help me please
Explain the experimental procedure of C_1/C_2 -alpha curve determined through wind tunnel. The Better Wind Turbine Company wants to start marketing wind turbines. Their plans call for a turbine that produces 100 kW in a 12 m/s wind at a cold site (-22.8 degree Celsius, -9 degree F) with and air density of 1.41 kg/m^3. They have decided on a 20 meter in diameter, three-bladed wind turbine. The rotor is to have its peak power coefficient at a tip speed ratio of 7 in 12 m/s wind. The airfoil to be used has a lift coefficient of 1.0 and a minimum drag to lift ratio at an angle of attack of 7 degrees. You, as the new blade designer, are to come up with the blade shape as a starting point for the blade design. The design is to be based on the optimum rotor shape assuming that there is wake rotation (but no drag or tip losses). Find the chord length, pitch, and twist at nine stations of the blade (each 1 m long), assuming that the hub occupies the inner tenth of the rotor. Determine the rotor C_p assuming C_d = 0. Again determine the power coefficient assuming that the drag coefficient is 0.02, and that the aerodynamics are the same as the condition without any drag. How much power is lost due to drag? Which part of the blade produces the most power?
1). Experimental Procedure for determining Lift/Drag coefficient curve versus angle of attack.
Homework Sourse
