Wave-modelling tool could improve offshore structures

The design and maintenance of offshore structures such as oil rigs and wind turbines could benefit from a new wave-modelling tool currently in development.

The project is a collaboration between City University London and engineering consultant GL Noble Denton and is in response to oil and gas exploration moving into deeper waters and the take-off of renewable projects.

‘You need to estimate the wave force produced by very large waves, particularly overturning waves, and the impact of these on structures must be accurately modelled. At the moment there is no efficient tool to do this — people are using empirical, linear formulae to estimate waveload, which are not accurate enough,’ said project lead Prof Qingwei Ma of City University London.

The software tool will help design engineers build optimised structures that are resilient to a range of conditions. In addition, it will help insurers create risk profiles and inform the decision-making process around existing structures.

‘Some structures, such as offshore pipes, might have been built 20 years ago, when we had a poorer understanding of waves, and in addition to that, climate change has perhaps made wave conditions different. So we need to know if we can continue to use this structure for the same purpose or for other purposes — for example, we might want to build wind turbines on existing structures and we need to know if it will be sufficiently strong,’ Ma said.

He told The Engineer that when the modelling tool is sufficiently advanced its performance and accuracy will be tested on structures that are currently managed by GL Noble Denton.

The university has received £103,000 from the EPSRC and Finance South East to commercialise research by its Hydrodynamic Engineering Group, and GL Noble Denton will also contribute £50,000 to the work.

Dr R V Ahilan, managing director of advanced engineering consulting at GL Noble Denton, said: ’Our engineers are engaged in developing offshore assets the world over, which must be safe, sustainable and affordable. The research at City will aid this, by enabling us to generate designs with a much better understanding of the forces that they must stand up to under extreme conditions.’