|The Performance Assessment of Wave and Tidal Array Systems (PerAWaT) project, launched in October 2009 with £8m of ETI investment. The project delivered validated, commercial software tools capable of significantly reducing the levels of uncertainty associated with predicting the energy yield of major wave and tidal stream energy arrays. It also produced information that will help reduce commercial risk of future large scale wave and tidal array developments.
This report details simulations of a model scale three-bladed axial flow tidal turbine operating in sheared flow. The simulations are based on a series of experiments carried out as part of the PerAWaT project (WG4 WP1 D4), where velocity and bed roughness parameters are modified to produce a range of flow conditions.
The rotor is modelled through both the blade-resolved and RANS-BEM methods. Rigid lid and volume-of-fluid (VOF) free surface approximations are employed.Good agreement is observed for standard rotor performance coefficients, and fair agreement is attained for velocity profiles extracted from the turbine wake under various operating conditions, validating the numerical approaches and models.
A full matrix of simulations is tabulated, with the results of a selection of these presented in detail and compared to corresponding EDF data.