Two-dimensional numerical simulation of the performance of orthopter-type wind turbine with S-shaped arc blades

Abstract

Abstract This paper evaluates the performance of an orthopter-type wind turbine with S-shaped arc blades using two-dimensional numerical simulations. For this variable-pitch vertical-axis wind turbine, each blade rotates on its own axis while all blades rotate on the main axis. This configuration ensures that the blades rotate around their own axes by 360° for every two-full revolutions of the main rotor. The central angle φ of an S-shaped arc blade was set to 60°, 90°, 120°, or 150°. The power coefficient Cp for a normal S-shaped arc blade is larger than that for an inverse S-shaped arc blade. The maximum power coefficient Cpmax for the normal S-shaped arc blade with φ = 90°-120° is suitable for an orthopter-type wind turbine. The inlet angle of the wind turbine θP was set 0°, ±5°, ±15°, or ±30°. The maximum power coefficient Cpmax was large for θP values of –15° to +5°. This wind turbine can achieve passive yaw control by means of a tail vane installed on the sprocket of main axis.