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1

Investigation of signals of the range 10-3 - 10-4 Hz registered by water-tube tiltmeters in the underground geodynamic laboratory in Książ (SW Poland)

Kaczorowski Marek, Kasza Damian, Zdunek Ryszard, Wronowski Roman

Artificial Satellites : Journal of Planetary Geodesy

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2022

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Vol. 57, No. 4

210--236

EN

The Geodynamic Laboratory in Książ includes investigations of various kinds of geodynamic signals. Among others, we registered harmonic signals of the range 10-3 - 10-4 Hz. These signals had been found in the measurement series of the long water-tube (WT) tiltmeters. The discovered signals consist of two classes of harmonics associated with various kinds of phenomena. The first class of these signals belongs to viscoelastic vibrations of the Earth’s solid body, while the second class is produced possibly by the extremely long atmospheric infrasound waves. The signals of the vibrations of the Earth had been well recognized by the characteristic frequencies of the Earth’s free vibrations’ resonance, which occur mainly after strong earthquakes. The atmospheric pressure microvibrations affected the water level in the hydrodynamic systems of the WTs as a result of an inverse barometric effect. We observed that signals from both classes blend in the harmonics of similar frequencies and jointly affect the hydrodynamic systems of the WTs. We found that the amplitude of the secondclass signals strongly depends on the location of water-tube gauges inside the underground, while the amplitudes of the first-class signals are similar for all the gauges. These observations clearly indicate the atmospheric origin of the second class of registered signals.

2

Behavior of sea level in the period of 1980 to 2017 on the port area of gulf of Maranhão, Brazil

Alfredini P., Arasaki E., Fortner E.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2021

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Vol. 15 No. 3

683--686

EN

The Gulf of Maranhão, North Coast of Brazil, is one of the regions in the world with largest tidal ranges. The Port Area of Maranhão, in São Marcos Bay, represents the second most important in Brazil. The port facilities are naturally sheltered from swell, with nautical operations and maintenance dredging volumes directly conditioned by macro-tides, which exceed the 6.0 m tidal range, and associated tidal currents, which can reach 7.0 knots. In order to assess the behavior of sea levels in recent decades, in view of the influence of climate changes on tides in various ports around the world, a period of two lunar nodal tidal cycles of 18.61 years, from 1980 to 2017, was investigated using unpublished data recorded in tide gauges. The trend pattern obtained was analyzed statistically and, unlike many other port areas, a sensitive stability of the mean sea level was noted. An important conclusion is about the reduction in HHW and increasing in LLW, leading to a reduction in tidal ranges, in tidal currents and a significant reduction of the shear stress in the bottom, which may increase the dredging rates in the port areas in the next decades, due to an increasing siltation.

3

Kelvin-Helmholtz instabilities in the Colorado River Delta, Gulf of California

Carbajal Noel, Vargas José Tuxpan, Rodríguez Juan Heberto Gaviño, Ley Yovani Montaño, León David Alberto Salas de

Oceanologia

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2021

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No. 63 (3)

321--328

EN

In the Colorado River Delta, the interaction of tidal currents and sea-bottom sediment formed, in geological times, large-scale seabed patterns known as sandbanks. These patterns are oriented along the delta, almost parallel to the dominant tidal flow, with the bathymetry having an undulating character across the delta. Calculations and analysis showed that the interaction of tidal currents with the bathymetry causes velocity shears, faster flowing over the ridges than in the troughs. Kelvin-Helmholtz instabilities emerge from the velocity shear, and a large amount of suspended sediment makes the instabilities visible in satellite images. The physical and dynamic conditions allowed us to find an explanation for the existence of these Kelvin-Helmholtz instabilities. Since sandbanks have been observed in different seas such as the North Sea, The Gulf of Korea, the Gulf of Khambhat in India, the Jiangsu coast in China, the Persian Gulf, and Moreton Bay in Australia, the results suggest the existence of instabilities in these areas. Satellite images, intense tidal currents, undulating topography, and suspended sediment made it possible to explain the generation and identification of Kelvin-Helmholtz instabilities.

