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Letteratura scientifica selezionata sul tema "Wave models"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 13 febbraio 2022

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Articoli di riviste sul tema "Wave models"

Verao Fernandez, Gael, Vasiliki Stratigaki, Panagiotis Vasarmidis, Philip Balitsky e Peter Troch. "Wake Effect Assessment in Long- and Short-Crested Seas of Heaving-Point Absorber and Oscillating Wave Surge WEC Arrays". Water 11, n. 6 (29 maggio 2019): 1126. http://dx.doi.org/10.3390/w11061126.

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In the recent years, the potential impact of wave energy converter (WEC) arrays on the surrounding wave field has been studied using both phase-averaging and phase-resolving wave propagation models. Obtaining understanding of this impact is important because it may affect other users in the sea or on the coastline. However, in these models a parametrization of the WEC power absorption is often adopted. This may lead to an overestimation or underestimation of the overall WEC array power absorption, and thus to an unrealistic estimation of the potential WEC array impact. WEC array power absorption is a result of energy extraction from the incoming waves, and thus wave height decrease is generally observed downwave at large distances (the so-called “wake” or “far-field” effects). Moreover, the power absorption depends on the mutual interactions between the WECs of an array (the so-called “near field” effects). To deal with the limitations posed by wave propagation models, coupled models of recent years, which are nesting wave-structure interaction solvers into wave propagation models, have been used. Wave-structure interaction solvers can generally provide detailed hydrodynamic information around the WECs and a more realistic representation of wave power absorption. Coupled models have shown a lower WEC array impact in terms of wake effects compared to wave propagation models. However, all studies to date in which coupled models are employed have been performed using idealized long-crested waves. Ocean waves propagate with a certain directional spreading that affects the redistribution of wave energy in the lee of WEC arrays, and thus gaining insight wake effect for irregular short-crested sea states is crucial. In our research, a new methodology is introduced for the assessment of WEC array wake effects for realistic sea states. A coupled model is developed between the wave-structure interaction solver NEMOH and the wave propagation model MILDwave. A parametric study is performed showing a comparison between WEC array wake effects for regular, long-crested irregular, and short-crested irregular waves. For this investigation, a nine heaving-point absorber array is used for which the wave height reduction is found to be up to 8% lower at 1.0 km downwave the WEC array when changing from long-crested to short-crested irregular waves. Also, an oscillating wave surge WEC array is simulated and the overestimation of the wake effects in this case is up to 5%. These differences in wake effects between different wave types indicates the need to consider short-crested irregular waves to avoid overestimating the WEC array potential impacts. The MILDwave-NEMOH coupled model has proven to be a reliable numerical tool, with an efficient computational effort for simulating the wake effects of two different WEC arrays under the action of a range of different sea states.

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Zhang, Huichen, e Markus BrÃ¼hl. "GENERATION OF EXTREME TRANSIENT WAVES IN EXPERIMENTAL MODELS". Coastal Engineering Proceedings, n. 36 (30 dicembre 2018): 51. http://dx.doi.org/10.9753/icce.v36.waves.51.

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The transfer of natural waves and sea states into small- and large-scale model teste contributes to the proper design of offshore and coastal structure. Such shallow-water ocean surface waves are highly nonlinear and subject to wave transformation and nonlinear wave-wave interactions. However, the standard methods of wave generation according to conventional wave theories and wave analysis methods are limited to simple regular waves, simple sea states and low-order wave generation without considering the nonlinear wave-wave interactions. The research project Generation of Extreme Transient Waves in Experimental Models (ExTraWaG) aims to accurately generate target transient wave profile at a pre-defined position in the wave flume (transfer point) under shallow water conditions. For this purpose, the KdV-based nonlinear Fourier transform is introduced as a continuative wave analysis method and is applied to investigate the nonlinear spectral character of experimental wave data. Furthermore, the method is applied to generate transient nonlinear waves as specific locations in the wave flume, considering the nonlinear transformation and interactions of the propagating waves.

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BAL, GUILLAUME, e OLIVIER PINAUD. "IMAGING USING TRANSPORT MODELS FOR WAVE–WAVE CORRELATIONS". Mathematical Models and Methods in Applied Sciences 21, n. 05 (maggio 2011): 1071–93. http://dx.doi.org/10.1142/s0218202511005258.

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We consider the imaging of objects buried in unknown heterogeneous media. The medium is probed by using classical (e.g. acoustic or electromagnetic) waves. When heterogeneities in the medium become too strong, inversion methodologies based on a microscopic description of wave propagation (e.g. a wave equation or Maxwell's equations) become strongly dependent on the unknown details of the heterogeneous medium. In some situations, it is preferable to use a macroscopic model for a quantity that is quadratic in the wave fields. Here, such macroscopic models take the form of radiative transfer equations also referred to as transport equations. They can model either the energy density of the propagating wave fields or more generally the correlation of two wave fields propagating in possibly different media. In particular, we consider the correlation of the two fields propagating in the heterogeneous medium when the inclusion is absent and present, respectively. We present theoretical and numerical results showing that reconstructions based on this correlation are more accurate than reconstructions based on measurements of the energy density.

