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The NOEL, Natural Ocean Engineering Laboratory, of Reggio Calabria (Italy)

NOEL, Lungomare Falcomatà, Rada delle Mura Greche, Reggio Calabria, Italy

Felice Arena Professor of Ocean Engineering Mediterranea University Director of NOEL

ANNO ACCADEMICO DUEMILAUNDICI/DUEMILADODICI

NOEL, prof. Felice Arena Reggio Calabria, www.noel.unirc.it

The first ocean engineering laboratory working in the field rather than in wave tanks equipped with wavemakers based on the successful experience of some pionieeristic small-scale-field- experiments directed by Professor Paolo Boccotti off the beach of Reggio Calabria (Italy), since 1989.

NOEL, professor Felice Arena Reggio Calabria, www.noel.unirc.it

Ionian Sea

Tyrrhenian Sea

Sicily

Calabria

Messina Reggio Calabria

Messina STRAITS OF MESSINA Reggio Calabria

NOEL lab

L O C A T I O N

Reggio Calabria NOEL

http://upload.wikimedia.org/wikipedia/commons/e/e3/Reggio_calabria_panorama_dal_fortino.jpg�


LOCATION Beach of Reggio Calabria on the East coast of the Strait of Messina. Peculiarity. A local wind from NNW often generates sea states consisting of pure wind waves with the typical size of a big laboratory tank (significant wave height 0.20m<Hs<0.80m, peak period 2.0s<Tp<3.6s). This local wind is very stable, and sometimes keeps steady from morning to evening. The tide amplitude is small (typically within 0.10m). The water is very clear because of the current which flows twice in a day.


THE ORIGIN OF LABORATORY On 1989 Professor Paolo Boccotti directed the first experiment aimed at verifying the possibility to work in the sea as in a big wave tank. In 1990 a small scale field experiment was carried out off the beach of Reggio Calabria to verify the theory of Quasi-Determinism, that defines the mechanics of three-dimensional wave groups when a very high wave occurs. The results of the experiment gave a full confirmation of the theory (Boccotti et al. 1993) and showed that the sea off the Reggio Calabria promenade is a natural lab for “small scale field experiments” (Phillips et al. 1993). Here a local wind blowing from Messina toward Reggio Calabria generates wind waves with spectra very close to the mean JONSWAP, spectrum during most time of a year.


THE ORIGIN OF LABORATORY …………….. After three more experiments the Mediterranea University of Reggio Calabria decided to build a laboratory in the promenade of Reggio Calabria. The municipality of Reggio Calabria included the laboratory in a big project for the city seaside. This includes an open theatre and a new promenade with a splendid sight of the Straits of Messina and Sicily. The new laboratory has its own beach, and its own water sheet within 50m from the shoreline. It includes a conference room, a room with the electronic station and a P.C. network, offices and a small workshop. The small scale field experiments are performed in the water sheet off the beach. The instruments are connected by cables to the electronic station. People attending symposia held in this lab can get a real time view of the experiments.


The new management and the N.O.E.L. In March 2009 the Mediterranea University of Reggio Calabria assumed direct management of the laboratory, and Professor Felice Arena was designated as Director of the Lab, supported by the Scientific Supervision of Professor Paolo Boccotti (they are both full professor of Ocean Engineering). In this new phase of the lab, activities are run with the support of the PhD students of the ocean engineering program, as well as graduate students, which participate to the experiments. In the lab academic activities, as lectures for under graduate students, are also held.


The Staff of the N.O.E.L. (2009/2010): Professors and researchers of the Mediterranea University

(Alessandra Romolo, Giuseppe Barbaro, Paolo Boccotti, Vincenzo Fiamma, Felice Arena)


The Staff of the N.O.E.L.: With some PhD students and PostDoc of the Mediterranea University


The Staff of the N.O.E.L. Ph.D. Students: Ocean Engineering Program

Name Ciclo Tutor(s) Name Ciclo Tutor(s)

Antonino Campolo XXIV Prof. Giuseppe Barbaro Rosa Maria

Calaudi XXVI Prof. Felice Arena

Dott.ssa A. Sempreviva

Rosita Siciliano XXIV Prof. Felice Arena Alessandro Richichi XXVI Prof. Felice Arena