4

A Preliminary Study and Analysis of Tidal Stream Generators

Kashem Saad bin Abul, Majid Molla E., Tabassum Mujahid, Ashraf Azad, Guziński Jarosław, Łuksza Krzysztof

Acta Energetica

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2020

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nr 1

6--14

EN

For a sustainable future, tidal energy can play a vital role. Tidal energy relies on the gravitational pull of the Moon and the Sun along with the centrifugal forces created by the Earth. Tidal barrage uses the potential energy from the tide and has been very successful in electricity production. With the help of a turbine, kinetic energy can also be harnessed from tidal currents to generate electricity. However, it is not economically feasible to use this type of technology for large scale production of electrical energy. It is important to note that the development of this technology is still in the early stage. This research paper provides a preliminary discussion of tidal energy generation using a few different technologies. Initial research has been done using Computational Fluid Dynamics and SolidWorks software on the tidal stream generator and tidal barrage system. Some of the key challenges are also identified in terms of the development of the tidal energy conversion system.

PL

W przyszłości dla pozyskiwania energii opartego na zrównoważonym rozwoju istotną rolę może mieć energia pływów morskich. Energia ta jest rezultatem grawitacyjnego oddziaływania Ziemi, Księżyca i Słońca oraz sił odśrodkowych wytwarzanych przez układ Ziemia–Księżyc. Zapory pływowe do produkcji energii elektrycznej wykorzystują energię potencjalną fal. Przy użyciu turbin wodnych do generowania elektryczności można wykorzystać także energię kinetyczną prądów pływowych. Jednak wykorzystanie tego rodzaju technologii do produkcji energii elektrycznej na dużą skalę nie jest na razie ekonomicznie uzasadnione. Należy zauważyć, że rozwój tej technologii jest jeszcze na wczesnym etapie rozwoju. W niniejszym artykule omówiono wytwarzanie energii elektrycznej z pływów morskich przy zastosowaniu różnych technologii. Przeprowadzono wstępne badania symulacyjne przykładowego generatora pływowego oraz zapory pływowej z użyciem programów Computational Fluid Dynamics i SolidWorks. Przedstawiono także niektóre wyzwania związane z projektowaniem i budową systemów konwersji energii pływów morskich.

5

Predicting the occurrence of sandy seabed macroforms in the areas dominated by tidal processes

Kusek K., Mioskowska M.

Biuletyn Instytutu Morskiego w Gdańsku

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2018

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Vol. 33, No. 1

15--23

EN

The main aim of the article is the review study of semidiurnal tides impact into the seabed surface sedimentary structures. Presented results of numerical modeling created on the basis of previous studies is focused on changes in the marine bedforms caused by strong bottom currents and their correlation with previous research in Europe – the southern part of the North Sea and in the USA at the Long Island coast. Particular attention was given to the velocity and frequency of rhythmic tidal events. Described hydrodynamic models include also the values of depth, sediment grain size as well as stresses between marine water and the sandy bottom. Results confirmed the effectiveness of used method in the study of changes in the bedforms height and length and the need to consider other factors to obtain more accurate results. Important from the point of view of the research of seabed macroforms and processes causing their formation is also the fact that intense transport of sandy material may condition human activity, primarily the interference in surface sedimentary structures shape, e.g. during foundation of hydrotechnical constructions, cables and pipelines, offshore wind farms or construction of port infrastructure. For these reasons, there is necessary to investigate what factors affect the areas of modern shelves and determine the sediment transport.

