Master of Philosophy in Electrical Engineering
School of Electrical, Computer and Telecommunications Engineering
Jafari, Seyed AmirHosein, Performance Analysis of PowerWindow: a Linear Wind Generator, Master of Philosophy in Electrical Engineering thesis, School of Electrical, Computer and Telecommunications Engineering, University of Wollongong, 2014. http://ro.uow.edu.au/theses/4297
Linear wind generators (LWGs) are a new type of wind turbine developed recently. Unlike the conventional horizontal or vertical axis wind turbines, the power extraction mechanism of linear wind generator is based on the translational movement of blades along a path perpendicular to the incoming wind. This study focuses on a LWG design developed at the University of Wollongong, named PowerWindow, which represents a modular wind power generator, and investigates its characteristics and performance.
The thesis develops an analytical model for PowerWindow using the modified blade element momentum theory. It also develops a simulation of this device using the computational fluid dynamic method. It is envisaged that in practice PowerWindow modules can be installed and operated in two different positions, either suspended on a frame or landed on ground. The suspended configuration means that the module is placed in an elevated position for example, between two towers, and landed configuration means that the module is placed on a flat surface, for example, the roof of a tall building. Aerodynamic mechanisms of PowerWindow in both positions are analyzed and compared using the modified blade element momentum theory and the computational fluid dynamic model, and also validated by the experimental data obtained from the prototype tests in the wind tunnel.
This study shows that the PowerWindow turbine can operate with acceptable efficiency in very low blade to wind velocity ratio, which is not achievable by conventional wind turbines at the same value of tip speed ratio. It is shown that installation position (suspended or landed) greatly affects its performance. This study also shows that the front blades can significantly impact on the performance of the rear blades, by increasing their angle of attack. Increasing the angle of attack also increases the possibility of stall. However it is also shown that stall condition can be postponed by increasing the solidity.