Combined BEM-CFD Modelling of Tidal Stream Turbines Using Site Data

Abstract

Marine currents have the potential to provide a

large proportion of Britain’s energy generation requirements.

Whilst a number of devices capable of utilizing this resource

are under development, there is at present little exploitation of

marine energy. One potential generator of energy in this area is

tidal stream turbines (TST). However, since they are expensive

to install, engineers need to ensure that the TST will deliver

optimum performance once they are in place. This performance

is dependent on a number of features that are specific to the

surrounding environment, including the underlying bathymetry

and variation of the current both temporally and within the

water column. Computational fluid dynamics (CFD) is a useful

tool for predicting what impact the surrounding environment

and supporting structure will have on the performance of a

TST. In this paper the importance of using measured site data to

develop CFD models for TSTs is demonstrated. A CFD model

of a TST is presented and two designs for the supporting

structure are investigated. A parametric study is carried out

using a flat bed model. Finally, a series of results is presented

for a site in the Severn Estuary using a bathymetry defined bed.