EXAMPLE 3.2: In a blade with an airfoil profile the total aerodynamic force acting on the blade when wind speed is 25 ft /sec is 50 lb. Th e lift coefficient for this airfoil at the given angle of attack is 0.95. For the same angle of attack, if the wind speed changes to 40 ft /sec, find the lift force on the blade. EXAMPLE 3.3: A turbine has three similar blades, each with the profile of the airfoil as in example 3.2. Under the operating conditions the lift coefficient is 0.95 and the driving torque in the shaft is only due to the lift force. If the wind speed is 25 ft/sec and each blade is 22 ft long, find the torque generated in the shaft.