Aerodynamics characteristics of a vertical axis vane type wind turbine

Abstract

This research work has been carried out to study the aerodynamic characteristics and to analyze the effect on an equally spaced vertical axis four, five and six bladed vane type rotor. The aerodynamic characteristics i.e. torque coefficient, drag coefficient etc. of vertical axis vane type rotor have been studied in this present research work by measuring the pressure distribution on the blade surfaces at various rotor angles. The experiments have been carried out at a Reynolds number of 1.65 x 105 in a uniform flow jet produced by an open circuit wind tunnel. The pressure measurements have been made at 8 tapping points on each blade of the vane rotors. Pressure on the convex and concave surfaces have been measured for every 100 interval of rotor angle up to 3600 angle of rotation. The data obtained experimentally has presented in terms of non-dimensional coefficients. To calculate drag force and torque in non-dimensional form, computer based software has been used and the output have been subsequently plotted and analyzed. Aerodynamic characteristics on individual and group of four, five, six blades have also been determined in the present work. A quasi-steady approach has been applied for studying the dynamic performance of the rotor at different rotor angle using the static drag and torque coefficients. Power coefficient versus tip speed ratio curve for four, five and six bladed vane type rotor has also been drawn. Power coefficient versus tip speed ratio of the present measurement and the previous researcher's works has plotted on the same graph for comparison. This method results in a reasonable agreement with the previous measurement.