Wave experts test solutions to stabilise floating offshore wind turbines

Wave experts test solutions to stabilise floating offshore wind turbines

A computer model of an offshore wind turbine supported by a semi-submerged triangular structure

Manchester Metropolitan University has won a £124,000 grant from the Flexible Fund of the Supergen Offshore Renewable Energy Hub to develop computer models to test the best methods to stabilise and control the motions of floating offshore wind structures.

The funding for the 12-month project – ‘Passive Control of Wave Induced Platform Motions for Semi-submersible FOWTs' – is part of a wider £9m finance initiative from the Engineering and Physical Sciences Research Council.

Representative waves from the North Sea will be used in the computer simulation incorporating two proposed stabilisation measures, first testing with one and then adding the second.
The first is a tuned liquid damper is a U-shaped tube filled with water, which sloshes as the platform moves and acts as a counterbalance and helps absorb the rotational movements.

The second would use heave plates placed under the three columns like the suspension in a car to suppress the up and down motion.

Manchester Metropolitan University reader in computational fluid dynamics at the Centre for Mathematical Modelling and Flow Analysis Ling Qian said: “Under extreme wave conditions such as during storms, floating platforms will undergo large movements and sometimes this movement is dangerous and leads to system damages.

“Therefore, we need to make sure the device can survive such storms with large waves.

“On the other hand, in order for the wind turbine to operate optimally we also need to control its motion.

“There is already one commercial floating offshore wind demonstration project in the UK, a test farm off the coast of Scotland near Peterhead, but to enhance the technical viability and to drive the cost down, further fundamental research is still needed.

“In this project, we will look at some novel and cost-effective techniques to stabilise a floating system so it can operate under high sea states and survive the worst impact.”

Once Qian and his team have carried out their computer modelling, a 1:30 scale model of the turbine will be tested in a wave tank with research partners at Ningbo University in Ningbo, China.

More details: www2.mmu.ac.uk/news-and-events/news/story/10781/