Maritime Research Center Research Articles

MARINET experiment KNSWING testing an I-Beam OWC attenuator

The research and results presented in this paper concerns experiments on wave energy conversion carried out in the one meter deep wave tank at the Hydraulic and Maritime Research Center (HMRC) at University College Cork, Ireland in 2013. The purpose is to investigate how much power an attenuator – a ship shaped wave energy converter facing the waves with its bow – can absorb along its sides in a range of regular and irregular wave conditions.The experiments were carried out in model scale 1:50 resembling the wave conditions and water depth of the Danish part of the North Sea and a 150m long wave energy converter with 20 Oscillating Water Column (OWC) chambers on each side. The damping applied to each chamber by the Power Take Off (PTO) is modeled by forcing the air through a hole with an area of about 1.3% of the chamber water surface area.The results in irregular wave conditions shows that the converter can absorb more than 2.5MW of wave power that in wave conditions with significant wave heights of 5m. A capture width ratio between 20% and 25% was measured in the most frequent wave conditions with average periods between 5 and 7s with significant wave height of 2 m. In short crested waves the energy absorption was slightly better due to the directional spreading of energy.The tests in monochromatic waves indicate capture width ratios up to 35% in waves with a steepness of 2.5%. The capture width ratio decreases somewhat in steeper waves.The experiments with the attenuator wave energy converter demonstrated its seaworthiness and ability to absorb wave energy. The results form a valuable base for the development of a numerical model of the system that will be used for further optimization and development.

FP7 EU funded CORES wave energy project: a coordinators' perspective on the Galway Bay sea trials

The present paper gives an overview of the lessons learnt from the project called Components for Ocean Renewable Energy Systems (CORES). In the context of this European funded 7th Framework Programme research project, new components and systems for ocean energy devices were developed and trialed. The present paper also details the work packages, major achievements, significant impacts, summary results and the outcomes of the sea trials. 1. Introduction Components for Ocean Renewable Energy Systems (CORES) was an EU funded FP7 Collaborative Research Project and was coordinated by the Hydraulics and Maritime Research Centre in University College Cork (UCC). The Hydraulics and Maritime Research Centre is now integrated into UCC Beaufort Research since 2013. The CORES project was intended to further develop components and systems required by the wave energy sector such as grid interface technology, power generators, moorings, instrumentation, telemetry and power control systems. The project started in 2008 and spanned over 3.5 years. It culminated with a three-month sea trial of the systems integrated onto the quarter-scale OEBuoy Hull in Ireland's Galway Bay Wave Test Site. This test site, which is operated jointly by Sustainable Energy Authority Ireland (SEAI) and the Marine Institute (MI), was made available at no cost to the project. Thirteen partners from across seven European countries participated in the project. Although it concentrated on new concepts and components based on floating oscillating water column (OWC) systems, the majority of developments have relevance to most other wave device types. The project finished successfully on budget, but was extended by six months owing to issues concerning weather conditions and vessel availability. How this was achieved, the lessons learnt and what pitfalls need to be avoided are addressed in the present paper. Techniques and tools developed to reduce the risk involved in prototype sea trials and planning, as well as resourcing methods, are discussed. Finally, the present paper details the intellectual property (IP) generated from the project that will be available to the wider ocean energy community. The ultimate objective of the CORES project was to create a wave-to-wire modelling 'toolbox'. This toolbox would allow developers to evaluate the effect of changes in device components on the performance and economics of their devices. It was to consist of a number of numerical models or 'tools' developed within individual work packages and validated at bench scale and through laboratory scale testing at sea. Further information on these tools can be found in a number of detailed technical papers (CORES, 2011; Thiebaut, 2011) as well as on the CORES website (www.fp7-cores.eu).

Predicting and Monitoring the Evolution of a Coastal Barrier Dune System Postbreaching

O'Shea, M. and Murphy, J., 2013. Predicting and monitoring the evolution of a coastal barrier dune system postbreaching.A study of the morphodynamic evolution of a midbay barrier beach system of Inner Dingle Bay, County Kerry, Ireland is presented. The system has been under observation by the Hydraulics and Maritime Research Centre (HMRC) of University College Cork since 2008 when the Rossbeigh barrier breached. This event had been the culmination of 10 years of intensive erosion. Since breaching occurred, erosion rates have continued to increase on Rossbeigh, while offshore an ebb tidal delta continues to grow. Similar barrier inlet systems are examined in order to identify trends and features that might provide an insight into the future morphology of Dingle Bay. The study utilises field data collection sediment transport analysis and remote sensing to understand the coastal processes driving the systems evolution. The changing orientation of Rossbeigh, the relative stability of the Inch barrier beach, and the variability in ebb tidal delta were the findings of the long-term morphological part of the study. The influence of the ebb tidal delta on wave refraction, emergence of a vegetated gravel ridge in the breach zone, and the role of tidal currents in sediment transport along Rossbeigh are significant findings of the monitoring campaign. These results provide indicators of future evolution of the system. The study concludes that the realignment of the beach will continue on Rossbeigh beach while alongshore tidal currents dominate sediment transport in the breached area.