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Zappa, Giuseppe, Valerio Lucarini e Antonio Navarra. "Baroclinic Stationary Waves in Aquaplanet Models". Journal of the Atmospheric Sciences 68, n. 5 (1 maggio 2011): 1023–40. http://dx.doi.org/10.1175/2011jas3573.1.

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Abstract An aquaplanet model is used to study the nature of the highly persistent low-frequency waves that have been observed in models forced by zonally symmetric boundary conditions. Using the Hayashi spectral analysis of the extratropical waves, the authors find that a quasi-stationary wave 5 belongs to a wave packet obeying a well-defined dispersion relation with eastward group velocity. The components of the dispersion relation with k ≥ 5 baroclinically convert eddy available potential energy into eddy kinetic energy, whereas those with k < 5 are baroclinically neutral. In agreement with Green’s model of baroclinic instability, wave 5 is weakly unstable, and the inverse energy cascade, which had been previously proposed as a main forcing for this type of wave, only acts as a positive feedback on its predominantly baroclinic energetics. The quasi-stationary wave is reinforced by a phase lock to an analogous pattern in the tropical convection, which provides further amplification to the wave. It is also found that the Pedlosky bounds on the phase speed of unstable waves provide guidance in explaining the latitudinal structure of the energy conversion, which is shown to be more enhanced where the zonal westerly surface wind is weaker. The wave’s energy is then trapped in the waveguide created by the upper tropospheric jet stream. In agreement with Green’s theory, as the equator-to-pole SST difference is reduced, the stationary marginally stable component shifts toward higher wavenumbers, while wave 5 becomes neutral and westward propagating. Some properties of the aquaplanet quasi-stationary waves are found to be in interesting agreement with a low frequency wave observed by Salby during December–February in the Southern Hemisphere so that this perspective on low frequency variability, apart from its value in terms of basic geophysical fluid dynamics, might be of specific interest for studying the earth’s atmosphere.

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Dalrymple, Robert A., e James T. Kirby. "Models for very wide-angle water waves and wave diffraction". Journal of Fluid Mechanics 192 (luglio 1988): 33–50. http://dx.doi.org/10.1017/s0022112088001776.

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For a bathymetry consisting of parallel bottom contours, wide-angle parabolic models are developed to describe the diffraction of linear water waves. The first model, developed by operator correspondence, extends the validity of conventional forms of the parabolic model for wave angles up to 70° from the assumed wave direction. Through the use of Fourier decomposition, wave models valid to 90° are developed for three different lateral boundary conditions. By application, it is shown that the diffraction of waves through gaps or around structures is governed by the initial wave condition at the structure, which can be expanded into progressive and evanescent wave modes. Away from the structure, the wave field consists of only the progressive wave modes, which disperse according to their direction of propagation, the water depth and Snell's Law. Examples are shown for oblique waves through a gap, directional seas past a breakwater, a plane wave with varying crest amplitude, and finally for the diffraction of waves into a channel.

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Geller, Marvin A., Tiehan Zhou, Reto Ruedy, Igor Aleinov, Larissa Nazarenko, Nikolai L. Tausnev, Shan Sun, Maxwell Kelley e Ye Cheng. "New Gravity Wave Treatments for GISS Climate Models". Journal of Climate 24, n. 15 (1 agosto 2011): 3989–4002. http://dx.doi.org/10.1175/2011jcli4013.1.

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Abstract Previous versions of GISS climate models have either used formulations of Rayleigh drag to represent unresolved gravity wave interactions with the model-resolved flow or have included a rather complicated treatment of unresolved gravity waves that, while being climate interactive, involved the specification of a relatively large number of parameters that were not well constrained by observations and also was computationally very expensive. Here, the authors introduce a relatively simple and computationally efficient specification of unresolved orographic and nonorographic gravity waves and their interaction with the resolved flow. Comparisons of the GISS model winds and temperatures with no gravity wave parameterization; with only orographic gravity wave parameterization; and with both orographic and nonorographic gravity wave parameterizations are shown to illustrate how the zonal mean winds and temperatures converge toward observations. The authors also show that the specifications of orographic and nonorographic gravity waves must be different in the Northern and Southern Hemispheres. Then results are presented where the nonorographic gravity wave sources are specified to represent sources from convection in the intertropical convergence zone and spontaneous emission from jet imbalances. Finally, a strategy to include these effects in a climate-dependent manner is suggested.

