1,720,988 research outputs found
Studio del clima meteomarino e della diffusione dell’effluente dalla condotta sottomarina in progetto sul litorale di Manduria
Il Laboratorio di Ricerca e Sperimentazione per la Difesa Delle Coste - Politecnico Di Bari
Nearshore morphodynamic of a drained beach
The paper deals with a morphological study on a drained beach, under different wave conditions.
The Beach Drainage System (BDS) should artificially increase beach infiltration capacity by installing a drain under the beach face. The system produces a water table lowering and, consequently, an increasing of unsaturated zone (Damiani et Al.,2009); moreover, a vertical infiltration flow increases effective weight of grains, producing a better stability. According to the above hydrodynamic effect, BDS should influence cross-shore sediment transport in the shore zone.
Many BDS prototypes have been installed around the world; also in Italy, some examples are available, i.e. Ostia (Damiani et Al.,2003), Alassio and Procida (Vicinanza et Al.,2009). Field monitoring is very useful to assess the effectiveness of the system, even if with uncertainties in results, affected by the impossibility to control the boundary conditions. Laboratory tests (Damiani et Al.,2009) could be used in defining how does the system work in different wave conditions and drain configurations
Nearshore morphodynamic of a drained beach
The paper deals with a morphological study on a drained beach, under different wave conditions.
The Beach Drainage System (BDS) should artificially increase beach infiltration capacity by installing a drain under the beach face. The system produces a water table lowering and, consequently, an increasing of unsaturated zone (Damiani et Al.,2009); moreover, a vertical infiltration flow increases effective weight of grains, producing a better stability. According to the above hydrodynamic effect, BDS should influence cross-shore sediment transport in the shore zone.
Many BDS prototypes have been installed around the world; also in Italy, some examples are available, i.e. Ostia (Damiani et Al.,2003), Alassio and Procida (Vicinanza et Al.,2009). Field monitoring is very useful to assess the effectiveness of the system, even if with uncertainties in results, affected by the impossibility to control the boundary conditions. Laboratory tests (Damiani et Al.,2009) could be used in defining how does the system work in different wave conditions and drain configurations
Modeling currents and solid transport offshore Porto Cesareo (Southern Italy)
A practical application is dealt with in the present study, whose purpose is firstly the
modelling of hydrodynamics in a coastal basin located in the Southern Italy and secondly the
simulation of dredged sediments in the same area. On one side, the Protected Marine Area of
Porto Cesareo, instituted in 1998, has produced great benefits to the coastal town in terms of
environmental conditions improvement, but on the other side it has penalized some social,
tourist and economic aspects, forbidding many kind of activities along the coastal area.
Particularly, some interventions are necessary to guarantee a safe mooring for local fishing
boats, by respecting all the environmental restrictions. In this research, once analysed some
circulation patterns in typical averaged seasonal conditions, a solution to this aspect has been
evaluated. A dredging operation of the area has been hypothesized, with the use of both
hydraulic and mechanical dredges and the consequent sediment transport has been studied, so
that the impact of the operations on the aquatic environment could be considered.
Tests have been carried on with MIKE 21 model, a professional software package for twodimensional
free-surface flows. Results show that the most practicable solution is represented
by the use of hydraulic dredging in summer conditions
Experimental investigation of a vertical, round, turbulent, momentum jet in a vegetated crossflow
Measurements of the velocity and turbulence characteristics of a vertical, round, turbulent jet
discharged into a vegetated crossflow are reported. In recent years up to now a large number of experimental
studies and models on turbulent jets discharged into a crossflow have appeared in the literature. As regards
these studies, a lack of data concerning the vegetation effects on the jet behavior was observed. The present
study was directed toward obtaining a more thorough understanding of the effects of a vegetated bed channel
on a momentum (non-buoyant) jet. To achieve this, several experiments were carried out in a rectangular
channel at the hydraulic laboratory of the Water Engineering and Chemistry Department of the Technical
University of Bari (Italy). To simulate vegetation stems, orderly arrays of rigid circular cylinders, made of
steel, were used along an experimental area of 3.00 m long and 0.40 m wide. The jet source was placed at the
center of the experimental area. The hydrodynamic features of the jet have been studied with details via turbulence
statistical analyses (e.g. velocity field, turbulence intensity and Reynolds stresses). It was found that the
background turbulence generated by the vegetation strongly affects the jet behavior, i.e. the jet flow structures
become more complex and the jet penetration height, dilution, and spreading increase significantly due to the
increase of the turbulence intensities and the shear stresses
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