Papers by Pasquale F Filianoti
The Solitary Wave Run-Up on Sloped Beaches Protected by Submerged Rigid Breakwaters
Modeling water flow rate and soil erosion in Mediterranean headwaters (with or without check dams) under land use and climate change scenarios using SWAT
The use of check dams is a common strategy to contrast soil erosion in the Mediterranean headwate... more The use of check dams is a common strategy to contrast soil erosion in the Mediterranean headwaters. However, the effects of these control works on water flow rates and sediment yields have been scarcely investigated under possible scenarios of climate and land use changes. On this regard, the use of hydrological models, such as SWAT, provide reliable hydrological predictions under variable environmental conditions. To fill this gap, this study has evaluated the effectiveness of check dams on the hydrological response of a forest headwater in Calabria (Southern Italy) in comparison to an unregulated sub-catchment with very similar environmental conditions. On this regard, the effects of different combined scenarios of climate change (through three GCMs and two RCP applied to the next 80 years) and land use (forest, pasture, and cropland) on water flow rates and sediment yields in the two headwaters were analysed using the SWAT model. SWAT was first calibrated in a third headwater with very similar climatic, soil and land use conditions, and this verification showed a satisfactory prediction capacity of water flow rate. The water flow rate prediction capacity of the model was satisfactory (coefficients of determination and efficiency of Nash and Sutcliffe equal to 0.71 and 0.67, respectively, and percent bias of 14.9%). No significant differences were detected for the water flow rates and sediment yields between the two sub-catchments (with or without check dams) among the different land uses and climate change scenarios. This was linked to the low hydrological response of both headwaters to the forcing actions, which influenced the low effectiveness of the control works. SWAT estimated higher values of both mean and maximum values of water flow rates and sediment yields under RCP2.6 compared to RCP8.5. Both water flow rates and sediment yields will be very low under all climate and land use scenarios. The regulated headwater with check dams will always produce more runoff and erosion compared to the sub-catchment without check dams. The increases will be up to 60% for the maximum flow rate and 30-35% for the sediment yield in forest land use and under RCP2.6. Although the limitation of this study linked to the lack of validation of the erosion data (due to unavailable records of sediment yield), this study has demonstrated how the use of check dams in headwater catchments may be not effective several decades after their installation for soil conservation purposes in Mediterranean semi-arid areas, where the water flow and erosion rate are limited.
On the stability of submerged rigid breakwaters against solitary waves
Coastal Engineering, Oct 1, 2022
Large eddy simulation within the smoothed particle hydrodynamics: Applications to multiphase flows
Physics of Fluids
In this paper, the large eddy simulation (LES) model introduced in the smoothed particle hydrodyn... more In this paper, the large eddy simulation (LES) model introduced in the smoothed particle hydrodynamics (SPH) by Di Mascio et al. [Phys. Fluids 29, 035102 (2017)] and called δ-LES-SPH, is extended to treat multiphase flows. This is achieved by modifying the multiphase δ-SPH by Hammani et al. [Comput. Methods Appl. Mech. Eng. 368, 113189 (2020)] by switching the viscous and density diffusion constants to dynamic variables evaluated as turbulence closure terms. The equation for energy conservation is also written for the presented model. The validation is performed for two-dimensional problems, by comparison with other established SPH solvers, with a finite volume method solver based on the turbulence closure corresponding to that adopted for the Lagrangian scheme, and with experimental data. The first test case investigated is a modified Taylor–Green vortex in which the introduction of macro-bubbles of a lighter fluid phase inside the domain is considered. In the second test case, a m...
Water
In the last few decades, hydropower production has been moving toward a new paradigm of low and d... more In the last few decades, hydropower production has been moving toward a new paradigm of low and diffused power density production of energy with small and mini-hydro plants, which usually do not require significant water storage. In the case of nominal power lower than 20 kW and ultra-low head H (H < 5 m), Archimedes screw or Kaplan type turbines are usually chosen due to their efficiency, which is higher than 0.85. A new cross-flow type turbine called Ultra-low Power Recovery System (UL-PRS) is proposed and its geometry and design criteria are validated in a wide range of operating conditions through 2D numerical analysis computed using the ANSYS Fluent solver. The new proposed solution is much simpler than the previously mentioned competitors; its outlet flow has a horizontal direction and attains similar efficiency. The costs of the UL-PRS turbine are compared with the costs of one Kaplan and one cross-flow turbine (CFT) in the case study of the main water treatment plant of t...
