P. Sammarco

Landslide tsunamis propagating along a plane beach

A forced two-horizontal-dimension analytical model is developed to investigate the distinguishing physical features of landslide-induced tsunamis generated and propagating on a plane beach. The analytical solution is employed to study the wave field at small times after the landslide motion starts. At larger times, the occurrence of transient edge waves travelling along the shoreline is demonstrated, showing the differences with the transient waves propagating over a bottom of constant depth. Results are satisfactorily compared with available experimental data. Finally, the validity of non-forced numerical models is discussed.

Landslide tsunamis propagating around a conical island

An analytical forced two-horizontal-dimension model is derived to investigate landslide tsunamis propagating around a conical island lying on a flat continental platform. Separation of variables and Laplace transform are used to obtain the free-surface elevation in the whole domain and the runup at the shoreline in terms of confluent Heun functions. The main properties of these functions and their asymptotic behaviour for large parameters are investigated. Expression of the transient leading wave travelling offshore is also derived. The distinguishing physical features of landslide tsunamis propagating in a round geometry are then pointed out and compared with those of landslide tsunamis propagating along a straight coast. Analytical results satisfactorily agree with available experimental data.

Analytical modeling of drug dynamics induced by eluting stents in the coronary multi-layered curved domain

Pharmacokinetics induced by drug eluting stents (DES) in coronary walls is modeled by means of a one-dimensional multi-layered model, accounting for vessel curvature and non-homogeneous properties of the arterial tissues. The model includes diffusion mechanisms, advection effects related to plasma filtration through the walls, and bio-chemical drug reactions. A non-classical Sturm-Liouville problem with discontinuous coefficients is derived, whose closed-form analytical solution is obtained via an eigenfunction expansion. Soundness and consistency of the proposed approach are shown by numerical computations based on possible clinical treatments involving both hydrophilic and hydrophobic drugs. The influence of the main model parameters on drug delivery mechanisms is analyzed, highlighting the effects induced by vessel curvature and yielding comparative indications and useful insights into the concurring mechanisms governing the pharmacokinetics.

Theory of the synchronous motion of an array of floating flap gates oscillating wave surge converter

We consider a finite array of floating flap gates oscillating wave surge converter (OWSC) in water of constant depth. The diffraction and radiation potentials are solved in terms of elliptical coordinates and Mathieu functions. Generated power and capture width ratio of a single gate excited by incoming waves are given in terms of the radiated wave amplitude in the far field. Similar to the case of axially symmetric absorbers, the maximum power extracted is shown to be directly proportional to the incident wave characteristics: energy flux, angle of incidence and wavelength. Accordingly, the capture width ratio is directly proportional to the wavelength, thus giving a design estimate of the maximum efficiency of the system. We then compare the array and the single gate in terms of energy production. For regular waves, we show that excitation of the out-of-phase natural modes of the array increases the power output, while in the case of random seas we show that the array and the single gate achieve the same efficiency.

Effects of Moored Boats on the Gradually Varied Free-Surface Profiles of River Flows

AbstractThe last mile of rivers often represents an option worth considering for the development of ports. This is particularly true in coastal areas that are densely developed. The simplest form of a port canal, i.e., boats moored along the banks, is an attractive option for the low investment required and the often acceptable residual wave motion. Some of the major rivers have thousands of boats moored along their banks. The effect of these floaters on the river levels during floods must be taken into account. The authors present a methodology based on the computation of the forces on a single boat or an array of boats that yields a quantification of the effect on the river levels. It essentially provides an iterative procedure for computing the value of the resistance coefficient to be used in hydraulic analysis. Theoretical predictions are satisfactorily confirmed by ad hoc experimental investigation.

Met-ocean and heeling analysis during the violent 21/22 october 2014 storm faced by the sailboat ECO40 in the gulf of lion: Comparison between measured and numerical wind data

On 19 October 2014 Matteo Miceli, a known italian oceanic sailor, left the Port of Riva di Traiano (Rome, IT) with the italian sailing boat ECO 40, for the Roma Ocean World Project. This ambitious challenge consists of a non-stop sailing alone around the World in energy and food self-sufficiency. ECO 40 is a Class 40 oceanic vessel (LOA of 12,0 m) that has been equipped with a data acquisition system for measuring both the met-ocean parameters recorded (apparent and real wind speed and wind direction, atmospheric pressure, current velocity, air temperature, sea temperature, etc.) and the kinematic characteristics of the boat itself (i.e., speed and course over ground). Furthermore, the boat has been equipped with three high precision GPS receivers, provided by Leica Geosystem, for measuring the motion of the boat and an inertial platform. Due to these high-precision instruments it is possible to fully measure and characterize the six degrees of freedom of the boat, and accordingly to use her as a sailing wave buoy. Within this paper we present the analysis of the met-ocean data measured by the boat during the storm occurred in the Gulf of Lion on the 21–22 October 2014 that ECO 40 has faced just few days after her departure. Furthermore, by analyzing the GPS signals by means of an innovative application of differential kinematic positioning technique, a detailed analysis of the boat heeling during the Gulf of Lion event has been carried out. The boat heeling measurements have been used to correct the measured wind data that have been compared with the hindcast time series.

Landslide Tsunamis Propagating Along a Semi-Plane Beach

A forced three-dimension analytical model is developed to investigate the main characteristics of landslide tsunamis propagating on a semi-plane beach. The method of separation of variables and the Fourier transform are employed to obtain the solution in the form of an eigenfunction expansion. Parametric discussion and further comparison with the model of a uniformly sloping beach are finally made.© 2009 ASME