eXtreme Waves! – Wednesday, 19 September 2018

Wednesday, 19 September
Doors at 7:30pm, talks start at 8.
The Golf Tavern, 30-31 Wrights Houses, Bruntsfield, Edinburgh, EH10 4HR (www.golftavern.co.uk)

Talk 1: Extreme sea states in coastal regions: how large can the loads be?

Frederic Dias, Professor at University College Dublin

Numerous structures are damaged by the violent impacts of waves that are either breaking or very close to breaking. Design formulae for estimating the magnitude of the impulsive pressures generated by breaking waves are largely derived from the results of laboratory tests rather than from an in-depth analysis of the fundamental mechanics. Under extreme wave conditions, results are uncertain due to scale effects: the hydrodynamics requires different model scales and the influence of the various effects is difficult to infer from small-scale experiments. During this talk, we will review a recent mathematical and computational modelling framework, based on elementary loading processes (ELPs), for the analysis of wave impacts on wave energy converters and slamming inside the tanks of liquefied natural gas carriers. We will attempt to answer the question “how large can the loads be?”

Frederic Dias received a PhD in Civil and Environmental Engineering from the University of Wisconsin, Madison, USA, in 1986. He started his career in the US before coming back to France to join CNRS in 1990. In 2000, he moved to Ecole Normale Superieure Paris Saclay and has been a Professor of Applied Mathematics since. In 2009, he went to University College Dublin (UCD) on leave to work on wave energy converters. He is now leading the wave group at UCD. In 2012, he received an advanced grant from the European Research Council (ERC) to work on extreme wave events. In 2014, he received a proof of concept grant from the ERC to work on wave measurement. His stay at UCD has been extended until 2019.

NB: Frederic’s talk is the first of a two part series. The second, titled “Extreme sea states in coastal regions: how large can the waves be?”, will take place the next day (20 Sept) at 1pm at The University of Edinburgh, Hudson Beare Building, Lecture Theatre 2 (beside the EngInn). Crucially: there will be pizza!

Talk 2: Extreme loads – Slamming on an Oscillating Wave Surge Converter

Jon Nicholson, Research/Mechanical Engineer, at (the former) Aquamarine Power

Load conditions in extreme waves can be significant drivers in the design of wave energy converters. Devices that are, by definition, designed to couple heavily to the incoming wave force have to be able to withstand the loads that accompany the biggest waves. This can be done by increasing strength through structural design or by finding ways to minimise loads in these extreme cases. For both, it is necessary to understand what the design drivers are: are extreme or fatigue loads are most damaging to the structure? what are the localised loads and the global loads? In general, if the mechanism that causes the worst case loads is understood, something can be done to mitigate them and/or safety factors on design can be minimised. As an example, we will look at slam loads on an Oscillating Wave Surge Converter, how the loads were measured, reproduced and incorporated into the design process of a full scale device

Brought to you by IMechE!

Institution of Mechanical Engineers (IMechE) was founded 1847 and strives to improve the world through engineering with over 120,000 members in 140 countries. The institute helps develop engineers and promote engineering in several industry sectors (such as Aerospace, Power & Energy, Manufacturing and Railway) through events, workshops, training and more.

The Edinburgh and South East Scotland Young Members Panel exists to engage like-minded individuals and stimulate discussion, through offering activities that are not possible, or preventatively expensive, without the support of the Institution.



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