E. Renzi
Research Group
Publications
This is a selected list of published papers. Please click on the titles to download.
For a complete list of my publications please visit my Research Gate profile.
J. Thompson, E. Renzi, A. Sibley, D. Tappin, 2020
Weather, DOI:10.1002/wea.3741
A revised and update catalogue of meteotsunami events on UK coasts.
Effects of the sound speed vertical profile on the evolution of hydroacoustic waves
S. Michele, E. Renzi, 2020
Journal of Fluid Mechanics 883, A28.
A novel analytical model for the evolution of hydroacoustic waves in weakly compressible fluids characterised by depth variations of the sound speed profile.
Power extraction in regular and random waves from an OWC in hybrid windwave energy systems
S. Michele, E. Renzi, C. PerezCollazo, D. Greaves, G. Iglesias, 2019
Ocean Engineering 91, 106519
Mathematical and experimental models of a novel oscillating water column (OWC) in a hybrid windwave energy system.
A secondorder theory for an array of curved wave energy converters in open sea
S. Michele, E. Renzi 2019
Journal of Fluids and Structures 88, 315330
A secondorder nonlinear theory for an array of curved flaptype wave energy converters (WECs) in open sea, excited by oblique incident waves
Weakly nonlinear theory for a gatetype curved array in waves
S. Michele, E. Renzi, P. Sammarco, 2019
Journal of Fluid Mechanics 869, 238263.
We analyse the effect of gate surface curvature on the nonlinear behaviour of an
array of gates in a semiinfinite channel.
Unlike the case of linearised theories, synchronous excitation of trapped modes is now possible because of interactions between the wave field and the curved boundaries at higher orders.
The pressure impulse of wave slamming on an oscillating wave energy converter
E. Renzi, Y. Wei, F. Dias, 2018
A pressureimpulse model of the slamming of a flapping plate, including the effects caused by air entrapment near the plate.
O'Brien , L., Renzi, E., Dudley, J., Clancy, C., Dias, F., 2018
Natural Hazards and Earth System Sciences 18, 729758.
A catalogue of documented extreme wave events (storm waves, tsunamis, storm surges, rogue waves) in Ireland dating back as far as the turn of the last ice age and as recent as 2017.
Dias F., Renzi E., Gallagher S., Sarkar D., Wei Y., Abadie T., Cummins C., Rafiee A., 2017
Acta Mechanica Sinica 33 (4) 647662.
New analytical and numerical models have been pushed to their limits to provide answers to open questions relating to the operation and characteristics of wave energy converters.
Renzi E., 2017
Journal of Fluid Mechanics 812, 525.

We investigate the hydroelectromechanical coupled dynamics of a piezoelectric wave energy converter.

The effect of the piezoelectric coupling in the hydroelastic domain generates a system of short and longcrested weakly damped progressive waves travelling along the plate. We show that the shortcrested flexural wave component gives a dominant contribution to the generated power.

We determine the hydroelectromechanical resonant periods of the device, at which the power output is significant.
Renzi E., 2016

We investigate the hydroelectromechanical coupled dynamics of a piezoelectric wave energy converter.

The effect of the piezoelectric coupling in the hydroelastic domain generates a system of short and longcrested weakly damped progressive waves travelling along the plate. We show that the shortcrested flexural wave component gives a dominant contribution to the generated power.

We determine the hydroelectromechanical resonant periods of the device, at which the power output is significant.
Renzi E., Sammarco P., 2016
Landslides 13, 13691377.
 Landslidegenerated tsunamis are lesserknown yet equally destructive than earthquake tsunamis.

We review the state of the art of landslide tsunami analytical modelling. Within the framework of a linearised shallowwater theory, we illustrate the dynamics of landslide tsunami generation and propagation along beaches and around islands.

We highlight some intriguing new directions in the analytical modelling of landslide tsunamis to support early warning systems.
Michele S., Sammarco P., d'Errico M., Renzi E., Abdolali A., Bellotti G., Dias F., 2015
 We consider a flap gate farm, i.e. a series of P arrays, each made of Q neighbouring flap gates, in an open sea of constant depth, forced by monochromatic incident waves.
 The effect of the gate thickness on the dynamics of the system is taken into account.
 We show that synchronous excitation of the natural frequencies of Sammarco et al. (2013) yields large amplitude response of gate motion. This aspect is fundamental for the optimisation of the gate farm for energy production.
Effect of a straight coast on the hydrodynamics and performance of the Oscillating Wave Surge Converter
Sarkar D., Renzi E., Dias F., 2015

We model the effect of a straight coast on the hydrodynamics of the wave energy deviceOscillating Wave Surge Converter.

Extremes in the hydrodynamic coefficients are observed for certain specific locations of the device.

The presence of the coast has both – favourable and detrimental effects on the device performance.

When located very close to the coast, the device consistently achieves much higher levels of efficiency than it would do in an open ocean.
O'Brien L., Christodoulides P., Renzi E., Stefanakis T., Dias F., 2015

The question posed here is whether an oscillating wave surge converter (OWSC) could withstand the force of an incoming tsunami.

Several tools are used to provide an answer: an analytical 3D model developed within the framework of linear theory, a numerical model based on the nonlinear shallow water equations and empirical formulas.

Numerical results show that runup and drawdown can be amplified under some circumstances, leading to an OWSC lying on dry ground!
Renzi E., Dias F., 2014
Journal of Fluid Mechanics, 754, 250262

We consider the mechanics of coupled underwateracoustic and surfacegravity waves generated by surface pressure disturbances in a slightly compressible fluid.