PL

Głównym celem artykułu jest przegląd badań naukowych dotyczących oddziaływania pływów półdobowych na powierzchniowe struktury sedymentacyjne dna morskiego. Przedstawione wyniki uzyskane przy użyciu modeli numerycznych stworzonych na podstawie prowadzonych wcześniej badań koncentrują się na zmianach wysokości i rozstępu piaszczystych form morfologicznych w środowiskach zdominowanych przez występowanie silnych prądów przydennych przy jednoczesnej korelacji z uzyskanymi rezultatami analiz przeprowadzonych w Europie (południowa część Morza Północnego) oraz USA (wybrzeża Long Island, NY). Szczególną uwagę poświęcono prędkościom prądów pływowych i ich częstotliwości. Zastosowane modele hydrodynamiczne uwzględniają również zmiany głębokości, średnicy ziaren osadu oraz naprężenia występujące pomiędzy wodą morską a powierzchnią dna. Uzyskane rezultaty potwierdzają efektywność zastosowanej metody badań w prognozowaniu zmian rozstępu i wysokości form akumulacyjnych dna, ale także potrzebę uwzględniania większej ilości parametrów hydrodynamicznych w celu uzyskania bardziej dokładnych wyników. Istotny punktu widzenia opisywanych badań makroform oraz procesów kierujących ich powstawaniem wydaje się być fakt, iż intensywny transport materiału skalnego może warunkować działalność człowieka, przede wszystkim jego ingerencję w zmiany powierzchni dna morskiego między innymi podczas posadawiania budowli hydrotechnicznych, kabli i rurociągów, farm wiatrowych czy budowy infrastruktury portowej.

6

Ocena zmiany w czasie liczb Love’a k2 i k3 na podstawie danych SLR satelitów LAGEOS

Jagoda M., Rutkowska M., Kraszewska K.

Biuletyn Wojskowej Akademii Technicznej

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2017

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Vol. 66, nr 3

83--98

PL

W pracy wyznaczono liczby Love’a dla pływów drugiego i trzeciego stopnia (liczby k2 i k3). Wyznaczenie przeprowadzono na podstawie danych SLR satelitów LAGEOS-1 i LAGEOS-2 za okres 1.01.2014-1.01.2016. Uzyskane wyniki porównano z naszym wcześniejszym wyznaczeniem dla okresu 1.01.2005-1.01.2007 w celu oceny ich zmiany w czasie oraz wskazania ewentualnych zmian systematycznych. Otrzymane wartości parametrów k2 i k3 wynoszą odpowiednio: 0,29867±0,0001 i 0,0898±0,0047 (dane LAGEOS-1) oraz 0,29858±0,0001 i 0,0867±0,0047 (dane LAGEOS-2). Różnią się one od wartości uzyskanych w naszej poprzedniej pracy [25] o –0,00293 (dane LAGEOS-1) i –0,00202 (dane LAGEOS-2) dla liczby k2 oraz o –0,0091 (dane LAGEOS-1) i 0,0057 (dane LAGEOS-2) dla liczby k3. Różnice te mogą wskazywać na wystąpienie zmiany w czasie wartości k2 i k3.

EN

In this paper, we present the estimated Love numbers for degree 2 and 3 (k2 and k3). The determination was based on the Satellite Laser Ranging (SLR) data of LAGEOS-1 and LAGEOS-2 satellites obtained within the period of January 1, 2014 until January 1, 2016. The results were compared with our previous determination of these parameters for the period from January 1, 2005 until January 1, 2007 to examine whether any systematic differences and time evolution occur. The adjusted values for the k2 and k3 parameters are, 0.29867±0.0001 and 0.0898±0.0047 (LAGEOS-1 data), respectively and 0.29858±0.0001 and 0.0867±0.0047 (LAGEOS-2 data). The discrepancies between the k2 and k3 values obtained in our previous paper [25] and this analysis are: –0.00293 (LAGEOS-1 data) and –0.00202 (LAGEOS-2 data) for k2 and –0.0091 (LAGEOS-1 data) and 0.0057 (LAGEOS-2 data) for k3. The obtained discrepancies in the k2 and k3 values may indicate their change over time.

7

Energy retrieval from sea currents and tides

Szelangiewicz T., Żelazny K.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2015

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nr 41 (113)

24--29

EN

Seas and oceans show variations in water levels caused by tides and continuous flow of water in the form of sea and ocean currents. Tides are most visible close to the coastline – tide parameters (water speed or change in sea level) allow construction of installations producing electric energy. Sea currents – superficial and deep are characterized by means of constant speeds and directions. Therefore energy retrieval from these elements of sea environment looks very promising. The article presents basic information on tides and currents useful for designing hydroelectric power plants. The already constructed hydroelectric power stations are also presented here together with several design solutions of future such installations.