Giandomenico Foti XXIV Prof. Giuseppe Barbaro Anita Santoro XXVI Prof. C. Guedes Soares Prof. Felice Arena

Luigi Collia XXV Proff. P.Boccotti, V. Fiamma,

Domenico Ciricosta XXVII Prof. Felice Arena

Pasquale Pizzimenti XXV Prof. Felice Arena Valentina Laface XXVII Proff. F. Arena, G. Barbaro

Simona Ghiretti XXV Prof. Giuseppe Barbaro Giovanna Vizzari XXVII Proff. F. Arena, A. Romolo

Post-Doc in Ocean Engineering Saveria Meduri (PhD – ciclo XX) Vincenzo Nava (PhD – ciclo XXI) International Post-doc between Mediterranea

and Instituto Superior Tecnico of Lisbon, Portugal Antonino Viviano (PhD – ciclo XXI) Giovanni Malara (PhD – ciclo XXIII) International Post-doc between

Mediterranea and Rice University of Houston, Texas, USA


Lectures in the N.O.E.L. (2009-2010):

Prof. Pol D. Spanos (Rice University, USA) Prof. F. Einaudi Prof. P. Boccotti NASA,USA


Prof. Carlos Guedes Soares, Instituto Superior Tecnico, Lisbon


Professor Franco Einaudi Goddard Space Flight Center

NASA, USA

May, June 2011


Professor Pol D. Spanos, Rice University, Houston Texas, USA - April 2011


Professor Francesco Fedele Georgia Institute of Technology, USA

June 2011

XXI


PhD in Ocean Engineering Final exams – cicle XXI - 2009

Committee: Professors Pol D. Spanos, Mario Di Paola, Alessandro Mancinelli, Federico Mazzolani, Eugenio Pugliese Caratelli PhD in Ocean Engineering : Vincenzo Nava, Antonino Viviano; PhD in Structural Engineering and Materials: Carmen Amaddeo, Francesco Marino, Massimiliano Pappatico

XXIII XXII


PhD in Ocean Engineering Final exams – cicle XXII - 2010

PhD in Ocean Engineering Final exams – cicle XXIII - 2011

Committee: Professors Paolo Blondeaux, Leonardo Damiani, Luciano Nunziante, Giuseppe Rega. PhD in Ocean Engineering: Erminia Capodicasa, Viviana Russo; PhD in Structural Engineering and Materials: Olga Barrera, Concetta Tripepi

Committee: Professors Pol D. Spanos, Eugenio Pugliese Carratelli, Paolo Sammarco, Roberto Capozucca. PhD in Ocean Engineering: Alfredo Ascanelli; PhD in Structural Engineering and Materials: G. Alfredo A.C. Cundari


A PROTOCOL FOR JOINT SUPERVISION OF DOCTORAL RESEARCH has between signed in 2011 between Universidade Técnica de Lisboa (Portugal) and Mediterranea University of Reggio Calabria. This agreement, within the “Agreement between Instituto Superior Tecnico, Portugal and Mediterranea University of Reggio Calabria, Italy, on Academic and Research Exchange and Collaboration”, which has been signed in December 2007 (the designated operational officers, for purposes of developing and implementing the terms of the agreement are: for Instituto Superior Técnico: Prof. Carlos Guedes Soares; for Mediterranea University of Reggio Calabria: Prof. Felice Arena), provide joint supervision for doctoral research, subject to current Portuguese and Italian legislation on doctoral studies. The candidate Anita Santoro will carry out the research work under the supervision of a designated supervisor from each of the two universities: Doctor Professor Carlos Guedes Soares of Universidade Técnica de Lisboa Professor Felice Arena of Mediterranea University of Reggio Calabria At the viva voce examination, the candidate Anita Santoro will defend the thesis in the English language and will give an oral summary in the English language. In compliance with legislation in force in each country, and based on the official report drawn up after the viva voce examination, both the degree of Doutor in Naval Architecture and Marine Engineering will be conferred by Universidade Técnica de Lisboa and the PhD (dottorato di ricerca) in “Ingegneria Marittima dei Materiali e delle Strutture” by Mediterranea University of Reggio Calabria (Italy) will be conferred on the candidate Anita Santoro.


