1,721,168 research outputs found
A first attempt of analysis of coastal physical models by means of numerical model
No full textIt is commonly known that beach physical models are influenced by scale effects. Scale effects may be minimized by using large models. Nevertheless, since large models require costly facilities, it would be very important to individuate a method for the evaluation of scale effects. The main purpose of such method would be to re-scale the model results in order to reconstruct the prototype beach profile. Numerical beach profile models may be used in order to analyse the physical processes which regulate scale effects. In the present paper a first attempt in this direction is presented
Risalita di onde impulsive su piani inclinati
No full textLa stima della risalita (runup) di un fronte d’onda transitorio che si propaga sulla superficie libera di un corpo idrico è di fondamentale importanza per la sicurezza delle sponde dei bacini artificiali o delle aeree costiere potenzialmente interessate da tale fenomeno. Viene proposta una formula previsionale, basata su dati sperimentali originali, che fornisce la stima della risalita di onde impulsive su piani inclinati in funzione delle caratteristiche dell’onda incidente (altezza e periodo) e della configurazione geometrica (pendenza del piano inclinato e tirante idrico). E’ stato effettuato un confronto con le stime fornite da formule note in letteratura e si è trovato un buon accordo sia con quelle di origine sperimentale, sia con quelle di tipo teorico, con la differenza che quella proposta è applicabile alle diverse tipologie di perturbazioni e include, a differenza di quelle esistenti, il periodo della perturbazione tra le variabili indipendenti. Infine è stata applicata una teoria analitico–numerica non lineare allo scopo di confrontare la soluzione teorica con i risultati sperimentali
Ortorettifica di immagini satellitari ad alta risoluzione finalizzata al monitoraggio costiero a scala regionale
No full textNumerical and Physical Modeling of Ponte Liscione (Guardialfiera, Molise) Dam Spillways and Stilling Basin
Full text linkIssues such as the design or reauditing of dams due to the occurrence of extreme events caused by climatic change are mandatory to address to ensure the safety of territories. These topics may be tackled numerically with Computational Fluid Dynamics and experimentally with physical models. This paper describes the 1:60 Froude-scaled numerical model of the Liscione (Guardialfiera, Molise, Italy) dam spillway and the downstream stilling basin. The k-omega SST turbulence model was chosen to close the Reynolds-averaged Navier-Stokes equations (RANS) implemented in the commercial software Ansys Fluent(R). The computation domain was discretized using a grid with hexagonal meshes. Experimental data for model validation were gathered from the 1:60 scale physical model of the Liscione dam spillways and the downstream riverbed of the Biferno river built at the Laboratory of Hydraulic and Maritime Constructions of the Sapienza University of Rome. The model was scaled according to the Froude number and fully developed turbulent flow conditions were reproduced at the model scale (Re > 10,000). From the analysis of the results of both the physical and the numerical models, it is clear that the stilling basin is undersized and therefore insufficient to manage the energy content of the fluid output to the river, with a significant impact on the erodible downstream river bottom in terms of scour depths. Furthermore, the numerical model showed that a less vigorous jet-like flow is obtained by removing one of the sills the dam is supplied with
Laboratory Fish in Biomedical Research: Biology, Husbandry and Research Applications for Zebrafish, Medaka, Killifish, Cavefish, Stickleback, Goldfish and Danionella Translucida
No full textLaboratory investigation on wave overtopping of composite breakwaters: The port of civitavecchia case
No full textFeasibility of Tsunami Early Warning Systems for small volcanic islands
No full textThis paper investigates the feasibility of Tsunami Early Warning Systems for small volcanic islands focusing on warning of waves generated by landslides at the coast of the island itself. The critical concern is if there is enough time to spread the alarm once the system has recognized that a tsunami has been generated. We use the results of a large scale physical model experiment in order to estimate the time that tsunamis take to travel around the island inundating the coast. We discuss how and where it is convenient to place instruments for the measurement of the waves
Numerical and Physical Modeling of Ponte Liscione (Guardialfiera, Molise) Dam Spillways and Stilling Basin
No full textThe investigation of the safety conditions of hydraulic infrastructures such as dams is of great interest for safeguarding territories and assessing their risk level. Issues as design orverification ofstructures may be tackled numericallywith Computational Fluid Dynamics and experimentallywith physical models. This paper describes the 1:60 Froude scaled numerical model ofthe Liscione (Guardialfiera, Molise, Italy) dam spillway and the downstream stilling basin. The k-w SST turbulence model was chosen for closing the Reynolds Averaged Navier-Stokes equations (RANS). The computation domain was discretized using a grid with hexagonal meshes. Experimental data have been gathered from the 1:60 scale physical model ofthe Liscione dam spillways and the downstream riverbed ofthe Biferno river built at the Laboratory of Hydraulic and Maritime Constructions of Sapienza University of Rome. The model is scaled according to the Froude number and fully-developed turbulent flow conditions have been reproduced at the model scale (Re > 10,000). From the analysis ofthe results of both the physical and the numerical models it is certainly clear how the dissipation tank is undersized and therefore insufficient to manage the energy content ofthe current output to the river. As a consequence, the flow is introduced into the riverbed with a high energy content, which impacts on an erodible bottom
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