Aerodynamic analysis of small horizontal axis wind turbine blades with winglets

Abstract

The aerodynamic characteristics of winglet added with small wind newlineturbine rotor blades are focused in this research work. The experiments and newlinecomputational studies are carried out to obtain the aerodynamic newlinecharacteristics on winglet added with small wind turbine rotor blades. Usages newlineof small wind turbines are limited due to their limitations in self starting, low newlinewind speed conditions and efficiency. The winglets added with small wind newlineturbines, is to reduce the self-starting requirement and to improve the newlineefficiency. The IT-PE-100 small wind turbine rotor developed by Soluciones newlinePrácticas-Intermediate Technology Development Group is taken as a newlinereference rotor for this research work, because of its dimensions and newlinesuitability of low wind speed region. Winglets are defined in six parameters namely cant angle, height, newlinetwist, sweep, toe and curvature radius. The present study focuses on winglet newlineheight and curvature radius which effects on small horizontal axis wind newlineturbine in order improve the power capture. Geometrically, similar five force newlinemodels made out of GFRP and five pressure models made out of newlineAluminimum with 1:5 scale of IT-PE-100 small wind turbine rotor are used in newlinethe wind tunnels for force and pressure measurements respectively. Among newline five rotor models, one was the base rotor model and four of the others are newlinewinglet added rotor models with variation in height and radius of curvature. newlineForce and pressure models are tested in a uniform flow in the wind newlinetunnels with a wind speed range of 4.74 m/s to 13.42 m/s. In the force model newlineexperiments, rotation rates and power generated are measured for all rotor newlinemodel configurations with and without load conditions. Pressure models are newlineprovided with 18 surface pressure ports located at suction and pressure sides newlineof chord wise locations at 0.3c, 0.6c, 0.9c for a span of 0.85 r/R and similar newlineports are provided for other two span wise locations of 0.9 r/R and 0.95 r/R.