Computational Analysis of Vertical Axis Wind Turbine with open-able airfoil

In this paper, NACA0018 airfoil is proposed to be open able at low tip speed ratio to work as drag device and then be closed to take the normal blade geometry of the airfoil at higher tip speed ratios to work as lift device. A moving mesh technique was used to analyze 2D unsteady flow around VAWT modeled with airfoils opening angles set to 60, 45, 30 and 15 degrees from main axis using CFD solver fluent solving Reynolds average Navier-strokes equation. Numerical simulations of the models were then conducted for each of the opening separately at low tip speed ratios. The steady state performance of the models were also conducted at tip speed ratio equal to zero. The simulation result shows that the generations of negative torque increases with the increase of opening angles and vice versa.