Theoretical investigation of aerodynamics and design analysis of a HAWT with circular arc blade section

Abstract

A theoretical investigation is performed to determine performance characteristics of a Horizontal Axis Wind Turbine (HAWI) with circular arc blade section. The results are compared with those of HAWI having airfoil blade section. It is observed that the results of turbine with circular arc profile are comparable to those with airfoil blade section. With a view to diminishing cost of production and eliminating manufacturing complexity with airfoil blade section, the study is taken into account. The design of HAWI with circular arc blade profile is also carried out. The usual design uses the minimum value of the ratio of drag co-efficient to lift c0- efficient, but in this design maximum value of lift co-efficient (0.9 of maximum lift co-efficient) is considered to obtain optimum values of power coefficient and other parameters.This condition rather improves the power coefficient a little bit. The maximum value of power coefficient obtained by using circular arc blade profile is 0.38 while using conventional blade profile of NACA or Wortman, this value becomes around 0.40. The investigation is carried out by using only Momentum Theory and Blade Element Theory. Hence it may not be useful to apply for the multibladed wind turbine.