Effects of Blade Root Dimensions on Physical and Mechanical Characteristics of a Small Wind Turbine Blade

Abstract

Small wind turbines have the potential to act as a complementary clean energy source to solar PV, especially during nighttime. However, the generally less attractive payback of small scale wind turbines has restrained its widespread application, and one way to improve their cost effectiveness is by improving the efficiency, for which blade design is a crucial factor. The blade design is a complex but interesting process and still demands continuous research at various stages. This research paper presents the effect of flat rectangular root dimensions on blade mass, stresses, strain and deformation for a fixed pitch, horizontal axis small wind turbine blade of 2.5 m length. For the three considered variables root length, width and thickness, four levels of dimensions are selected for each which yields 64 blade models. A total of 16 blade models with different root dimensions are finalized through the Taguchi method and investigated using finite element analysis. The effects of these variables on five characteristics, namely: blade mass, stresses in the blade main body, stresses in the blade root and connecting portion, deformation and strain are studied. Analysis of variance is carried out for all these independent and dependent variables. The results indicate that the thickness, length and width are the most, intermediate and least influencing variables respectively, and cause significant changes in these five characteristics of the blade.