| The current popular blade design theory is described in this article, mainly including Simple Windmill theory, Glauert theory, Schmitz theory and Blade Element-Momentum theory,and cmpares the differences and similarities. Aerodynamic performanc using Blade Element-Momentum theory with various amendments to the theory. With these theories ,developed a corresponding program with C # programming language.The part of blade design includes input of the initial parameters, Simple Windmill theory, Glauert theory, Schmitz theory , Blade Element-Momentum theory and a database of a number of coefficient airfoil lift and drag (only small angle) which is established by SQL 2005.Blade aerodynamic performance is mainly based on Blade Element-Momentum theory and takes into account the wind shear, tower shadow effect, yaw effect and cascade effect. Aerodynamic calculation program can establish a new project, open a project,save a project, and calculate the aerodynamic performance of blades with equilibrium wake model . The results were be compared with the GH Bladed3.81 software.Designed 100W blades respectively with Glauert theory, Schmitz theory and Blade Element-Momentum theory and campared the power with car experiment.It was found that these types of theoretical design have a big difference with the actual shape,so the blades must be repeatedly revised that can actually used. Secondly, the blades designed by Glauert theory whose generated power and wind energy utilization coefficient are higher than Blade Element-Momentum theory, but it presented different aws of dirrerent loads.This article also did the car experiment to know different tips to the power effects and it was found that the blades with symmetrical arc tip are better than the arc asymmetry tips and no arc tips. |
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