Cross-Flow Turbine Hydrodynamics
The urgent need to establish a clean, safe and affordable energy supply has placed increased emphasis on the exploitation of new renewable energy sources. The ocean offers immense potential for clean energy extraction and research over the past few decades has shown that tidal stream turbines could play a significant role in the future energy supply chain.
A group of researchers from the Department of Engineering Science at the University of Oxford are developing an innovative turbine design aimed at maximising the cost effectiveness of energy extraction from tidal streams. The Transverse Horizontal Axis Water Turbine (THAWT) is a cross-flow turbine, which possesses superior structural characteristics in comparison to more conventional Darrieus type turbines.
The objective of the project within the Tidal Energy group is to understand the underlying flow physics of such marine cross-flow turbines and to optimise the hydrodynamic design of THAWT.
Small- and medium-scale experimental tests have been carried out to examine the effect on turbine performance of changes to the turbine’s design parameters, such as blade camber and turbine solidity. These tests have been complimented by theoratical and computational models of the turbine flow.
An extensive CFD study is being conducted to improve the understanding of the hydrodynamics of cross-flow turbines including dynamic stall and whirl effects. This investigation should enable a hydrodynamically superior design to be developed for THAWT. Additional medium-scale tests will be carried out to examine the design optimisations derived from the results of the CFD computations.