Paper Title
END PLATE ENHANCEMENT OF LIFT COEFFICIENT OF THE VERTICAL AXIS WIND TURBINE BLADE

Abstract
The addition end plates to aircraft wings has proven advantageous as a method for controlling wingtip vortices. This technology was adapted to vertical axis airfoil shaped wind turbine blades. In this study an investigation of the variation of lift coefficient at low wind speeds was undertaken. Experiments were conducted with and without end plate attachment to the MI-VAWT1 airfoil. Tests were conducted at angle of attack for 0, 5, -5, 10, -10, 15, -15 degrees in a suction type wind tunnel. The wind speed was varied for Reynolds number ranging from 3.32 x105 to 9.64 x 105. Pressure taps on the airfoil skin gathered the stagnation pressures which were converted to lift coefficient values. The results indicated that the addition of the endplates increased the lift coefficient at all angles of attack over the range of Reynolds number tested. Similar trends were observed with and without endplate. The flow regime boundary layer separation point advanced toward the leading-edge with an increase in the angle of attack up to ±10o. As the angle of attack increased above ±10o the stall angle was approached. This resulted in the separation bubble bursting, which created a suction peak and the lift coefficient decreased. Keywords - Lift coefficient, Endplates, Vertical axis wind turbine, Airfoil.