Early experiments of Professor Paolo Boccotti

in the natural ocean engineering laboratory

of Reggio Calabria


NOEL experiment RC1990, on mechanics of three-dimensional wave groups in the open sea, and formation of exceptionally high waves.

There were nine vertical piles of small section on deep water, each with instruments for measuring the free surface displacement, and pressure transducers for measuring the fluctuating pressure head beneath the water surface. The experiment aimed to check the basic predictions of the quasi-determinism theory: an exceptionally high wave in a wind generated sea-state occurs because of the transit of a characteristic wave group at the apex of its development. The theory is based on a closed-form solution of probabilistic wave mechanics, and describes in details this three dimensional wave group, giving not only the free surface displacement but also the velocity potential.


1990 Mechanics of three-dimensional wave groups in the open sea, and occurrence of exceptionally high waves. ….. In particular the theory shows that, whichever the spectrum of the sea state, the wave group has a development stage which is followed by a decay stage. During the development stage, the envelope and the wave crest shrink and as a consequence the height of the central wave of the group grows up to a maximum. The opposite occurs during the decay stage. The individual waves have a propagation speed greater than group’s speed, so that each of them runs along the envelope from the tail where it is born to the head where it dies. As a consequence each individual wave experiences some great transformations during its evolution, especially when the three dimensional wave group is close to the apex of its development.


NOEL experiment RC1991. Mechanics of three-dimensional wave groups interacting with a vertical breakwater, and formation of high waves at the breakwater and in the water sheet before the breakwater. A special vertical breakwater 12m long was built on 1.5m water depth. Thirty wave gauges were assembled in the water sheet before the breakwater. The experiment aimed to check the quasi-determinism theory for what concerns waves interacting with a reflecting wall. In particular the theory predicts that an exceptionally high wave at the wall, most probably is the central wave of a three-dimensional group hitting the breakwater, at the apex of its development stage.


NOEL experiment RC1991. Mechanics of three-dimensional wave groups interacting with a vertical breakwater, and formation of high …. The theory predicts that, an exceptionally high wave at a point far from the breakwater, most probably, is the outcome of two wave groups at the apex of their development, which strike each other in full at this point. The experiment also aimed to verify some predictions on the frequency spectrum as a function of the distance from the breakwater.


NOEL experiment RC1992. Mechanics of random wave forces on gravity offshore platforms.

The 1:50 scale model of a gravity offshore platform was towed and sank on 2.5m water depth. A first set of transducers was placed at the base and at a column of the platform. A second set of transducers with the same configuration of the first set, and on the same water depth, was placed at some distance from the platform. Thus it was possible to get a real time comparison between the wave force on the solid body and the wave force on an equivalent water mass (Froude Krylov force).


NOEL experiment 1993. Wave forces on large horizontal cylinders. This experiment was similar to RC1992 with the difference that here the solid body was the 1:30 scale model of a submerged tunnel. Like in RC1992 there were two sets of pressure transducers, one at the solid body (tunnel) and one with the same spatial configuration, at some distance from the solid body so as to get a real time comparison between the wave force and the Froude-Krylov force. Two kinds of tunnels were tested. First: a tunnel of 27m diameter for the railway and the highway. Second: a tunnel of 13.5m diameter for the railway only. The most typical Hs (significant wave height) of the small wind waves of Reggio Calabria is 0.30m, and we fix the model scale as equal to the quotient between this most typical Hs and the design Hs of the prototype. In the case of the experiment RC1992 (model of the gravity offshore platform) the design Hs of the prototype was 15m so that the model scale was 1:50. In the case of the experiment RC1993 (model of a submerged tunnel) the design Hs of the prototype was 9m so that the model scale was 1:30.


NOEL experiment 1994. Mechanics of random wave forces on vertical breakwaters. A small vertical breakwater 12m long was assembled like in the experiment RC1991. This time a set of transducers was put at various elevations at the wall centre. The aim was to analyze the wave pressure on this kind of structure, both under wave crests and wave troughs. The effects of high water jets like that of the photo were deeply investigated.