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Pruser, H. H., H. Schaper e W. Zielke. "IRREGULAR WAVE TRANSFORMATION IN A BOUSSINESO WAVE MODEL". Coastal Engineering Proceedings 1, n. 20 (29 gennaio 1986): 205. http://dx.doi.org/10.9753/icce.v20.205.

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Numerical wave models for shallow water waves are of particular importance for the calculation of the wave climate in harbours and coastal areas. Especially nonlinear time domain models, which are based on the Boussinesq-Wave- Equations, may be helpful in the future for simulating the interaction of currents with refraction, diffraction, reflection and for simulating shoaling..-of irregular waves in natural areas; a potential which has not yet been fully developed. During the last ten years numerical models, based on these equations, have been published; such as ABBOTT et. al. , HAUGUEL and SCHAPER / ZIELKE . Research on this topic is currently being carried on. Some efforts have been made to verify the capability of the models to describe the various physical phenomena. However, up to now, verification has been limited to regular waves. The aim of this paper therefore is, to consider questions concerning irregular, nonlinear waves.

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Ito, Masahiro, e Yoshito Tsuchiya. "REPRODUCTION MODELS OF BEACH CHANGE BY STORM WAVES". Coastal Engineering Proceedings 1, n. 21 (29 gennaio 1988): 115. http://dx.doi.org/10.9753/icce.v21.115.

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This paper presents a technique to reproduce, by a twodimensional moveable-bed model, beach change due to the timedependent storm waves which are generated by the passage of an atmospheric depression. In the model test, scaling conditions for sand grain-size, vertical and horizontal lengths, and wave height and period characteristics were established by applying the authors' scale-model relationship which was reported; and wave duration time also was decided. A method of employing regular waves in the model to represent irregular waves in the field is proposed. From the results, it was shown that the model can reproduce well the beach change in the field using the regular waves having the mean wave properties in the irregular waves.

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Kichenassamy, Satyanad. "Existence of solitary waves for water-wave models". Nonlinearity 10, n. 1 (1 gennaio 1997): 133–51. http://dx.doi.org/10.1088/0951-7715/10/1/009.

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Niedzwecki, John M., Eric W. Sandt e Oriol R. Rijken. "Slepian models for waves and wave-structure interaction". Engineering Structures 17, n. 10 (dicembre 1995): 696–704. http://dx.doi.org/10.1016/0141-0296(95)00060-k.

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Tesi sul tema "Wave models"

Gidel, Floriane Marie Pauline. "Variational water-wave models and pyramidal freak waves". Thesis, University of Leeds, 2018. http://etheses.whiterose.ac.uk/21730/.

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A little-known fact is that, every week, two ships weighing over 100 tonnes sink in oceans, sometimes with tragic consequences. This alarming observation suggests that maritime structures may be struck by stronger waves than those they were designed to withstand. These are the legendary rogue (or freak) waves, i.e., suddenly appearing huge waves that have traumatised mariners for centuries and currently remain an unavoidable threat to ships, and to their crews and passengers. Thus motivated, an EU-funded collaboration between the Department of Applied Mathematics (Leeds University) and the Maritime Research Institute Netherlands (MARIN) supported this project, in which the ultimate goal, of importance to the international maritime sector, is to develop reliable damage-prediction tools, leading to beneficial impact in terms of both safety and costs. To understand the behaviour of rogue waves, cost-effective water-wave models are derived in both deep and shallow water. Novel mathematical and numerical strategies are introduced to capture the dynamic air-water interface and to ensure conservation of important properties. Specifically, advanced variational Galerkin finite-element methods are used to provide stable simulations of potential-flow water waves in a basin with wavemakers and seabed topography, which allows reliable simulations of rogue waves in a target area. For optimised computational speed, wave absorption is considered with a beach on which waves break and dissipate energy. Robust integrators are therefore introduced to couple the potential-flow model to shallow-water wave dynamics at the beach. Experimental validation of the numerical tank is conducted at Delft University of Technology to ensure accuracy of the simulations from the wavemaker to the beach. The numerical tank is designed for subsequent use by MARIN to investigate the damage caused by rogue waves on structures in order to update maritime design practice and to ensure safety of ships, therefore leading to a competitive commercial advantage across Europe.

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Yildirim, Baran. "Acoustic Wave Analysis Using Different Wave Propagation Models". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609527/index.pdf.

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In this study in order to simulate the acoustic waves, Ray Theory and Normal Mode models are used. These methods are analyzed using MATLAB simulation tool
differences between two models are examined and a region with a known bottom profile and sound velocity profiles is investigated. The Ray Theory is used in acoustic systems which is the one of the applications of wave modeling. Ray theory is solved with standard Ordinary Differential Equation solvers and normal mode with finite element method. Different bottom profiles and sound velocity profiles previously taken are interpolated to form an environment and examined in the case study. in the case study.

