OPTIMIZATION OF POWER AND OPERATION CHARACTERISTICS OF A NEW EXTERNAL AXIS WIND TURBINE

A new class of wind turbine termed the external axis wind turbine (EAWT) has been recently developed. The EAWT is a new class of wind turbines that combines the low cost of vertical axis wind turbines with the high power of horizontal axis wind-turbine. This paper is a first step study that assumes a constant wind speed and a simple on-off controller. The paper optimizes the number of blades in the EAWT and the time at which the controller must be turned on to simultaneously maximize the power while minimizing the time required to reach optimal operation. The multi-objective optimization on the EAWT is performed on a response surface that is generated using Computational Fluid Dynamics (CFD) simulations. The turbulence model and mesh-sizing for the CFD simulations are validated against previously published experimental results on a buff body. To the best of authors' knowledge, this paper is the first study to investigate changing blade count, and determining optimal operation speed to simultaneously maximize power, while minimizing the time needed to reach peak operational point in wind-turbines.