed that under conditions of low dissipation, the regimes of billows and supercritical flows may transform into a solitary wave regime. The obtained results can help in the interpretation of numerous observations of mixing processes in real lakes.

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