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Mei, Zhongtao. "Wave Functions of Integrable Models". University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1530880774625297.

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Du, Chenguang. "How Well Can Two-Wave Models Recover the Three-Wave Second Order Latent Model Parameters?" Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/103856.

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Although previous studies on structural equation modeling (SEM) have indicated that the second-order latent growth model (SOLGM) is a more appropriate approach to longitudinal intervention effects, its application still requires researchers to collect at least three-wave data (e.g. randomized pretest, posttest, and follow-up design). However, in some circumstances, researchers can only collect two-wave data for resource limitations. With only two-wave data, the SOLGM can not be identified and researchers often choose alternative SEM models to fit two-wave data. Recent studies show that the two-wave longitudinal common factor model (2W-LCFM) and latent change score model (2W-LCSM) can perform well for comparing latent change between groups. However, there still lacks empirical evidence about how accurately these two-wave models can estimate the group effects of latent change obtained by three-wave SOLGM (3W-SOLGM). The main purpose of this dissertation, therefore, is trying to examine to what extent the fixed effects of the tree-wave SOLGM can be recovered from the parameter estimates of the two-wave LCFM and LCSM given different simulation conditions. Fundamentally, the supplementary study (study 2) using three-wave LCFM was established to help justify the logistics of different model comparisons in our main study (study 1). The data generating model in both studies is 3W-SOLGM and there are in total 5 simulation factors (sample size, group differences in intercept and slope, the covariance between the slope and intercept, size of time-specific residual, change the pattern of time-specific residual). Three main types of evaluation indices were used to assess the quality of estimation (bias/relative bias, standard error, and power/type I error rate). The results in the supplementary study show that the performance of 3W-LCFM and 3W-LCSM are equivalent, which further justifies the different models' comparison in the main study. The point estimates for the fixed effect parameters obtained from the two-wave models are unbiased or identical to the ones from the three-wave model. However, using two-wave models could reduce the estimation precision and statistical power when the time-specific residual variance is large and changing pattern is heteroscedastic (non-constant). Finally, two real datasets were used to illustrate the simulation results
Doctor of Philosophy
To collect and analyze the longitudinal data is a very important approach to understand the phenomenon of development in the real world. Ideally, researchers who are interested in using a longitudinal framework would prefer collecting data at more than two points in time because it can provide a deeper understanding of the developmental processes. However, in real scenarios, data may only be collected at two-time points. With only two-wave data, the second-order latent growth model (SOLGM) could not be used. The current dissertation compared the performance of two-wave models (longitudinal common factor model and latent change score model) with the three-wave SOLGM in order to better understand how the estimation quality of two-wave models could be comparable to the tree-wave model. The results show that on average, the estimation from two-wave models is identical to the ones from the three-wave model. So in real data analysis with only one sample, the point estimate by two-wave models should be very closed to that of the three-wave model. But this estimation may not be as accurate as it is obtained by the three-wave model when the latent variable has large variability in the first or last time point. This latent variable is more likely to exist as a statelike construct in the real world. Therefore, the current study could provide a reference framework for substantial researchers who could only have access to two-wave data but are still interested in estimating the growth effect that supposed to obtain by three-wave SOLGM.

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Hill, David J. Saffman P. G. Saffman P. G. "Part I. Vortex dynamics in wake models. : Part II. Wave generation /". Diss., Pasadena, Calif. : California Institute of Technology, 1998. http://resolver.caltech.edu/CaltechETD:etd-04052007-141032.

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Murray, Stuart William. "Wave radiation in simple geophysical models". Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7922.

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Wave radiation is an important process in many geophysical flows. In particular, it is by wave radiation that flows may adjust to a state for which the dynamics is slow. Such a state is described as “balanced”, meaning there is an approximate balance between the Coriolis force and horizontal pressure gradients, and between buoyancy and vertical pressure gradients. In this thesis, wave radiation processes relevant to these enormously complex flows are studied through the use of some highly simplified models, and a parallel aim is to develop accurate numerical techniques for doing so. This thesis is divided into three main parts. 1. We consider accurate numerical boundary conditions for various equations which support wave radiation to infinity. Particular attention is given to discretely non-reflecting boundary conditions, which are derived directly from a discretised scheme. Such a boundary condition is studied in the case of the 1-d Klein-Gordon equation. The limitations concerning the practical implementation of this scheme are explored and some possible improvements are suggested. A stability analysis is developed which yields a simple stability criterion that is useful when tuning the boundary condition. The practical use of higher-order boundary conditions for the 2-d shallow water equations is also explored; the accuracy of such a method is assessed when combined with a particular interior scheme, and an analysis based on matrix pseudospectra reveals something of the stability of such a method. 2. Large-scale atmospheric and oceanic flows are examples of systems with a wide timescale separation, determined by a small parameter. In addition they both undergo constant random forcing. The five component Lorenz-Krishnamurthy system is a system with a timescale separation controlled by a small parameter, and we employ it as a model of the forced ocean by further adding a random forcing of the slow variables, and introduce wave radiation to infinity by the addition of a dispersive PDE. The dynamics are reduced by deriving balance relations, and numerical experiments are used to assess the effects of energy radiation by fast waves. 3. We study quasimodes, which demonstrate the existence of associated Landau poles of a system. In this thesis, we consider a simple model of wave radiation that exhibits quasimodes, that allows us to derive some explicit analytical results, as opposed to physically realistic geophysical fluid systems for which such results are often unavailable, necessitating recourse to numerical techniques. The growth rates obtained for this system, which is an extension of one considered by Lamb, are confirmed using numerical experiments.