8

Modelling flow in the porous bottom of the Barents Sea shelf

Massel S.R.

Oceanologia

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2013

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No. 55 (1)

129-146

EN

In their recent paper, Węsławski et al. (2012) showed that the Svalbardbanken area of the Barents Sea is characterized by a high organic carbon settlement to the permeable sea bed, which consists of gravel and shell fragments of glacial origin. In the present paper, which can be considered as a supplement to the Węsławski et al. paper, two potential hydrodynamic mechanisms of downward pore water transport into porous media are discussed in detail. In particular, estimated statistical characteristics of the pore water flow, induced by storm surface waves, indicate that the discharge of water flow can be substantial, even at large water depths. During stormy weather (wind velocity V=15 m s-1 and wind fetch X =200 km) as much as 117.2 and 26.1 m3 hour-1 of water filter through the upper 5 m of the shell pit at water depths of 30 and 50 m respectively. For a porous layer of greater thickness, the mean flow discharge is even bigger. The second possible mechanism of flow penetration in the porous layer is based on the concept of geostrophic flow and spiral formation within the Ekman layer. Assuming that the current velocity in the near-bottom water layer is u- = 1 m, the resulting mean discharge through this layer becomes as large as 0.99 and 0.09 m3 s-1 for downstream and transverse flows respectively.

9

Investigating prediction performance of an artificial neural network and a numerical model of the tidal signal at Puerto Belgrano, Bahia Blanca Estuary (Argentina)

Pierini J., Lovallo M., Telesca L., Gómez E.

Acta Geophysica

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2013

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Vol. 61, no. 6

1522--1537

EN

In the present study we compare performances of the prediction of hourly tidal level variations at Puerto Belgrano, a coastal site in the Bahia Blanca Estuary (Argentina), by means of the MOHID model, which is a numerical model designed for coastal and estuarine shallow water applications, and of an artificial neural network (ANN). It was shown that the ANN model is able to predict the hourly tidal levels over long term duration with at least seven days of observations and with a better performance in respect to the numerical model. Our findings can be useful to implement ANN-based tools for future studies of the hydrodynamics of Bahía Blanca estuary.

10

Pływy i ich znaczenie ekologiczne na przykładzie wybrzeża morza północnego w dolnej Saksonii w Niemczech

Pawełko K., Jasińska A.

Ekologia i Technika

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2012

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R. 20, nr 6

341-348

PL

Niniejszy artykuł przedstawia ekologiczną rolę pływów i powstającego w wyniku ich działania morza wattowego. Obszar ten rozciąga się od miasta Den Helder w Holandii do Esbjerg w Danii. Na terytorium Niemiec znajduje się około 60% tego biotopu, z czego znaczna część na wybrzeżu Morza Północnego Dolnej Saksonii. Do powstania morza wattowego, oprócz istnienia pływów przyczyniło się kilka innych czynników, m.in.: wyspy powstałe od strony otwartego morza, płasko nachylone dno morskie, delikatny materiał denny, umiarkowany klimat. Efektem ich współdziałania jest powstanie trzech zasadniczych biotopów. W miejscach pomiędzy wałem przeciwpowodziowym a linią brzegową powstają łąki halofilne będące wysoko wyspecjalizowanym ekosystemem. Obok żyjących tam gatunków słonorośli, ważną rolę odgrywają glony, mięczaki, robaki i skorupiaki. Warunki siedliskowe wykazują pewną strefowość, co uwidacznia się też w składzie florystycznym. Kolejnym biotopem jest watt, czyli część morza wattowego cyklicznie odsłaniana i ponownie zalewana podczas zmian pływów. Najbliżej brzegu występuje watt ilasty, którego powierzchnia pokryta jest delikatnym materiałem. Występują tam przede wszystkim glony stanowiące pokarm dla małych ślimaków Littorina littorea oraz Hydrobia ulvae. Bliżej wybrzeża powstaje watt mieszany z piaskiem, gliną i cząstkami organicznymi na powierzchni. Spotykamy tam małże Macoma balthica i Mya arenaria oraz wieloszczety AreriicoZa ma-riria i Lanice conchilega. W strefie, gdzie woda ma jeszcze dużą siłę, transportowane są ciężkie cząstki piasku i powstaje watt piaszczysty. Żyją tam małże Cerastoderma edule i Mytilus edulis. Piaszczyste wydmy tworzące się głównie na wschodniej i północnej stronie wysp wschodniofryzyjskich są następnym biotopem. Z biegiem czasu w drodze sukcesji ekologicznej następuje ich stabilizacja dzięki obecności specyficznych gatunków roślin, m.in.: Ammophila arenaria, Leymus arenarius, Elymus farctus i Eryngium maritimum. Wydmy są miejscem wylęgu ptaków, np. Tadorna tadorna i Larus sp. Morze watowe ma ogromne znaczenie ekologiczne. Jest. miejscem m.in,: życia wielu gatunków roślin i zwierząt, wędrówek ptaków, rozrodu i wychowu wielu gatunków ryb Morza Północnego, biologicznego oczyszczania wód morskich. Ponadto wydmy, zwłaszcza na wyspach, chronią ląd przed zatapianiem. W 1986 r. utworzono Park Narodowy Dolnosaksońskie Morze Wattowe. Teren parku rozciąga się pomiędzy miastami Emden i Cuxhaven. Ochronie podlegają wymienione typy biotopów oraz pas wybrzeża, piaszczyste wyspy i ławice piasku.

