scholarly journals Numerical Investigation on Generation and Propagation Characteristics of Offshore Tsunami Wave under Landslide

2020 ◽  
Vol 10 (16) ◽  
pp. 5579
Author(s):  
Junkai Sun ◽  
Yang Wang ◽  
Cheng Huang ◽  
Wanhu Wang ◽  
Hongbing Wang ◽  
...  
Keyword(s):  
Tsunami Wave ◽  
Wave Train ◽  
Coupled Model ◽  
Immersed Boundary ◽  
Propagation Mode ◽  
Short Axis ◽  
Wave Component ◽  
Sliding Angle ◽  
Large Wave ◽  
Subaerial Landslide

Tsunamis induced by the landslide will divide into a traveling wave component propagating along the coastline and an offshore wave component propagating perpendicular to the coastline. The offshore tsunami wave has the non-negligible energy and destruction in enclosed basins as fjords, reservoirs, and lakes, which are worth studying. The initial submergence condition, the falling height and sliding angle of slider, are important reference indexes of damage degree of landslide and may also matter at that of the landslide-induced tsunami. Depending on the fully coupled model, the effects of them on the production and propagation of the tsunami were considered in the study. Since the slider used was semi-elliptic, the effect of the ratio of the long axis to the short axis was also analyzed. According to the computational fluid dynamics theory, a numerical wave tank was developed by the immersed boundary (IB) method; besides, the general moving-object module of slide mass was also embedded to the numerical tanker. The results indicate that the effects of the squeezing and pushing of the slider on water produce a naturally attenuated wave at the front of the wave train, and the attenuation becomes more serious with the increase in the initial submersion range of the slider. The effects of the vertical movement of the slider cause the increase in the amplitude of the back of the wave train. As the falling height increases, the large wave height increases when the slider is initially submerged and decreases when it is not initially submerged, except for the accidental elevation of that at smaller falling heights. The results also indicate that the hazard of the subaerial landslide-induced tsunami is greater under a small or large falling angle, and that of the partial subaerial and submarine landslide-induced tsunami is greater under a small falling angle. With the increase in the ratio of the long axis to the short axis, the total induced wave energy decreases and the shape of the wave train proportionally reduces, while the wave propagation mode does not change.

On the Westward Turning of Hurricane Sandy (2012): Effect of Atmospheric Intraseasonal Oscillations

2019 ◽  
Vol 32 (20) ◽  
pp. 6859-6873
Author(s):  
Liudan Ding ◽  
Tim Li ◽  
Baoqiang Xiang ◽  
Melinda Peng
Keyword(s):  
Wave Train ◽  
Intraseasonal Oscillation ◽  
Coupled Model ◽  
Tropical Indian Ocean ◽  
Circulation Pattern ◽  
Hurricane Sandy ◽  
Economic Losses ◽  
Observational Analysis ◽  
The North ◽  
Steering Flow

Abstract Hurricane Sandy (2012) experienced an unusual westward turning and made landfall in New Jersey after its northward movement over the Atlantic Ocean. The landfall caused severe casualties and great economic losses. The westward turning took place in the midlatitude Atlantic where the climatological mean wind is eastward. The cause of this unusual westward track is investigated through both observational analysis and model simulations. The observational analysis indicates that the hurricane steering flow was primarily controlled by atmospheric intraseasonal oscillation (ISO), which was characterized by a pair of anticyclonic and cyclonic circulation systems. The anticyclone to the north was part of a global wave train forced by convection over the tropical Indian Ocean through Rossby wave energy dispersion, and the cyclone to the south originated from the tropical Atlantic through northward propagation. Hindcast experiments using a global coupled model show that the model is able to predict the observed circulation pattern as well as the westward steering flow 6 days prior to Sandy’s landfall. Sensitivity experiments with different initial dates confirm the important role of the ISO in establishing the westward steering flow in the midlatitude Atlantic. Thus the successful numerical model experiments suggest a potential for extended-range dynamical tropical cyclone track predictions.