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Timmermans, Ben. "Uncertainty in numerical wind-wave models". Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/378996/.

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The modelling of ocean waves is now carried out routinely at meteorological centres around the world. However, little is know about the source of the uncertainty in the predictions of waves produced, and sources can be numerous depending on the specific application. Historically it was felt that the dominant source of uncertainty originated from incomplete knowledge and expression of forcing winds. However more recent studies have focused on the underlying physical processes and their representations, with some authors questioning whether the limitation of the current modelling approach has been reached. Recently, methods for the statistical analysis of complex computer models, including models such as those used for wave prediction, have been developed. In this thesis these methods are applied to perform the first ever uncertainty analysis of a wave model. These new methods are applied to the state of the art wave model Wavewatch IIIr. This thesis principally explores the effect of tuning parameter uncertainty relating to the “Tolman and Chalikov” input and dissipation parameterisation, the discrete interaction approximation scheme for nonlinear wave-wave interactions and uncertainty about wind forcing, on wave simulation output, in a range of idealised cases, and realistically on Lake Michigan. The effectiveness of the statistical methods is first demonstrated in simple cases, before analysis is performed for progressively more complex simulations. In each case, uncertainty measures are computed with respect to simulation output in terms of summary wave statistics, typically including significant wave height and peak period. The analysis reveals nonlinear response and the relative importance of the various input, which in turn shows the active physical processes, and where the greatest sources of uncertainty lie. Both uncertainty about wind forcing and the process of nonlinear wave-wave interactions are found to be dominant in all cases, although energy dissipation is important in growing sea states. Finally, observational wave height data is used to perform a parameter calibration for simulations of stormy conditions on Lake Michigan, leading to improved performance.

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Clavica, Francesco. "Computational and experimental time domain, one dimensional models of air wave propagation in human airways". Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/9622.

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The scientific literature on airflow in the respiratory system is usually associated with rigid ducts. Many studies have been conducted in the frequency domain to assess respiratory system mechanics. Time-domain analyses appear more independent from the hypotheses of periodicity, required by frequency analysis, providing data that are simpler to interpret since features can be easily associated to time. However, the complexity of the bronchial tree makes 3-D simulations too expensive computationally, limiting the analysis to few generations. 1-D modelling in space-time variables has been extensively applied to simulate blood pressure and flow waveforms in arteries, providing a good compromise between accuracy and computational cost. This work represents the first attempt to apply this formulation to study pulse waveforms in the human bronchial tree. Experiments have been carried out, in this work, to validate the model capabilities in modelling pressure and velocity waveforms when air pulses propagate in flexible tubes with different mechanical and geometrical properties. The experiments have shown that the arrival of reflected air waves occurs in correspondence of the theoretical timing once the wave speed is known. Reflected backward compression waves have generated an increase of pressure (P) and decrease of velocity (U) while expansion backward waves have produced a decrease of P and increase of U according to the linear analysis of wave reflections. The experiments have demonstrated also the capabilities of Wave intensity analysis (WIA), an analytical technique used to study wave propagation in cardiovascular system, in separating forward and backward components of pressure and velocity also for the air case. After validating the 1-D modelling in space and time variables, several models for human airways have been considered starting from simplified versions (bifurcation trachea- main bronchi, series of tubes) to more complex systems up to seven generations of bifurcations according to both symmetrical and asymmetrical models. Calculated pressures waveforms in trachea are shown to change accordingly to both peripheral resistance and compliance variations, suggesting a possible non-invasive assessment of peripheral conditions. A favourable comparison with typical pressure and flow waveforms from impulse oscillometry system, which has recently been introduced as a clinical diagnostic technique, is also shown. The results suggested that a deeper investigation of the mechanisms underlying air wave propagation in lungs could be a useful tool to better understand the differences between normal and pathologic conditions and how pathologies may affect the pattern of pressure and velocity waveforms.

