Eugenio Pugliese Carratelli

Marina di Rimini is located on the western shore of the Northern Adriatic. The marina itself provides berthing for pleasure craft, and is accessed through a river channel which is trained several hundred metres into the sea. This layout is common along the Northern Adriatic coastline of Italy. On occasion, however, navigation along the river channel into the marina basin is thwarted by excess levels of wave disturbance. It has been proposed to modify the layout of the river training walls so that greater protection from waves, and therefore safer navigation into the marina, is achieved. The objective of the study reported in this paper was to examine the potential impact on the nearby shoreline of modifying the layout of the river training walls. Numerical models exploit our understanding of physical processes and it has become a standard requirement, in turn, to exploit numerical models when carrying out assessments of the effects of intervening at the coastline. The innovative met...

Liquid impact on planar surfaces is a challenging issue in many research fields. Under certain circumstances, these phenomena may occasionally produce high, spatially localized pressure peaks, thus inducing dangerous solicitations. The present work focuses on some relevant computational aspects of the fluid impact onto inclined planar surface, making use of the Weakly Compressible Smoothed Particle Hydrodynamics (WCSPH) Lagrangian technique. With reference to the early stages of the impact process, pressure distribution is described as function of the incident wave’s features and the angle of incidence of the solid surface assumed. Results are then discussed and compared with the corresponding ones obtained via Eulerian software. Key-Words: SPH, WCSPH, FSI, Slamming loads, Numerical methods in fluids

The design of breakwaters must be based on the full understanding of the interaction of a complex natural system (the sea and shores) with artificial structures (breakwaters). Typically, design work entails extensive physical modeling, which can be quite expensive and time-consuming. Until recently, the complex aspects of breakwater behavior were considered too challenging for detailed numerical simulations. This is especially the case for breakwaters consisting of rubble mounds composed of blocks of concrete or rocks in which water flows through complex paths with unsteady motion. Within this context, the problems induced by the rock mound have so far been treated by the sometimes simplistic “porous media” approach which assumes a filtration flow (Darcy or Forchheimer for a linear or quadratic loss, respectively) between the blocks

Satellite altimeter data provide useful information about short term oscillations of storm intensity, a phenomenon which might bear a relevant effect on the estimation of extreme value SWH. However, while such data are now easily and readily available, their application is not at all straightforward: problems like the size of the sampled area, the presence of rain and the influence of land or floating objects, may confuse the results and have to be taken into account. The paper and the discussion will deal with recent research in this field and will provide results on gustiness effects as estimated from both satellite data and wave meter measurement.

Altimeter data have been routinely assimilated and used to assess the reliability of wave forecasts for many years. A more recent application of such data is to provide an indication of Small Scale Storm Variability (SSSV) due to the irregular wind structure at the sea level (“gustiness”). Both gustiness and SSSV have been examined by using Jason - 1, Jason - 2 and ESA Envisat altimeter SWH data along passes in enclosed seas. Statistical parameters have been extracted and compared with similar statistics from state-of-the-art Meteo/Wave models. A variability is shown to exist on a scale as low as the resolution of altimeter data - i.e. down to a few kilometres - while weather and wave models - even those with the highest resolution - show a much smoother behaviour

Until recently, physical models were the only way to investigate into the details of breakwaters behavior under wave attack. From the numerical point of view, the complexity of the fluid dynamic processes involved has so far hindered the direct application of Navier-Stokes equations within the armour blocks, due to the complex geometry and the presence of strongly non stationary flows, free boundaries and turbulence. In the present work the most recent CFD technology is used to provide a new and more reliable approach to the design analysis of breakwaters, especially in connection with run-up and reflection. The solid structure is simulated within the numerical domain by overlapping individual virtual elements to form the empty spaces delimited by the blocks. Thus, by defining a fine computational grid, an adequate number of nodes is located within the interstices and a complete solution of the full hydrodynamic equations is carried out. In the work presented here the numerical simu...

From the numerical point of view, the complexity of the fluid dynamic processes involved has so far hindered the direct application of Navier-Stokes equations within the armour blocks, due to the complex geometry and the presence of strongly non stationary flows, free boundaries and turbulence. In the present work the most recent CFD technology is used to provide a new and more reliable approach to the design analysis of breakwaters, especially in connection with run-up and overtopping.

