Wind turbine performance and dynamics
The work described in the dissertation consists of various experimental investigations involving a 5 metre diameter horizontal-axis wind turbine at the Cambridge field test site and a model wind turbine in the low-speed wind tunnel at the Central Electricity Research Laboratories. The first chapter is introductory, summarising previous work by the author's research group and placing the present work in its wider context. The second chapter describes measurements and analysis of the problem of tower shadow for a downwind turbine - the 5m machine - including the use of a streamlined fairing to alleviate the problem. There follow three chapters relating to the broad area of wind turbine performance. The first of these reports how power measurements made in two different ways have been used to define the performance of the 5m machine, giving results in good agreement with theoretical predictions. The next discussed the use of blade-mounted spoilers as a control mechanism and describes experiments which have been carried out with spoilers of a simple design. Chapter 5 concerns the subject of control strategies. Both computer simulation and experimental results are presented for several different operating strategies, with particular attention to the impact on power production. The final chapter describes work carried out in a wind tunnel using a small model turbine. A comprehensive investigation of the model's wake has been undertaken and is analysed with reference to blade loading, ambient turbulence and downstream development.