Modeling water flow rate and soil erosion in Mediterranean headwaters (with or without check dams) under land use and climate change scenarios using SWAT
The use of check dams is a common strategy to contrast soil erosion in the Mediterranean headwate... more The use of check dams is a common strategy to contrast soil erosion in the Mediterranean headwaters. However, the effects of these control works on water flow rates and sediment yields have been scarcely investigated under possible scenarios of climate and land use changes. On this regard, the use of hydrological models, such as SWAT, provide reliable hydrological predictions under variable environmental conditions. To fill this gap, this study has evaluated the effectiveness of check dams on the hydrological response of a forest headwater in Calabria (Southern Italy) in comparison to an unregulated sub-catchment with very similar environmental conditions. On this regard, the effects of different combined scenarios of climate change (through three GCMs and two RCP applied to the next 80 years) and land use (forest, pasture, and cropland) on water flow rates and sediment yields in the two headwaters were analysed using the SWAT model. SWAT was first calibrated in a third headwater wi...
A comprehensive analysis of solitary wave run-up at sloping beaches using an extended experimental dataset
Applied Ocean Research
Water
The use of check dams is a common strategy to reduce soil erosion in the Mediterranean headwaters... more The use of check dams is a common strategy to reduce soil erosion in the Mediterranean headwaters. However, the effects of these control works on water flow rates and sediment yields have been scarcely investigated under possible scenarios of climate and land-use changes. On this regard, the use of hydrological models, such as SWAT, provide reliable hydrological predictions under variable environmental conditions. To fill this gap, this study has evaluated the effectiveness of check dams on the hydrological response of a forest headwater in Calabria (Southern Italy) in comparison with an unregulated subcatchment with very similar environmental conditions. In this regard, the effects of different combined scenarios of climate change (through three GCMs and two RCPs applied to a time period of the next 80 years) and land use (forest, pasture, and cropland) on water flow rates and sediment yields in the two headwaters were analysed using the SWAT model. The SWAT model was first calibra...
A Laboratory Analysis of Solitary Wave Run-Up in the Presence of Submerged Barriers
2022 IEEE International Workshop on Metrology for Living Environment (MetroLivEn)
Fluid dynamics inside a U-shaped oscillating water column (OWC): 1D vs. 2D CFD model
Renewable Energy
On the energy transmission by a submerged barrier interacting with a solitary wave
Applied Ocean Research, 2022
A Semi-Analytical Model to Calculate Forces Exerted on Horizontal Cylinder by a Solitary Wave
Volume 7A: Ocean Engineering, 2017
Several authors have studied the solitary wave load on a submerged horizontal cylinder. In the pr... more Several authors have studied the solitary wave load on a submerged horizontal cylinder. In the present work, a semi analytical expression of the horizontal force exerted by a solitary wave on a horizontal cylinder is derived. The formula is based on the speed drop factor ƒr, that is the ratio (greater than one) between the time needed by the wave pressure to cross the solid body and the travel time across a transparent cylinder. The ƒr, is calculated numerically by means of the Boundary Element Method on assuming that a solitary wave and a periodic wave having the same wavelength undergoes the same slowing down. (Clearly the wavelength for the solitary wave is estimated approximately.) Abaci for the ƒr, as a function of the ratio between the diameter and the wavelength, for assigned A/d (= amplitude of the solitary wave / bottom depth) have obtained. In order to check the appropriateness of BEM, we carried out an experiment in a numerical wave flume, using the Computational Fluid Dy...
Wave Flume Tests to Check a Semi-Analytical Method for Calculating Solitary Wave Loads on Horizontal Cylinders
Volume 7A: Ocean Engineering, 2017
In this work, the solitary wave loads on a submerged horizontal circular cylinder are studied by ... more In this work, the solitary wave loads on a submerged horizontal circular cylinder are studied by comparing new analytical results with ad-hoc experimental data. The proposed analytical solution has been recently proposed by Gurnari and Filianoti (2017) and represents an extension of the formulation developed by Filianoti and Piscopo (2008) to assess the solitary wave loads acting on a submerged breakwater and tested in a wave flume on a small-scale model (Filianoti and Di Risio, 2012). Here we deal with a submerged horizontal cylinder following the concept that a solitary wave is subjected to a slowdown passing over a submerged cylinder. A laboratory investigation was addressed to calibrate the adopted semi-analytical method. The speed of the solitary wave celerity crossing the solid submerged cylinder was measured for several wave amplitudes. In the adopted wave flume at the University of Calabria equipped by a piston-type wavemaker, an horizontal cylinder with diameter D = 0.127 m...