Wave farm modelling: harnessing Ireland’s greatest energy resource

Wave Energy Converters are being developed worldwide, including by a number of Irish companies, as a sustainable and environmentally-friendly means of generating electricity using the power of the ocean. By 2020 it is envisaged that hundreds of these devices will be deployed off the West Coast of Ireland in arrays known as Wave Farms and connected to the national electricity grid. The focus of my Ph.D. project, being carried out at the Hydraulics and Maritime Research Centre (HMRC) in UCC, is to create realistic models of these Wave Farms so that we can better understand their behaviour and ultimately optimise their performance. Nearly 95% of the electricity consumed in Ireland is generated from fossil fuels such as gas, coal and oil. As reserves of these resources begin to dry up, leading to scarcity of supply and increases in cost, and the environmental concerns about carbon dioxide emissions become more pronounced, ...

Privatization: a recent example at the National Maritime Research Center

Privatization: a recent example at the National Maritime Research Center

Machine tool including workpiece clamp sensor : Graham Mason, London, Canada assigned to Joseph Rhodes Limited

The research and results presented in this paper concerns experiments on wave energy conversion carried out in the one meter deep wave tank at the Hydraulic and Maritime Research Center (HMRC) at University College Cork, Ireland in 2013. The purpose is to investigate how much power an attenuator – a ship shaped wave energy converter facing the waves with its bow – can absorb along its sides in a range of regular and irregular wave conditions.The experiments were carried out in model scale 1:50 resembling the wave conditions and water depth of the Danish part of the North Sea and a 150 m long wave energy converter with 20 Oscillating Water Column (OWC) chambers on each side. The damping applied to each chamber by the Power Take Off (PTO) is modeled by forcing the air through a hole with an area of about 1.3% of the chamber water surface area.The results in irregular wave conditions shows that the converter can absorb more than 2.5 MW of wave power that in wave conditions with significant wave heights of 5 m. A capture width ratio between 20% and 25% was measured in the most frequent wave conditions with average periods between 5 and 7 s with significant wave height of 2 m. In short crested waves the energy absorption was slightly better due to the directional spreading of energy.The tests in monochromatic waves indicate capture width ratios up to 35% in waves with a steepness of 2.5%. The capture width ratio decreases somewhat in steeper waves.The experiments with the attenuator wave energy converter demonstrated its seaworthiness and ability to absorb wave energy. The results form a valuable base for the development of a numerical model of the system that will be used for further optimization and development.

Fluidisation. Edited by J. R. GRACE and J. M. MATSEN. Plenum Press, 1980. 605 pp. $69.50. Flow and Transport in Porous Media. Edited by A. VERRUIJT and F. B. J. BARENDS. Balkama, 1981. 232 pp. Ecohydrodynamics. Edited by J. C. J. NIHOUL. Elsevier, 1981. 359 pp. $58.50. Fluid Mechanics in Energy Conversion. Edited by JOHN DAVID BUCKMASTER. SIAM, Philadelphia, 1980.

Fluidisation. Edited by J. R. GRACE and J. M. MATSEN. Plenum Press, 1980. 605 pp. $40.00, DM72. By E. H. HIRSCHEL and W. MORDULLA. Freidr. Vieweg & Sohn, Wiesbaden, 1981. Photographic reproduction from camera-ready copy; paperback. SSPA-ITTC Workshop on Ship Boundary Layers 1980, Proceedings. 264 pp. Edited by L. LARSSON. Swedish Maritime Research Centre publication, Goteborg, 1981. Photographic reproduction from camera-ready copy; paperback. - Volume 116

Coastal Navigationvs.Energy Resource Recovery: The Santa Barbara Channel Study

A simulation study was performed at the National Maritime Research Center's shiphandling simulator to determine the effects of oil production and exploration structures on the navigation of large vessels using the routing scheme in the Santa Barbara Channel. As part of a risk management program being completed on behalf of the California Coastal Commission, data was collected on the responses of ship masters navigating a computer-modelled vessel through the Santa Barbara Channel in the presence of a variety of platform and drillship siting configurations. The results of the study will be incorporated in the risk management program to help in establishing guidelines for siting of exploratory drilling and oil production facilities near the shipping lanes.

Empirical Investigation of Simulator/Training System Characteristics

A cohesive research program has been initiated by the Computer Aided Operations Research Facility (CAORF) of the National Maritime Research Center to investigate the simulator-based training system. This research program has been focusing on characteristics of the simulator and other training system elements, to evaluate their relative cost effectiveness in the achievement of deck officer training objectives. This joint U.S. Coast Guard/Maritime Administration project seeks to delineate the role of the ship bridge simulator in the mariner training and licensing process. This paper will present a brief overview of this CAORF training research program. Furthermore, it will present the research findings to date at both the master/chief mate and cadet levels. Particular emphasis will be placed on the results of the master level investigation. A major product of this research program will be the development of training system acceptance criteria for use by the U.S. Coast Guard in the approval of simulator-based training programs for meeting some licensing requirements. These will constitute a major product of the current phase of the investigation. The approach being followed to develop this product will be summarized, as well as insight provided into the likely role of the ship bridge simulator in the deck officer training and licensing process in the near future.

Marine Instrumentation Developments

The National Maritime Research Center, Kings Point, N.Y., is conducting projects dealing with the “new technology” in the field of navigation. This paper consists of a survey of this area of activity of the Center. The intent is not only to disseminate information to the wide community of navigators but also to structure a mutually beneficial communications link between the NMRC and the Institute of Navigation. The paper will cover the following projects, some innovative, others extensions of previous programs: —RAPS (Radar Automatic Plotting System) —MASS (MarAd Anti-Stranding Sonar) —TRANSIM (Simplified Transit) —MARINE RADAR TRANSPONDER —MARSCAN (Maritime Satellites Communication and Navigation System) —INTEGRATED CONNING SYSTEM