EN

The following article presents the ecological role of tides and the formation of the Wadden Sea that results from their activity. This area stretches from Den Helder in Netherlands to Esbjerg in Denmark. Approximately 60% of this biotope is localized in Germany and a considerable part is situated on the North Sea coast of Lower Saxony. Apart from tides, there are some other factors contributing to the existence of the Wadden Sea i.e.: islands created from the open sea side, flatly sloped seabed, delicate seabed material, moderate climate. The effect of their cooperation results in the formation of the three main biotopes. In the areas between flood embankments and the coastline halophile meadows are created, which are a highly specialized ecosystem. Apart from the halophile species that reside there, an important role is played by algae, mollusks, bugs and crustaceans. Habitat conditions show a certain zone preference which is also seen in the floristic composition. Another biotope is watt, that is the part of the sea being cyclically uncovered and consecutively flooded by water during the change of tides. The argillaceous watt, which settles closest to the shore. is covered by a delicate material. The area is mostly covered by algae which constitute as food for small snails Litlorina littorea and Hydrobia ulvae. A watt mised with sand, clay and surface organic particles is created closer to the shore. Macoma balthica and Mya arenaria clams can be seen there, as well as Arenicola marina and Lanice conchilega polychaeta. In the zones where water still has a lot of force, heavy particles of sand are transported and the sandy watt appears. Cerastoderma edule i Myttlus edalis clams live there. Sandy dunes formed mostly on the east and north part of the East Frisian Islands are another type of biotope. Over the course of time through ecological succession their stability increases thanks to specific kinds of plants i.e.: Ammophila arenaria, Leymus arenarius, Elymus farctus and Eryngium marilimum. The sand dunes area is the breeding place for birds like Tadorna tadorna and LOTUS sp. The Watt Sea is of great ecological importance. It is a natural habitat for many plants and animals, a place for bird migration, breeding and rearing of many North Sea fish species and a place where biologic water cleansing occurs. Furthermore, sand dunes, especially those placed on islands, protect the land from flooding. In 1986 the Lower Saxon Watt Sea National Park was created. The park premises spread along the Cities of Emden and Cuxhaven. The mentioned biotopes, coast line, sand islands and sandbanks are under protection.

11

A brief analysis of North Sea physics

Sündermann J., Pohlmann T.