Calculating the significant wave height (SWH) in a given location as a function of the return time is an essential tool of coastal and ocean engineering; such a calculation can be carried out by making use of the now widely available weather and wave model chains, which often lead to underestimating the results, or by means of in situ experimental data (mostly, wave buoys), which are only available in a limited number of sites. A procedure is hereby tested whereby the curves of extreme SWH as a function of the return time deriving from model data are integrated with the similar curves computed from buoy data. A considerable improvement in accuracy is gained by making use of this integrated procedure in all locations where buoy data series are not available or are not long enough for a correct estimation. A useful and general design tool has therefore been provided to derive the extreme value SWH for any point in a given area.

The orbital velocity of sea wave particles affects the value of sea surface parameters as measured by radar Doppler altimeters (also known as delay Doppler altimeter (DDA)). In DDA systems, the along-track resolution is attained by algorithms that take into account the Doppler shift induced by the component along the Earth/antenna direction of the satellite velocity, VS. Since the vertical component of the wave particle orbital velocity also induces an additional Doppler effect (in the following R-effect), an error arises on the positioning of the target on the sea surface. A numerical investigation shows that when the wavelength of sea waves is of the same order of magnitude of the altimeter resolution, the shape of the waveform might be significantly influenced by the R-effect. The phenomenon can be particularly important for the monitoring of long swells, such as those that often take place in the oceans.

It has been shown before, and it is intuitively evident, that in a Significant Wave Height (SWH) time series, the longer the sampling interval, the lower is the number of events which are above a given threshold value. As a consequence, the use of data with a low time resolution (such as a 3 h sampling, for instance) causes a considerable undervaluation of the extreme SWH values for a given return time RT. In this paper an example of such a bias is provided, and a method is suggested to estimate it on a regional basis. Results may help to improve the use of historical wave meters data which were often collected with a low time resolution, and may also provide a tool to improve the application of Numerical Meteo-Wave models to the evaluation of extremes.

Extreme weather events have significant impacts on coastal human activities and related economy. In this scenario the forecast of sea storms and wave run-up events is a challenging goal to mitigate the wave effects on shores, piers and coastal structures. To do this, we used a computational model chain based on both community and ad hoc developed numerical models in an operational context to evaluate the beach inundation levels. At this aim, we compared the results of simulated and observed wave run-up levels on a micro-tidal beach located on the northern Tyrrhenian Sea. The offshore wave simulations have been performed by WaveWatch III model, implemented by Campania Center for Marine and Atmospheric Monitoring and Modelling (CCMMMA) – University of Naples Parthenope, which were used as initial conditions for run-up calculations using different formulas. The validation of the simulated waves was done with different observation systems. The offshore wave simulations were matche...

In the last few years, a number of land- and ship-based X-band radar systems have been developed to collect information on the sea state, i.e., on the significant wave height as well as on its spectral distribution. More recently, new techniques have been developed to estimate shallow water bathymetry, by taking into account the effects of depth on the dispersion of gravity waves. This chapter is aimed at reviewing such state-of-the-art algorithms and at providing some examples of applications of the most recent technique. It is shown that the accuracy is fairly adequate for shallow water, but it decreases significantly as the depth increases; besides, because the effects of stationary or nearly stationary currents interfere with the analysis, it is necessary to make use of algorithms that can estimate both depth and currents simultaneously.

In the present article a new procedure is proposed to study the interactions between maritime breakwaters (submerged or emerged) and the waves, by integrating CAD and CFD software. The approach is meant to match closely the physical laboratory test procedure, and it is oriented at analyzing the hydrodynamic aspects of the phenomenon (overtopping, breaking, run-up, reflection, transmission) and the stability of primary armour elements. Methodology and results

ABSTRACT Since no research on radar rainfall estimation was ever performed in Southern Italy, a research group was set up in order to produce and develop high resolution radar-rainfall data sets for the Campania Region. The group started its activity in the spring 1999 with a measurement campaign based on a meteorological radar located in the Italian Air Force base of Grazzanise (~ 20 km north of Naples) and a network of rain gauges located in a number of critical positions in Campania. The radar sensor is a Plessey 46 C with a RTX incoherent which supplies only horizontal reflectivity measurements. After a preliminary work phase aimed at removing or reducing noise from the radar images, a first implementation of the Marshall/Palmer relationship to the reflectivity data showed a reasonable agreement with the available rain gauge data. Further results on the spatial distributions of the rainfall cells are expected in the near future.