Water, 2021
We present an analysis related to the evaluation of Morison and transverse force coefficients in ... more We present an analysis related to the evaluation of Morison and transverse force coefficients in the case of a submerged square barrier subject to the action of solitary waves. To this purpose, two-dimensional experimental research was undertaken in the wave flume of the University of Calabria, in which a rigid square barrier was provided by a discrete battery of pressure sensors to determine the horizontal and vertical hydrodynamic forces. A total set of 18 laboratory tests was carried out by varying the motion law of a piston-type paddle. Owing to the low Keulegan–Carpenter numbers of the tests, the force regime of the physical tests was defined by the dominance of the inertia loads in the horizontal direction and of the lift loads in the vertical one. Through the use of the time series of wave forces and the undisturbed kinematics, drag, horizontal inertia, lift, and vertical inertia coefficients in the Morison and transverse semi-empirical schemes were calculated using time-doma...
A CFD analysis of the wave field in front of a U-OWC breakwater
Progress in Renewable Energies Offshore, 2016
The Performance of an "Active" Submerged Breakwater by a CFD Analysis
Wave forces on a U-OWC breakwater
Sustainability, 2020
Benchmarking techniques are useful and simple tools to analyze the performance of the collective ... more Benchmarking techniques are useful and simple tools to analyze the performance of the collective irrigation in the Water User Associations (WUAs) towards an increase in service sustainability. Several benchmarking techniques have been proposed to process and predict performance indicators. Instead, some meaningful statistical techniques based on the distance of data samples, which overcome the limitations of the traditional benchmarking techniques, have never been applied to the collective irrigation sector. This study applies Permutational Multivariate Analysis of Variance (PERMANOVA), Multidimensional Scale Models (MDS), and Distance-Based Linear Models (DISTLM) as benchmarking techniques to evaluate the technical and financial performances of 10 WUAs in Calabria (Southern Italy). These benchmarking techniques revealed that the significant differences in the irrigated areas and financial self-sufficiency of the WUAs, shown by PERMANOVA, depend on the large variability of the remai...
Hydrology, 2020
In order to predict and control the impacts of floods in torrents, it is important to verify the ... more In order to predict and control the impacts of floods in torrents, it is important to verify the simulation accuracy of the most used hydrological models. The performance verification is particularly needed for applications in watersheds with peculiar climatic and geomorphological characteristics, such as the Mediterranean torrents. Moreover, in addition to the accuracy, other factors affect the choice of software by stakeholders (users, modellers, researchers, etc.). This study introduces a “performance matrix”, consisting of several evaluation parameters weighted by stakeholders’ opinions. The aim is to evaluate the accuracy of the flood prediction which is achieved by different models, as well as the pros and cons of software user experience. To this aim, the performances and requisites of four physical-based and conceptual models (HEC-HMS, SWMM, MIKE11 NAM and WEC-FLOOD) have been evaluated, by predicting floods in a midsized Mediterranean watershed (Mèsima torrent, Calabria, So...
Coastal Engineering, 2020
A laboratory and numerical investigation on the features of the horizontal and vertical hydrodyna... more A laboratory and numerical investigation on the features of the horizontal and vertical hydrodynamic loads given by a solitary wave on a submerged square barrier is presented. By the experimental viewpoint, the wave forces were deduced from the records of a discrete battery of pressure sensors located along the external surface of the barrier. As regards the numerical viewpoint, simulations were performed through the SPH model presented in Di Mascio et al. (2017), in which the governing equations are written considering a turbulence closure model. The numerical simulations allowed to extend the range of analyzed cases and highlighted the regions around the submerged barrier of higher dissipation occurring during the wave-structure interaction. A good agreement between the experimental and numerical peaks of the horizontal and vertical forces was found. Afterwards, a semi-analytical scheme able to determine the horizontal loads was adopted using the speed drop factor obtained by physical tests and simulations. For practical purposes, attention was finally paid to determine the critical conditions against the sliding of the barrier.
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Papers by Pasquale F Filianoti