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Alves, Jose Henrique Gomes de Mattos Mathematics UNSW. "A Saturation-Dependent Dissipation Source Function for Wind-Wave Modelling Applications". Awarded by:University of New South Wales. Mathematics, 2000. http://handle.unsw.edu.au/1959.4/17786.

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This study reports on a new formulation of the spectral dissipation source term Sds for wind-wave modelling applications. This new form of Sds features a nonlinear dependence on the local wave spectrum, expressed in terms of the azimuthally integrated saturation parameter B(k)=k^4 F(k). The basic form of this saturation-dependent Sds is based on a new framework for the onset of deep-water wave breaking due to the nonlinear modulation of wave groups. The new form of Sds is succesfully validated through numerical experiments that include exact nonlinear computations of fetch-limited wind-wave evolution and hindcasts of two-dimensional wave fields made with an operational wind-wave model. The newly-proposed form of Sds generates integral spectral parameters that agree more closely with observations when compared to other dissipation source terms used in state-of-the-art wind-wave models. It also provides more flexibility in controlling properties of the wave spectrum within the high wavenumber range. Tests using a variety of wind speeds, three commonly-used wind input source functions and two alternative full-development evolution limits further demonstrate the robustness and flexibility of the new saturation-dependent dissipation source term. Finally, improved wave hindcasts obtained with an implementation of the new form of Sds in a version of the WAM model demonstrate its potential usefulness in operational wind-wave forecasting applications.

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Poon, Chun-Kin, e 潘俊健. "Numerical simulation of coupled long wave-short wave system with a mismatch in group velocities". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B35381334.

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Libri sul tema "Wave models"

Kashchenko, Serguey. Models of Wave Memory. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-19866-8.

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Jeng, Dong-Sheng. Porous Models for Wave-seabed Interactions. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013.

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Piechna, Janusz. Wave machines, models, and numerical simulation. Warszawa: Oficyna Wydawnicza Politechniki Warszawskiej, 2005.

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Jeng, Dong-Sheng. Porous Models for Wave-seabed Interactions. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-33593-8.

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Leeuwen, P. J. van. Low frequency wave generation due to breaking wind waves. [Delft]: Faculty of Civil Engineering, Delft University of Technology, 1992.

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(Firm), Knovel, a cura di. Waves and wave forces on coastal and ocean structures. Hackensack, N.J: World Scientific, 2006.

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Berezin, I︠U︡ A. Modelling non-linear wave processes. Utrecht, The Netherlands: VNU Science Press, 1987.

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Suttles, John T. Angular radiation models for earth-atmosphere system. Hampton, Va: Langley Research Center, 1988.

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Guinot, Vincent. Wave propagation in fluids: Models and numerical techniques. Hoboken, NJ: ISTE/Wiley, 2008.

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Guinot, Vincent. Wave propagation in fluids: Models and numerical techniques. 2^a ed. London: ISTE, 2010.

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Capitoli di libri sul tema "Wave models"

Sandev, Trifce, e Živorad Tomovski. "Fractional Wave Equations". In Fractional Equations and Models, 213–45. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-29614-8_5.

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Ebert, Marcelo R., e Michael Reissig. "Semilinear Classical Wave Models". In Methods for Partial Differential Equations, 351–65. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-66456-9_20.

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Khandekar, M. L. "Wave Prediction: Spectral Models". In Operational Analysis and Prediction of Ocean Wind Waves, 68–103. New York, NY: Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4613-8952-1_5.

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Khandekar, M. L. "Validation of Wave Models". In Operational Analysis and Prediction of Ocean Wind Waves, 127–64. New York, NY: Springer New York, 1989. http://dx.doi.org/10.1007/978-1-4613-8952-1_7.

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Buldakov, Eugeny. "Wave Propagation Models for Numerical Wave Tanks". In Advanced Numerical Modelling of Wave Structure Interactions, 36–68. First edition. 1 Boca Raton, FL : CRC Press/Taylor & Francis: CRC Press, 2020. http://dx.doi.org/10.1201/9781351119542-2.

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Tanguy, Jean-Michel, Jean-Michel Lefèvre e Philippe Sergent. "Wave Generation and Coastal Current Models". In Mathematical Models, 235–333. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118557853.ch8.

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Doyle, James F. "Higher Order Waveguide Models". In Wave Propagation in Structures, 123–83. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-59679-8_5.

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Van Groesen, E. "Wave groups in uni-directional surface-wave models". In Floating, Flowing, Flying, 215–26. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-1564-5_13.

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Glazman, Roman E. "Scale-Dependent Ocean Wave Turbulence". In Stochastic Models in Geosystems, 97–114. New York, NY: Springer New York, 1997. http://dx.doi.org/10.1007/978-1-4613-8500-4_5.