Until recently, physical models were the only way to investigate into the details of breakwaters behavior under wave attack. From the numerical point of view, the complexity of the fluid dynamic processes involved has so far hindered the direct application of Navier-Stokes equations within the armour blocks, due to the complex geometry and the presence of strongly non stationary flows, free boundaries and turbulence. In the present work the most recent CFD technology is used to provide a new and more reliable approach to the design analysis of breakwaters, especially in connection with run-up and overtopping. The solid structure is simulated within the numerical domain by overlapping individual virtual elements to form the empty spaces delimited by the blocks. Thus, by defining a fine computational grid, an adequate number of nodes is located within the interstices and a complete solution of the full hydrodynamic equations is carried out. In the work presented here the numerical sim...

The movement of floating pollutants such as oil slicks on the surface of the sea is due to a number different factors, among which wave drift is certainly significant.In principle, it has been known since Stokes' time that a floating particle is subject to the movement caused by the orbital motion of water particles and that an average drift velocity

A 50 sq m solar linear concentrator plant with cavity boilers has been realized in a brewery to evaluate the applicability of using solar energy to supply industrial process heat in the 120-300 C range. The aims of this plant include the experimental testing of a mathematical computer model to obtain a general computer code simulating the heat and mass transfer phenomena in the plant, measuring the plant and cavity boiler photothermal conversion efficiency, and solving the problems arising from the joining of the solar plant with the preexisting brewery water-steam network. Linear parabolic concentrators which track the sun were used, having mirrors with an 0.86 reflectivity; the plant is used to overheat pressurized water before entering the traditional boilers for vaporization. Preliminary experimental results indicate that thermal losses from the Cu pipes are strongly dependent on atmospheric conditions, necessitating the soldering of the pyrex glass and the Al-Fe boiler envelope.

ABSTRACT The effectiveness of natural circulation and ventilation systems based on the “solar chimneys” principle has been tested for a number of years at numerous sites, but thermal and fluid mechanical aspects of their operation need to be fully understood before conclusive results can be supplied; a long term research work has therefore been undertaken by the authors, including both experimentation in two test sites in Italy and numerical simulation.In the present paper the heat transfer equation for one dimensional laminar flow is numerically solved with the appropriate radiative boundary conditions.Temperature fields calculated in this way are then employed to evaluate air density variations and consequently the upward driving force available to overcome head losses in the air circulation.Optical plate spacing in steady state conditions appears to be strongly dependent on head losses occurring outside the collecting section and on winter or summer use of the system; it shows a softer dependence on incident solar energy fluxes.

Della Rocca, M.R., Carratelli, E.P.
A model for wind speed and wave height retrieval from radar altimeter measurements
2000  European Space Agency, (Special Publication) ESA SP

Source of the Document European Space Agency, (Special Publication) ESA SP (461), pp. 735-743
A numerical algorithm is here proposed to simulate the measurement of ocean wave height and wind speed by radar
altimeter. The algorithm takes into account a realistic ocean wave spectrum and employs a parametric sub-model to
simulate the electromagnetic waves scattering from the surface, thus providing greater flexibility and realism than the
analytical models currently used. The model is shown to be consistent even when different backscatter models are
employed, and numerical results prove that the measured value of the significant wave height does not depend upon the
wave period while - on the opposite - wind speed measurements are significantly affected by it.
The aim of this work is two-fold: on the one hand to provide a tool to improve the understanding and thus the accurate
calibration of altimeter data, and on the other hand to develop a model which could eventually be used to simulate the sea
state response as seen by the altimeter and by other microwave instruments.

C.C. Giarrusso , E.Pugliese Carratelli,  G. Spulsi
Solutions to Coastal Disasters 2002 San Diego 2002

The paper  reports on the experience gained by the Authors during the compilation of Civil Protection Contingency Plans for Italian Local and Watershed Authorities, as well as on the related research activities.
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The main task carried out in connection with such work was the drawing up of hazard maps for different time horizons (e.g. 3 and 10 years) and different damage levels;  the problem associated with both coastal erosion forecasting (which affects long term risks) and wave run-up (which determines short term risks and hazard levels) will be quickly reviewed with a strong emphasis on the operational application.  Thus no discussion will be provided about the relative efficiency of long-shore erosion models – about which a wealth of literature already exists – while some information will be provided about the use of laser altimetry, ortophoto imagery and conventional mapping techniques in providing data on the coastline position.

