1,720,989 research outputs found
Boundary conditions for modeling scattered wave field around floating bodies in elliptic wave models
No full textThis paper presents a new methodology to reproduce the interaction between waves and floating objects over mildly variable bathymetry. The elliptic mild slope equation solves the fluid velocity potential over a domain, which does not include the near field around each object. The waves scattered by the floating bodies are considered by means of boundary conditions at the edges of the near field areas. The coefficients of these boundary conditions are obtained nesting the solution of a near field three dimensional solver with the elliptic model solution. Comparison with a 3D numerical model, which solves the potential flow field over the whole domain, is used to validate the proposed approach. An example of application to reproduce the wave field around an array of wave energy converters is presented
Un nuovo modello numerico per la simulazione di batterie di convertitori di energia ondosa
No full textPropagation of tsunamis over large areas using COMSOL
No full textThis paper presents a numerical model
based on the mild-slope equation (MSE for
short) suitable to reproduce the propagation of
small amplitude tsunamis in the off-shore field.
The model solves the governing equations in the
frequency domain and allows the reproduction of
the frequency dispersion for broad banded
spectrum sea states. The model application to
reproduce laboratory experiments and real life
tsunamis in the south Tyrrhenian sea
(Mediterranean Sea) are described, showing its
applicability to relative large geographical areas.
The proposed method is suitable to support a real
time tsunami early warning system
New 2D laboratory experiments on wave overtopping at vertical walls under impulsive and non-impulsive conditions
No full textThis paper describes 2D physical model study on wave overtopping at vertical coastal structures. Results of two experimental campaigns are presented, where different wave and geometrical parameters are considered. Wide ranges of relative water depth at the toe of the structure and relative crest freeboard are explored, considering two foreshore slopes in front of the vertical wall. Wave–wall interactions both for pulsating and impulsive regime are tested. The wave overtopping time series measurement allows to analyze not only mean overtopping discharges but also individual overtopping volumes. Single overtopping volumes distribution is investigated relating it to geometrical and hydraulic parameters. The present experimental analysis is coherent with the literature, in the already explored range of wave and geometrical parameters of the structure; moreover, it extends the previous findings, providing two main outcomes: (i) new mean wave overtopping measurements for a wider ranges of relative water depth and relative freeboards; (ii) new individual wave overtopping volumes measurements at vertical walls, specifically under impulsive conditions. New insights on the mean overtopping discharge and on the probability distribution of individual overtopping volumes are provided
Role of Armor Roughness in Overtopping Response of Upgraded Multilayer Rubble Mound Breakwaters
No full textOn the Resonant Behavior of a Weakly Compressible Water Layer During Tsunamigenic Earthquakes
No full textTsunamigenic earthquakes trigger pressure waves in the ocean, given the weak compressibility of the sea water. For particular conditions, a resonant behavior of the water layer can occur, which influences the energy transfer from the sea-bed motion to the ocean. In this paper, the resonance conditions are explained and analyzed, focusing on the hydro-acoustic waves in the proximity of the earthquake area. A preliminary estimation of the generation parameters (sea-bed rising time, velocity) is given, by means of parametric numerical simulations for simplified conditions. The results confirm the importance of measuring, modeling, and interpreting such waves for tsunami early detection and warning
A depth-integrated equation for large scale modeling of tsunami in weakly compressible fluid
No full textPressure waves generated by fast seabed movement in weakly compressible sea water, namely hydro-acoustic waves travel at the sound celerity in water (about 1500 m/s). These waves are precursors of the counterpart long free-surface gravity waves and contain significant information on the tsunamigenic source. Measurement of hydro-acoustic waves can therefore anticipate the tsunami arrival and significantly enhance the promptness and accuracy of tsunami early warning systems. In this paper derivation of a novel depth-integrated numerical model for reproduction of hydroacoustic waves is presented and the application of this computationally ecient model on two devastating historical tsunamis of Mediterranean Sea in real bathymetry analyzed to reveal the eect of variable bathymetry. On the basis of the model results, some hints for deep sea observatory are given
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