Oceanologia

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2011

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No. 53 (3)

663-689

EN

The current state of understanding the North Sea's physical system is presented. First, basic phenomena like astronomical tides and general circulation will be described and analysed with respect to their physical nature and respective interactions. There will be special focus on fundamental dynamic balances. Next, some specific topics relevant to the marine ecosystem, the economy and society will be considered: among them, spreading and transport processes, the fresh water budget, the heat budget and storm surges. A separate section is dedicated to the North Sea of Tomorrow, i.e. the prospective variations of the physical environment resulting from global changes in future decades. The statements are based on the long experience of the authors and their groups and include findings that are little known if at all. The review finishes with a list of open questions and the corresponding research demands.

12

Two models of parameterized convection for medium-sized icy satellites of Saturn

Czechowski L.

Acta Geophysica

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2006

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Vol. 54, no. 3

280-302

EN

A parameterized theory of convection is developed for 6 medium-size icy satellites (MIS) of Saturn. It is an extension of the research concerning the Mimas -Enceladus paradox. Two parameterizations of dimensionless temperature are used in the model and a new constrain for tidal heating is included. It is found that the basic results of the model are independent of particulars of the parameterizations. The new constrain considerably reduces the space of possible values of the material parameter of satellites but the two basic conclusions are unchanged, i.e.: (a) the thermal state of the considered MIS can be explained in the frame of the uniform model that includes radiogenic and tidal heating; (b) the theory indicates that endogenic activity of some MIS was (or is) a result of a specific ‘excited’, high temperature state of a given satellite. The theory could be also used for estimation of tidal heating.

13

VAV and ETERNA. Comparison between two Earth tides analysis ideas

Bogusz J., Lemanska K.

Reports on Geodesy

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2005

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z. 2/73

181-189

14

Tidal observations astrogeodetic observatory at Jozefoslaw

Bogusz J.

Reports on Geodesy

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2005

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z. 2/73

191-198

15

Contribution of long-term tide components to sea level variations

Wiśniewski B.

Oceanological and Hydrobiological Studies

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2005

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Vol. 34, No.2

5--14

EN

Some long-term sea level fluctuations at the Świnoujście gauging station reflect periodicities consistent with long-term components of the tidal forces of the moon and the sun as well as the planets. This paper presents results of a spectral analysis of monthly-normalized sea level values. Their relations with the long-term tidal force potential were determined. They can be the primary cause of sea level fluctuations.

16

Energia pływów oceanicznych

Berowski P., Grochowski G.

Nowa Elektrotechnika

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2005

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nr 3 (7)

11--13

17

The distribution and tapping tidal energy

Kowalik Z.

Oceanologia

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2004

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No. 46 (3)

291-331

EN

Tidal power along tidal shores has been used for centuries to run small tidal mills. Generating electricity by tapping tidal power proved to be very successful only in the last century through the tidal power plant constructed in 1967 in La Rance, France. This used a large barrier to generate the sea level head necessary for driving turbines. Construction of such plants evolved very slowly because of prohibitive costs and concerns about the environmental impact. Developments in the construction of small, efficient and inexpensive underwater turbines admit the possibility of small scale operations that will use local tidal currents to bring electricity to remote locations. Since the generation of such electricity is concerned with the tidal energy in local water bodies, it is important to understand the site-specific energy balance, i.e., the energy flowing in through open boundaries, and the energy generated and dissipated within the local domain. The question is how to tap the tidal energy while keeping possible changes in the present tidal regimes to a minimum. The older approach of constructing barrages may still be quite useful in some locations. The basics of such tidal power plants constructed in a small bay are analyzed in order to understand the principal parameter for tidal plant evaluation, i.e., the power produced. The new approach is to place turbines - devices similar to windmills - in the pathway of tidal currents. Theoretically, the amount of power available by such turbines for electricity generation is proportional to the water density and velocity cubed of the tidal flow. The naturally dissipated tidal power due to bottom friction forces is also proportional to the cube of the velocity. Because of this similarity, the exploitation of tidal energy can be directed to reinvesting the naturally dissipated power into tidal power for the generation of electricity. This approach to tidal power exploitation is better tuned towards preservation of the natural tidal regime. To answer the many questions related to tidal regime changes, it is important to develop a new branch of tidal dynamics which will help to better understand the interaction between a natural tidal regime and future changes caused by tapping into tidal energy.