A special emphasis will be given on the techniques used to evaluate run up risk on low coasts, by comparing results given by standard formulae with those obtained by making use of 2D shallow water numerical models of waves;  details on model calibration techniques will be given and the connection between the model output and the potential damage to coastal infrastructure is discussed.

Italian legislation provides for hazardcontingency plans to be prepared by the regional,provincial and local authorities. Despite the extentof damage often caused on the Italian coasts by theaction of the sea, sea related hazards have so farbeen usually ignored; only recently a limited budgetin some provinces was allocated for the analysis ofrisks related to storm damage. The present paper reports on the proceduresand the techniques employed and tested within theframework of the provincial contingency plan onthe coast of the Salerno province in Italy (Figure 1). The work was mainly oriented to the evaluation ofthe potential damage that can be caused by the directaction of waves on coastal areas and on thepreparation of hazard maps. The methods and the datathat can be used to evaluate the risks are reviewed here,first by rapid examination of the wave fieldformation offshore and its transformation on shallowwater and then by considering the run-up on beachesand infrastructures; the paper is focussed inparticular on these latter problems, which – formsome point of view – are original and specific tocivil protection problems.

ABSTRACT A network of European organisations with interests in the utilisation of long sea outfalls as an integral element in the sewerage of coastal communities has recently been established. The central aim is to provide a focus both for the adoption of best practices and the identification of outstanding problem areas across the European community, against the background of the standards of practice demanded by the recent implementation of the European Commission's (EC) Urban Waste Water Treatment Directive. This article is intended both to inform a wider audience of the existence of the network and to extend the call for membership both to European parties and others interested in being informed on European developments in this area.

In recent years, the interest in developing new technologies to produce energy with low environmental impact by using renewable sources has grown exponentially all over the world. In this context, the experiences made to derive electricity from the sea (currents, waves, etc.) are of particular interest. At the moment, due to the many existing experiments completed or still in progress, it is quite impossible explain what has been obtained but it is worth mentioning the EMEC, which summarizes the major projects in the world. Another important environmental aspect, also related to the maritime field, is the coastal protection from the sea waves. Even in this field, since many years, the structural and non-structural solutions which can counteract this phenomenon are analyzed, in order to cause the least possible damage to the environment. The studies in development by the researchers of the University of Salerno are based on these two aspect previously presented. Considering the technologies currently available, a submerged system has been designed, WECPOS (Wave Energy Coastal Protection Oscillating System), to be located on relatively shallow depths, to can be used simultaneously for both electricity generation and for the coastal protection using the oscillating motion of the water particles. The single element constituting the system is realized by a fixed base and three movable panels that can fluctuate in a fixed angle. The waves interact with the panels generating an alternative motion which can be exploited to produce electricity. At the same time, the constraint movement imposed for the rotation of the panels is a barrier to the wave propagation phenomena, triggering the breaking in the downstream part of the device. So the wave energy will be dissipated obtaining a positive effect for the coastal protection. Currently, the efficiency and effectiveness of the system (WECPOS single module) has been studied by using numerical models. Using the FLOW-3D® software it has been possible to evaluate the hydrodynamic interactions that occur between a regular wave, with different height and period characteristics. The RANS equations, coupled with the RNG turbulence model, have been integrated on a three-dimensional channel (90.0 x 6.0 x 8.0 m), using a numerical domain made of two mesh blocks: a general one containing the entire domain (cells size 0.30 cm) and the localized one on the device (cells size 0.10 cm). With the results, by assessing the rotational angle, angular velocity, hydraulic torque of the individual panel it has been possible to estimate the potential energy production. A Matlab/Simulink model has been built to estimate the production of electric energy by means of an oleodynamic system consisting of a piston and a turbine coupled with an electric generator. About the coastal protection, by estimating some characteristic parameters of the wave motion (zero-moment wave height Hmo, transmission coefficient Kt and the average free surface elevation), the behaviour of the WECPOS device has been analyzed for its ability in wave energy dissipation.