|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 document outlines the issues associated with modelling the effects of bounding surfaces and/or other bodies on the flow field in and around a tidal turbine rotor.
- A review of the existing literature provides an overview of the available modelling options and also provides a basis for the selection of an appropriate level of model sophistication.
- The GH Blockage model is described and the rationalised modelling approach is justified. The GH Blockage model uses Potential flow theory to evaluate the effect of bounding surfaces and/or other surrounding turbines on a tidal turbine under investigation.
- The model is used to predict the three dimensional flow field in and around the tidal turbine, which enables the change in turbine performance to be predicted. The altered flow field around the turbine is also used in modelling the wake mixing and recovery process.
- A list of key assumptions that the GH Blockage model makes is provided along with the relevant references to existing theory.
- The method by which the mathematical models are implemented into a working code is described, as is the way in which the GH Blockage model to be incorporated within the GH TidalFarmer Beta code.
- Flow diagrams of the GH Blockage model algorithms are presented and examples of the outputs are provided