We show that pressure changes on the ocean surface, localised in space and time, can induce appreciable underwater compression waves which are precursors of the surface gravity waves.

We derive new results for the underwater compression wave field and discuss the dynamics of its generation and propagation.

This work could lead to the design of innovative alert systems for coastal flooding management.
Sarkar D., Renzi E., Dias F., 2014
Proceedings of the Royal Society A, 470, 20140118

We analyse the hydrodynamic behaviour of a wave energy farm consisting of oscillating wave surge converters in oblique waves.

We observe a strong wave focusing effect in special configurations comprising a large number of devices.

In general, the flaps lying on the front of the wave farm exhibit an enhanced performance behaviour in average, owing to the mutual interactions arising within the array.

A random sea analysis shows that a slightly staggered arrangement can be an ideal layout for a wave farm of this device.
Renzi E., Doherty K., Henry A., Dias F., 2014
European Journal of Mechanics B/Fluids, 47, 124131

We introduce a new reference mathematical model, the ‘‘flaptype absorber’’.

A flaptype absorber is a large thin device which extracts energy by pitching about a horizontal axis parallel to the ocean bottom.

We provide a simple – yet accurate – physical interpretation of the laws governing the mechanism of wave power absorption by Oyster.

We emphasise why some other, more established, mathematical theories cannot be expected to accurately describe its behaviour.
Dias F., Dutykh, D., O'Brien L., Renzi E. and Stefanakis T., 2014
Procedia IUTAM, 10, 338355

We review some of the basic generation mechanisms as well as their simulation.

We present a simple and computationally inexpensive model that describes the seabed displacement during an underwater earthquake.

We also consider an unusual source for tsunami generation: the sinking of a cruise ship.

We review some aspects of tsunami runup. In particular, we explain why the first wave of a tsunami is sometimes less devastating than the subsequent waves.

We also look at a particular feature of the 11 March 2011 tsunami in Japan—the formation of macroscale vortices.
Renzi E., Abdolali A., Bellotti G. and Dias F., 2014
Renewable Energy, 63, 5568.

We model a finite array of oscillating flaptype wave energy converters.

We develop new semianalytical and fully numerical highend computational models.

We identify a nearresonant mechanism responsible for constructive interference among the converters which enhances the power production.

We discover the existence of an optimum gap with which further maximises the power production.
Renzi E. and Dias F., 2013
European Journal of Mechanics B/Fluids, 41, 110.

We model a single oscillating wave energy converter in the open ocean.

We develop a novel highend computational model.

We show that increasing the flap width has the beneficial effect of broadening the bandwidth of the capture factor curve.

We quantify the degree of accuracy of wave tank experiments aiming at reproducing the performance of the device in the open ocean.
Relations for a periodic array of flaptype wave energy converters
Renzi E. and Dias F., 2013
Applied Ocean Research, 39, 3139.

We investigate the interaction of plane incident waves with a wave farm in the open ocean.

Asymptotic analysis of the wave field allows us to obtain new expressions of the reflection, transmission and radiation coefficients of the system.

Unlike a line of heaving buoys, an array of flaptype converters is able to exploit resonance of the system transverse modes in order to attain high capture factor levels.

Relations between the hydrodynamic coefficients are derived and applied for optimising the power output of the wave farm.
Renzi E. and Dias F., 2012
Journal of Fluid Mechanics, 701, 482510.

We develop a mathematical model to study the behaviour of an oscillating wave energy converter in a channel.

We analyse the physical behaviour of the system, showing sensitivity of the resonant sloshing modes to the geometry of the device.

We validate our results with available numerical and experimental data.
Renzi E. and Sammarco P., 2012
Natural Hazards and Earth System Sciences, 12, 15031520.

We propose an advancement in analytical modelling of landslide tsunamis propagating along a plane beach.

We investigate the influence of slide shape on the propagating waves and the role of the continental platform in attenuating the wave amplitude along the shoreline.

Comparison with experimental data is very good.
Renzi E. and Sammarco P., 2010
Journal of Fluid Mechanics, 650, 251285.

We derive an analytical forced twohorizontaldimension model to investigate landslide tsunamis propagating around a conical island.

We obtain a solution in terms of Confluent Heun function, whose asymptotic behaviour for large parameters we investigate.

The distinguishing physical features of landslide tsunamis propagating in a round geometry are then pointed out and compared with those of landslide tsunamis along a straight coast.

Analytical results satisfactorily agree with available experimental data.
Sammarco P. and Renzi E., 2008
Journal of Fluid Mechanics, 598, 107119.

We develop a computational model to investigate landslideinduced tsunamis generated and propagating on a plane beach.

For the first time, we demonstrate mathematically the occurrence of transient edge waves travelling along the shoreline, induced by the landslide.

Results compare satisfactorily with available experimental data.
Wave actions on the side caissons of the Venice gates
Sammarco P. and Renzi E., 2007
Applied Ocean Research, 29, 210220.

The study originates from a construction problem found in the planned deployment of the side caissons of the Venice gates barrier.

An analytical model based on the method of matched asymptotics is developed in order to obtain the free surface oscillations caused by a grazing incident wave.

The resonant response of the basin and the amplification factors are then determined.

In irregular wave motion, the dynamic actions can be significant, due to the excitation of different resonant modes.