NOEL exp 2001. Submerged caisson for absorbing sea wave energy. In autumn 2001 we assembled a 1/10 scale model of one caisson of the so called ‘invisible breakwater’ disclosed by Professor Boccotti. This breakwater consists of caissons well beneath the water level (at full scale: 3-5m beneath the mean water level). Hence, we are dealing with a breakwater with a very low environmental impact. Under wave action water enters into (or exits from) the caissons, and as a consequence an air pocket (1) in a room inside the caisson is compressed or expands.

3

8.5

1

122

21

5

2.5SECT A-A

1.7

BB

11


compressore polmone d'aria

x

Air pocket

Air compressor

NOEL exp 2001. … On tuning the height of the air pocket, it is possible to induce resonance. Thanks to resonance the plant can absorb a large share of the incident wave energy. This energy is wasted inside the caissons. The experiment showed that, on tuning the height in the air pocket, it is possible to get an impressive amplification of the random pressure fluctuations inside the plant. Moreover the experiment confirmed that the height of the waves off a beach can be controlled on opening or closing two valves on the beach.


NOEL exp 2005. Vertical breakwaters for converting sea wave energy into electric power. On spring 2005 we assembled a 1/10 scale model of a caisson breakwater with a U-OWC embodied (size of the model: 16.2m length, 2m water depth, weight about 300tons). The U-OWC converts the chaotic wave energy into the energy of a high speed air current in a tube. The energy of this air current can be converted into electric power by means of a Wells turbine. In the experiment 2005 there was no turbine, so that there was only the first step: from the chaotic wave energy to the energy of the air current in the tube.


NOEL exp 2005. Vertical breakwaters for converting sea wave energy into electric power. The aim of the experiment was not to improve the design empirically on changing size and shape of the various part of the plant. On the contrary, the design had be performed up to details, analytically, on exploiting a powerful tool for design which is the Quasi Determinism of the largest sea waves (Boccotti, 2000; chaps. 9-10). The experiment aimed to verify two things of general interest, which emerged from the Boccotti’s solution (2007) for the interaction waves U-OWC. Specifically, the experiment aimed to verify whether or not the plant can convert the very 100% of the energy of the long swell, thanks to a super amplification of these swell, amplification that cannot expand towards the open sea, since the propagation speed of the reflected wave energy approaches zero. This time the confirmation was really spectacular: in a number of records of long swell, nearly the 100% of the wave energy was converted into the energy of the air current in pressure, and this occurred thanks to some super amplifications of the waves at the breakwater embodying the U-OWC, just as it was predicted.


2

3

0.8

0.45

0.45

1.55

-1.65

+0.3

Saracinesche / turbine

1.30

2 massi guardiani

0.33

Blocchi zavorra in calcestruzzo

Mare

1

2Terra

3 tube

Concrete ballast

Seaward 8

+3.5

20

2 5

0.4

3.4

Comparison: a traditional caisson

And a REWEC3 caisson

IIIIII

II

Sez. I

+3.5

20

2.3

5

3

1

0.7

0.5

II

1 5

2.5

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4.5

F

larghezza media condotto: 2.5

8

NOEL exp 2005. Vertical breakwaters for converting sea wave energy into electric power.


Experiments in the NOEL

with the new management

of the Mediterranea University (Spring 2009- Spring 2011)

Director: Professor Felice Arena Scientific Supervisor: Professor Paolo Boccotti


NOEL exp 2009 a. Directional spectra in coastal area measured by two gauges The first experiment (of May 2009) dealt with the directional spectrum recorded by wave gauges, either ultrasonic probes measuring the free surface elevation or the transducers, measuring the wave pressure.


NOEL exp 2009 b/c. Sea wave forces on a vertical wall The experiment dealt with the wave pressures and the wave forces on vertical walls at sea. This experiment was carried out for different relative water depths, in May (exp b) and in October-December, (exp c) to analyze the extreme pressures and forces on the wall when high waves occur. The wave force was measu-red by means of a set of pressure transducers, on the mid vertical section of the wall.


