Numerical simulation of unsteady flow to show self-starting of vertical axis wind turbine using fluent

Abstract

The study of this paper is to show the effect of modified airfoil at the trailing edge on self starting of vertical axis wind turbine at low tip speed ratios using computational fluid dynamic analysis. A moving mesh technique was used to investigate two dimensional unsteady flow around Vertical Axis Wind Turbine (VAWT) model using fluent solving Reynolds average Navier-strokes equation. The model was created with airfoil modified from conventional NACA0018 to be flexible at 15° from the main blade axis at the trailing edge located about 70% of the blade chord length. Unsteady numerical simulations of the model were then conducted at low tip speed ratios, 0.1, 0.25, 0.75 and 1. The steady state performance of the model was also conducted at three different orientations of the airfoils using different wind speeds. The Simulation results were then compared to cambered airfoil NACA2415 which is self starting. The Simulation result shows that the modified airfoil has shown better self- starting performance both in unsteady and steady flow condition for the modeled turbine. © 2011 Asian Network for Scientific Information.