Highly oscillatory properties of unsteady ship waves

2000 ◽  
Vol 214 (6) ◽  
pp. 813-823 ◽  
Author(s):  
X-B Chen
Keyword(s):  
Free Surface ◽  
Dispersion Curves ◽  
Wave Component ◽  
Large Wave ◽  
Ship Waves ◽  
Potential Flows ◽  
Highly Oscillatory ◽  
Parabolic Form ◽  
Single Integral ◽  
Oscillatory Properties

The singular and highly oscillatory properties of unsteady ship waves are studied by considering potential flows generated by a point source pulsating and advancing at a uniform forward speed located close to or at the free surface. The wave component of the free-surface potential defined by Noblesse and Chen by a single integral along the dispersion curves defined by the dispersion relation is analysed by developing asymptotic expansions of the open dispersion curves at large wave numbers. The asymptotic analysis of the wave component contributed by the leading asymptotic term of a parabolic form shows that unsteady ship waves are highly oscillatory with infinitely increasing amplitude and infinitely decreasing wavelength, when a field point approaches the track of the source point at the free surface. The highly oscillatory property and complex singular behaviour of unsteady ship waves are further expressed in an original and analytically closed form.

On the formation of sediment chains in an oscillatory boundary layer

2016 ◽  
Vol 789 ◽  
pp. 461-480 ◽  
Author(s):  
Marco Mazzuoli ◽  
Aman G. Kidanemariam ◽  
Paolo Blondeaux ◽  
Giovanna Vittori ◽  
Markus Uhlmann
Keyword(s):  
Boundary Layer ◽  
Stokes Equations ◽  
Coupled Model ◽  
Spherical Particles ◽  
Navier Stokes ◽  
Immersed Boundary ◽  
Navier Stokes Equations ◽  
Ripple Formation ◽  
Oscillatory Boundary Layer ◽  
Parameter Ranges

The dynamics of spherical particles resting on a horizontal wall and set into motion by an oscillatory flow is investigated by means of a fully coupled model. Both a smooth wall and a rough wall, the latter being composed of resting particles with a random arrangement and with the same diameter as the moving particles, are considered. The fluid and particle motions are determined by means of direct numerical simulations of Navier–Stokes equations and Newton’s laws, respectively. The immersed boundary approach is used to force the no-slip condition on the surface of the particles. In particular, the process of formation of transverse sediment chains, within the boundary layer but orthogonal to the direction of fluid oscillations, is simulated in parameter ranges matching those of laboratory experiments investigating rolling-grain ripple formation. The numerical results agree with the experimental observations and show that the transverse sediment chains are generated by steady recirculating cells, generated by the interaction of the fluid and particle oscillations.

On the scattering of short surface waves by a finite dock

1968 ◽  
Vol 64 (4) ◽  
pp. 1109-1129 ◽  
Author(s):  
F. G. Leppington
Keyword(s):  
Wave Train ◽  
Normal Incidence ◽  
Great Depth ◽  
Travelling Wave ◽  
Reflection And Transmission ◽  
Large Wave ◽  
Transmission Coefficients ◽  
Weakly Coupled ◽  
Wave Trains ◽  
Induced Velocity

AbstractA sinusoidal travelling wave-train is at normal incidence upon a two-dimensional finite dock fixed on the surface of a body of water of great depth, and the problem investigated herein is that of finding the limiting form of the induced velocity potential for short waves. Of particular interest are the amplitudes of the wave-trains reflected and transmitted towards infinity by such an obstacle. The potential is expressed as a sum of coupled semi-infinite dock potentials, whence results a pair of weakly coupled integral equations for the solution. This formulation of the problem is shown to be amenable to an approximate solution for large wave-numbers, and the first few terms are derived in formal expansions for the reflection and transmission coefficients.

Collision Analysis of Container Drifted by Runup Tsunami Using Drift Collision Coupled Model

2009 ◽  
Vol 4 (6) ◽  
pp. 441-449 ◽  
Author(s):  
Gyeong-Seon Yeom ◽  
◽  
Tomoaki Nakamura ◽  
Norimi Mizutani ◽  
Keyword(s):  
Coupled Model ◽  
Numerical Data ◽  
Wave Force ◽  
Immersed Boundary ◽  
Initial Condition ◽  
Force Estimation ◽  
Wave Runup ◽  
Collision Model ◽  
Drift Model ◽  
Collision Force

This study proposes analyzing tsunami generation and propagation of tsunamis, wave runup onto land, object drift, collision with other structures, deformation prediction of colliding and collided-with, and collision force estimation. To reduce calculation load in using the LS-DYNA collision model, we use a drift model using the immersed boundary (IB) method from wave generation to just before collision, and the collision model is used during the collision phase, in which numerical data calculated using the drift model are used as an initial condition of the collision model. Validity of the drift model for wave level, wave force, and drift behavior of a container were verified through comparison with experimental data measured in laboratory experiments. Collision model predictability was also confirmed in terms of drift collision force. Fluid-structure interaction (FSI) between the container and the runup wave is reproduced in numerical drift collision analysis. Through this analysis of a full-scale container based on the international standard with a concrete column, we confirmed the applicability of the collision analysis using the drift simulation as an initial condition for an actual field.