NOEL exp spring 2009d. Hydrodynamic forces of sea waves on horizontal submerged cylinders At the end of September 2009 a new experiment started, to analyze the wave forces on cylinders. The first experiment was carried out by considering a vertical cylinder. The wave force is measured by means of a set of pressure transducers in a horizontal section of the cylinder

1.2m1.45m

2.0m

1.8m

wave pressures

z

x

ultrasonic probes

0.75m


NOEL exp spring 2010. Waves and QD in space-time domain

15.0m

-2.0m

-5.0m

0.0

1.20

m

1 3 5 7 9 11 13 15 17 19 21 23 25

2 4 6 8 10 12 14 16 18 20 22 24 26

15.0my

horizontal beam

θ

y

wave direction

22.0m

In the spring of 2010, an experiment was carried out on the wave group mechanics and statistics in space time domain. The Boccotti’s Quasi-Determinism theory predicts that the high waves during storms are joined in groups; all wave groups with high waves have the same characteristics and have similar changing during they propagation. During this experiment, 26 wave gauges were used for recording waves simultaneously. The result is a full and spectacular validation of the QD theory. It has been found that wave groups, when a very high wave occurs (very high with respect to the mean wave height), recorded in different days, are very close to each other! A very important consequence in ocean engineering: freak waves (or giant waves) during a storm have all the same characteristics and have the same evolution during they propagation.


In October 2010 a new experiment has started, on hydrodynamic forces of sea waves on horizontal submerged cylinders (tunnels of pipelines). A submerged cylinder is supported by the structure shown in the picture (in the Northern part of the Lab). It is possible to see two ultrasonic probes which record the free surface displacement (red circles). The forces on the cylinder are recorded by means of eight pressure transducers in the vertical mid section of the submerged cylinder. It is the first experiment in the world on sea wave forces on submerged pipelines, carried out at sea with techniques of laboratory

NOEL exp autumn 2010-spring 2011. Hydrodynamic forces of sea waves on horizontal submerged cylinders


NOEL exp 2011. Waves and QD in space-time domain in front of a vertical breakwater


New experiments in NOEL during 2012: 1. Wave group mechanics and statistics in space time domain: a

new experiment in deep water.

2. OCEAN WAVE ENERGY A new small scale field experiment on a REWEC3 device, with a turbine to produce electrical power from ocean waves. Project POSEIDONE supported by Italian government department on Environment (Rome, Italy) – in collaboration with WAVENERGY.IT limited company

3. OFFSHORE WIND FARMS: a small scale experiment on supports (fixed or floating) for wind energy devices, offshore


Selected papers on historical experiments in the natural ocean engineering laboratory (up to 2007) P. Boccotti, G. Barbaro, L. Mannino, A field experiment on the mechanics of irregular gravity waves, Journal of

Fluid Mechanics, 252, 173-186, 1993 P. Boccotti, G. Barbaro, L. Mannino, V. Fiamma, A. Rotta, An experiment at sea on the reflection of the wind

waves, Ocean Engng., 20, 493-507, 1993 P. Boccotti, A field experiment on the small scale model of a gravity offshore platform, Ocean Engng., 22, 615-

627, 1995 P. Boccotti, Inertial wave loads on horizontal cylinders: a field experiment, Ocean Engng., 23, 629-648, 1996 P. Boccotti, A general theory of three-dimensional wave groups., Ocean Engng., 24, 265-300, 1997 F. Arena, Statistics of wave forces on large horizontal cylinders, Ocean Engng, 29/4, 359-372, 2002. Arena, F. & Fedele, F. (2002). A family of narrow-band non-linear stochastic processes for the mechanics of

sea waves. European Journal of Mechanics - B/Fluids, Vol. 21, Issue 1, pp 125-137 Boccotti, P., On a new wave energy absorber, Ocean Engineering, 30, 1191–1200, 2003 Arena, F. (2006). Interaction between long-crested random waves and a submerged horizontal cylinder.