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Ockendon, Hilary, e John R. Ockendon. "Models for Linear Wave Propagation". In Texts in Applied Mathematics, 23–57. New York, NY: Springer New York, 2015. http://dx.doi.org/10.1007/978-1-4939-3381-5_3.

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Atti di convegni sul tema "Wave models"

Yeh, Harry, Philip Liu e Costas Synolakis. "Long-Wave Runup Models". In Second International Workshop on Long-Wave Runup Models. WORLD SCIENTIFIC, 1997. http://dx.doi.org/10.1142/9789814530330.

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Hanyga, Andrzej. "Fractional diffusion and wave equations". In Mathematical Models and Methods for Smart Materials. WORLD SCIENTIFIC, 2002. http://dx.doi.org/10.1142/9789812776273_0017.

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Nagy, Lajos, Zoltan Sandor, Zoltan Szabo e Tamas Csaba. "Urban Wave Propagation Models". In 26th European Microwave Conference, 1996. IEEE, 1996. http://dx.doi.org/10.1109/euma.1996.337581.

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Pákozdi, Csaba, Silas Spence, Sebastien Fouques, Maxime Thys, Hagbart S. Alsos, Erin E. Bachynski, Hans Bihs e Arun Kamath. "Nonlinear Wave Load Models for Extra Large Monopiles". In ASME 2018 1st International Offshore Wind Technical Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/iowtc2018-1083.

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Abstract (sommario):

As the offshore wind industry moves toward deeper water, with larger turbines and correspondingly larger monopile foundations, nonlinear loads from steep waves may become more important for the ULS design. Nonlinear numerical wave tanks (NWTs) for generating wave kinematics, to be used as input to i.e. Morison’s equation, have been applied by several research groups, but further validation of the obtained wave kinematics is needed. Furthermore, the load models for larger diameters also need to be evaluated. The present work first compares the wave elevation results from existing two-dimensional (2D) NWT tools. The nonlinear wave elevation is compared to experimental results from model tests of two regular waves. Several methods of wave generation are considered. The conclusion from the study is that the selected codes represent physics well, even though we see individual differences, which are discussed. Differences between codes are not necessarily only due to differences in the applied theory, but also modeling of wave flap, numerical beach etc. Load (and response) estimates from using the NWT kinematics combined with the Morison load model are compared to experimental results, two sets of CFD simulations, and to simpler load models. Alternative methods of selecting the load coefficients for the simplified load models are also discussed.

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Craig, Walter, Philippe Guyenne e Henrik Kalisch. "Hamiltonian Formulation and Long Wave Models for Internal Waves". In ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2007. http://dx.doi.org/10.1115/omae2007-29314.

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We derive a Hamiltonian formulation of the problem of a dynamic free interface (with rigid lid upper boundary conditions), and of a free interface coupled with a free surface, this latter situation occurring more commonly in experiment and in nature. Based on the linearized equations, we highlight the discrepancies between the cases of rigid lid and free surface upper boundary conditions, which in some circumstances can be significant. We also derive systems of nonlinear dispersive long wave equations in the large amplitude regime, and compute solitary wave solutions of these equations.

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Dallinga, R. P., e G. J. Feikema. "Wave Models In Ship Design". In Seakeeping and Weather. RINA, 1995. http://dx.doi.org/10.3940/rina.seak.1995.17.

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Seiffert, Betsy R., e Guillaume Ducrozet. "A Comparative Study of Wave Breaking Models in a High-Order Spectral Model". In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61664.

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We examine the implementation of two different wave breaking models into the nonlinear potential flow solver HOS-NWT. HOS-NWT is a computationally efficient, open source code that solves for surface elevation in a numerical wave tank using the High-Order Spectral (HOS) method [1]. The first model is a combination of a kinematic wave breaking onset criteria proposed by Barthelemey, et al. [2] and validated by Saket, et al. [3], and an energy dissipation mechanism proposed by Tian, et al. [4, 5]. The wave breaking onset parameter is based on the ratio of local energy flux velocity to the local crest velocity. Once breaking is initiated, an eddy viscosity parameter is estimated based on the pre-breaking local wave geometry, as described in [4, 5]. This eddy viscosity is then added as a diffusion term to the kinematic and dynamic free surface boundary conditions for the duration of wave breaking. Results implementing this wave breaking mechanism in HOS-NWT have shown that the model can successfully calculate the surface elevation and corresponding frequency spectra, as well as the energy dissipation associated with breaking waves [6–8]. The second model implemented to account for wave breaking in HOS-NWT is based on the method proposed by Chalikov, et al. [9–11]. This model defines wave breaking onset by the curvature of the water surface and defines the wave as broken if it exceeds a certain value. A diffusion term is added to the kinematic and dynamic free surface boundary conditions which dissipates energy based on the local curvature of the water surface, which is consequently not constant in space nor time. Calculations made using the two models are compared with large scale experimental measurements conducted at the Hydrodynamics, Energetics and Atmospheric Environment Lab (LHEEA) at Ecole Centrale de Nantes. Comparison of calculations with measurements suggest that both models are successful at predicting wave breaking onset and energy dissipation. However, the model proposed by Barthelemy, et al. [2] and Tian, et al. [4] can be applied without knowing anything about the breaking waves a priori, whereas the model proposed by Chalikov [9] requires tuning to specific conditions.

