Research themes
The marine energy research group addresses the development and evaluation of models to simulate the loading, performance and environmental impact of devices for generating electricity from ocean waves or tidal streams. Experimental work is conducted in a unique combined wave and current flume, a wave flume, several open channels and in a wind tunnel. In parallel, a range of numerical models are employed to analyse specific problems; Smooth Particle Hydrodynamics has been employed to simulate response of devices to extreme wave loading, CFD (CFX and CODE_SATURNE) employed to simulate the loading of tidal stream turbines due to large-scale turbulence and linear wave theory (WAMITTM) used to study the response and optimisation of arrays of devices.
Wave devices typically comprise one or more floating bodies whose oscillation drives an electric generator. Devices are designed to generate electricity from average wave heights of up to 2 m but must also resist damage during extremely severe individual waves that are an order of magnitude larger. Tidal stream devices typically comprise a turbine to generate electricity from bidirectional flows with average velocities greater than 2 m/s. Some tidal stream devices are based on the configuration of a wind turbine but the presence of a free-surface above the device and of large-scale turbulence within the flow presents different design problems. Since individual devices generate relatively low average power output (e.g. 1 MW), large arrays of devices will be required for commercial electricity generation. For both types of device it is important to understand how the configuration of an array can be determined to maximise power output and minimise environmental impact. The group employs a combination of experimental and numerical approaches to improve understanding of design methods for both individual devices and arrays of devices.
Wave energy devices and tidal stream devices could provide a substantial contribution to UK electricity demand and represent a major export market for the UK. Several projects are supported by collaborations with industrial partners including: Electricite de France, Tecnalia Robotiker, GL-Garrad Hassan and Offshore Design Engineering amongst several others.