Physics of Fluids, Vol. 18, Issue 7, paper 076602, pp. 1-9, doi: 10.1063/1.2213867 Boccotti P., Filianoti P, Fiamma V, Arena F., 2007. Caisson breakwaters embodying an OWC with a small

opening — Part II: A small-scale field experiment. Ocean Engineering. vol. 34, pp. 820-841 ISSN: 0029-8018.

Arena, F. & Filianoti, P. (2007) A small-scale field experiment on a submerged breakwater for absorbing wave energy, ASCE Journal of Waterway, Port, Coastal, and Ocean Engineering, Volume 133, Issue 2, pp. 161-167, doi:10.1061/(ASCE)0733-950X(2007)133:2(161)

Boccotti P., 2008. Quasi-determinism theory of sea waves, ASME Journal Offshore Mechanics and Arctic Engineering JOMAE, Vol. 130, pp. 1-9. paper 005802JOM (the paper was the invited lecture given at the 2006 OMAE Congress in Hamburg).

http://dx.doi.org/10.1063/1.2213867�


Selected papers on historical experiments in the natural ocean engineering laboratory (up to 1994)

Books Boccotti, P., Idraulica Marittima, UTET, 1997, 1-522. Boccotti, P., Wave Mechanics for Ocean Engineering. Elsevier, Amsterdam, 2000.


Selected papers - ISI journals and books- on experiments in NOEL (2010-present) Boccotti, P., Arena, F., V. Fiamma & G. Barbaro (2010) Drag and inertia coefficients for the Morison

equation, being obtained from a small scale field experiment, Computational Stochastic Mechanics. Edited by G. Deodatis and P. D. Spanos, Research Publishing :: www.rpsonline.com.sg, ISBN: 978-981-08-7619-7, pp. 116-123.

Boccotti, P. (2010) field experiment on random-wave forces on vertical cylinders. part i: possibility of simulating the random process, Computational Stochastic Mechanics. Edited by G. Deodatis and P. D. Spanos, Research Publishing :: www.rpsonline.com.sg, ISBN: 978-981-08-7619-7.

Arena, F. (2011) Nonlinear ocean wave groups with high waves, Instituto Superior Tecnico Anniversary Book “Marine Technology and Engineering”, CRC Press/Balkema – Taylor & Francis Group, Vol. 1, pp. 5-20.

Boccotti, P., Arena, F., Fiamma, V., Romolo, A. & Barbaro, G. (2011) Estimation of mean spectral directions in random seas, Ocean Engineering, Vol. 38, Issue 2-3, pp. 509–518

Boccotti, P. (2011) Field verification of quasi-determinism theory for wind waves in the space–time domain , Ocean Engineering, Vol. 38, Issue 13, September 2011, Pages 1503-1507

Boccotti, P., Arena, F., Fiamma, V., Romolo, A. & Barbaro, G. (2012) A small scale field experiment on wave forces on upright breakwaters, ASCE Journal of Waterway, Port, Coastal, and Ocean Engineering, Vol. 138, Issue 2, pp. 97-114.

Boccotti, P., Arena, F., Fiamma, V., Barbaro, G. (2012) Field experiment on random-wave forces on vertical cylinders, Probabilistic engineering mechanics, Vol. 28, pp. 39-51

Boccotti, P., Arena, F., Fiamma, V. (2012) Distributions of wave heights in time domain in stationary sea states, accepted for publication in ASCE Journal of Waterway, Port, Coastal, and Ocean Engineering

Boccotti, P., Arena, F., Fiamma, V., Romolo, A. (2012) Two small-scale field experiments on the effectiveness of Morison’s equation, under revision in Ocean Engineering.

http://www.rpsonline.com.sg/�

http://www.rpsonline.com.sg/�


Italian newspapers

about NOEL activity on wave energy


Corriere della Sera

21 giugno

2011 Pagina 33


la Repubblica

16 giugno 2011


Il Fatto Quotidiano

26 giugno 2011


For further information, please visit

www.noel.unirc.it

or contact the Director, Professor Felice Arena

(telephone +39 3355387968, Email: [email protected])

Thank you!

the noel, natural ocean engineering laboratory, of reggio ... · the noel, natural ocean ....

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