Experimental investigation of augmented horizontal axis wind turbine

Abstract

An augmented wind turbine has been an interesting concept of wind energy conversion, due to the system capability to increase the performance of wind turbine relative to bare wind turbine with a similar size. Different capsulated wind energy systems have been studied to improve the performance of wind rotors by increasing the energy density of the wind. One of them is the nozzle-diffuser capsulated system. However, more studies concerned on the influence of the concentrator (nozzle) while little research has been done concerning on the diffuser influence and there is still a need to carry out experiment investigation. Therefore, this paper investigates the effect of the concentrator, diffuser and combined augmentation at different wind speed. In this paper, the main objective involves design and an experiment testing of the augmented wind turbine. Blade Element Momentum theory was used to design the blade. Glass fiber and thin sheet were used to manufacture non-twisted NACA 4412 blade and augmentation respectively. The tunnel wind speed was used in this experiment at 3 m/s, 4 m/s, 5 m/s, and 6 m/s. AC fan motor was used as a generator and direct measurement were performed for performance investigation. The result shows that all augmentation increases the power output. The average percentage of power variation between a bare wind turbine and augmented wind turbine was 33.8% for a diffuser, 88% for the nozzle and 81.6% for nozzle-diffuser combination. Also, augmentation is a capable of affecting the cut in speed.