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Caˆndido, Jose´, Henrique Oliveira Pires e M. Teresa Pontes. "Verification of 2D Wave Spectra Produced by Wave Models". In ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2004. http://dx.doi.org/10.1115/omae2004-51368.

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In this paper a methodology for assessing the accuracy of full directional wave spectra produced by wind-wave models is presented and tested. This methodology includes graphical and parametric comparisons of model directional spectra against data obtained from directional buoys. Results of the verification of 3rd generation wind-wave models using directional buoy data show that in general the accuracy of model directional results is good. In addition it was found that this methodology is well suited to identify the occurrence of different wave systems in the same sea state, namely swells within the same frequency band but with different origins.

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Brandini, Carlo, e Stéphan T. Grilli. "Three-Dimensional Wave Focusing in Fully Nonlinear Wave Models". In Fourth International Symposium on Ocean Wave Measurement and Analysis. Reston, VA: American Society of Civil Engineers, 2002. http://dx.doi.org/10.1061/40604(273)112.

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Vledder, Gerbrant Ph van, Thomas H. C. Herbers, Robert J. Jensen, Don T. Resio e Barbara Tracy. "Modelling of Non-Linear Quadruplet Wave-Wave Interactions in Operational Wave Models". In 27th International Conference on Coastal Engineering (ICCE). Reston, VA: American Society of Civil Engineers, 2001. http://dx.doi.org/10.1061/40549(276)62.

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Rapporti di organizzazioni sul tema "Wave models"

Camassa, R., W. Choi, D. D. Holm, C. D. Levermore e Y. Lvov. Dispersive internal long wave models. Office of Scientific and Technical Information (OSTI), novembre 1998. http://dx.doi.org/10.2172/674984.

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Venakides, S., M. A. Haider e V. Papanicolaou. Wave Propagation in Photonic Crystal Models. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2000. http://dx.doi.org/10.21236/ada392989.

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Stevens, J. L., D. A. Adams, M. G. Eneva e G. B. Baker. Improved Surface Wave Dispersion Models and Amplitude Measurements. Fort Belvoir, VA: Defense Technical Information Center, ottobre 2003. http://dx.doi.org/10.21236/ada422916.

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Walker, David T. SAR Assimilation for Near-Shore Spectral Wave Models. Fort Belvoir, VA: Defense Technical Information Center, settembre 2003. http://dx.doi.org/10.21236/ada620256.

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Rogers, W. E., James M. Kaihatu e Y. L. Hsu. Review and Verification of Numerical Wave Models for Near Coastal Areas - Part 2: Verification of Near Coastal Numerical Wave Models. Fort Belvoir, VA: Defense Technical Information Center, gennaio 1998. http://dx.doi.org/10.21236/ada339125.

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Vledder, Gerbrant Ph Van. Improved Parameterizations of Nonlinear Four Wave Interactions for Application In Operational Wave Prediction Models. Fort Belvoir, VA: Defense Technical Information Center, settembre 1999. http://dx.doi.org/10.21236/ada613278.

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Ketcham, Stephen A., Minh Q. Phan, Richard S. Darling e Mihan H. McKenna. Realization of State-Space Models for Wave Propagation Simulations. Fort Belvoir, VA: Defense Technical Information Center, gennaio 2012. http://dx.doi.org/10.21236/ada563924.

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Bratos, Steven M. Comparison Between Third- and Second-Generation Ocean Wave Models. Fort Belvoir, VA: Defense Technical Information Center, settembre 1998. http://dx.doi.org/10.21236/ada353603.

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Yang, Zhaoqing, Wei-Cheng Wu e Taiping Wang. Model Test Bed for Evaluating Unstructured-Grid Wave Models for Resource Assessment and Characterization. Office of Scientific and Technical Information (OSTI), ottobre 2017. http://dx.doi.org/10.2172/1630729.

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Stevens, Jeffry L., David A. Adams, G. E. Baker, Mariana G. Eneva e Heming Xu. Improved Surface Wave Dispersion Models, Amplitude Measurements and Azimuth Estimates. Fort Belvoir, VA: Defense Technical Information Center, marzo 2005. http://dx.doi.org/10.21236/ada438946.

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