scholarly journals Study on Analytical Modelling of Tsunami Wave Propagation

2020 ◽  
Author(s):  
Yasmin Regina M ◽  
Syed Mohamed E
Keyword(s):  
Wave Propagation ◽  
Arrival Time ◽  
Tsunami Wave ◽  
Wave Train ◽  
Deep Ocean ◽  
Vital Role ◽  
The People ◽  
Run Up ◽  
Short Time ◽  
Tsunami Amplitude

Modelling of tsunami wave propagation plays a vital role in forecasting of disastrous tsunami. The earlier identification and prediction of tsunami provides more time for taking preventive measures and evacuation. On December 26, 2004, massive destruction of lives and properties due to tsunami increases the needs to develop a fast and accurate modelling of tsunami wave propagation. The modelling of waves provide the amplitude of tsunami, speed, arrival time and power of the wall of water and also run up distance and height. It also used to predict vulnerable buildings to tsunami. In this paper describes the modelling of tsunami wave propagation from generation to run-up. Numerical and analytical methods used for modelling and simulation. Tsunami is serious of wave (wave train) which has a long wavelength >500 km and celerity of wave more than 800 km/hr in deep ocean and in shallow coast, their wavelength and celerity diminishes but the amplitude of wave increases above 30m. The scope of this study is to determine the areas which are going to hit by tsunami, amplitude of wave and their arrival time for early forecasting and alert the people within a short time after an earthquake happened.

scholarly journals On kinematics of very steep waves

2013 ◽  
Vol 13 (8) ◽  
pp. 2101-2107 ◽  
Author(s):  
L. Shemer
Keyword(s):  
Wave Breaking ◽  
Wide Spectrum ◽  
Wave Train ◽  
Vertical Acceleration ◽  
Wave Group ◽  
Third Order ◽  
Large Wave ◽  
The Third ◽  
Steep Waves ◽  
Group Velocities

Abstract. Experiments on extremely steep deterministic waves generated in a large wave tank by focusing of a broad-banded wave train serve as a motivation for the theoretical analysis of the conditions leading to wave breaking. Particular attention is given to the crest of the steepest wave where both the horizontal velocity and the vertical acceleration attain their maxima. Analysis is carried out up to the third order in wave steepness. The apparent, Eulerian and Lagrangian accelerations are computed for wave parameters observed in experiments. It is demonstrated that for a wave group with a wide spectrum, the crest propagation velocity differs significantly from both the phase and the group velocities of the peak wave. Conclusions are drawn regarding the applicability of various criteria for wave breaking.

Accelerated warming in the northern midlatitude summer since the 1990s

2021 ◽  
Author(s):  
Haiyan Teng ◽  
Ruby Leung ◽  
Grant Branstator ◽  
Jian Lu ◽  
Qinghua Ding
Keyword(s):  
Climate Models ◽  
Wave Train ◽  
Coupled Model ◽  
Wave Model ◽  
Warming Trend ◽  
Forced Response ◽  
Regional Warming ◽  
Arctic Regions ◽  
Rossby Wave Train ◽  
A Chain

<p>The northern midlatitude summer has experienced rapid warming since the 1990s, especially in Europe, Central Siberia-Mongolia, the West Coast of North America as well as several continental Arctic regions. These “hot spots” are connected by a chain of high-pressure ridges from an anomalous wavenumber-5 Rossby wave train in the upper troposphere.  Here by cross-examining reanalysis datasets and a suite of Coupled Model Intercomparison Project Phase 6 (CMIP6) baseline experiments, we demonstrate that the anthropogenically forced response may be intertwined with internal multidecadal variability, making it difficult to partition the 1979-2020 trend with state-of-the-art climate models. Instead, we take a “storyline” approach with a planetary wave model and sensitivity experiments with an Earth system model to explore key underlying driving factors. Our results highlight the importance of multiscale interaction with synoptic eddy via atmosphere-ocean and atmosphere-land coupling in shaping the multidecadal regional warming trend which has enormous socioeconomic implications. </p>

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