Design of a Vertical Axis Wind Turbine DMST method Report

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Analysis of a vertical axis wind turbine with the application of the Double Multiple stream tubes method 1 Contents 1 Introduction 3 2 Initial data 3 2.1 Motivation for the DMST approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Simplification for the DMST method applied . . . . . . . . . . . . . . . . . . . . . 4 2.3 Correction adopted for the model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.4 Discretization procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Result discussion 5 3.1 Attack angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Reynolds number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.3 Lift and drag coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.4 Tangential and normal coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.5 Induction factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 Conclusions 9 2 1 Introduction The aim of the project is to evaluate the performances of VAWT (2 blades H-type) where the geometry is given. The performances are found trough the application of the double multiple stream tubes methods (DMST). At the beginning a sensitive analysis is performed to figure out a good number of stream tubes, after the dependence of geometric and fluid dynamics parameters as a function of the tip speed ration for a given wind velocity is discussed. At the end the performances of the machine for different tip speed ratio and wind condition are computed. 2 Initial data The geometric design of the machine is given by the following relations: D(i) = 3 + 0.17 · (19 −i) (1) c(i) = 0.05 · D(i) N p (2) H(i) = 2 ·D(i) (3) where i is the group…