CAIRO UNIVERSITY
FACULTY OF ENGINEERING
ELEC. POWER & MACHINES DEPT.
FIRST YEAR
ENERGY CONVERSION
SHEET (5) Dr. Mahmoud Sayed
1- Wind turbine of two-blades type is designed to have its maximum power at
TSR=6 when the wind speed is 25 mph, if the blade diameter 100 ft. what is
the recommended speed of rotation in rpm?
2- A horizontal-axis wind turbine has a two blade is rated at 2 Mw and it is
installed in an area with a wind speed of 13 m/sec. , the coefficient of
performance = 0.32, gear efficiency = 94%, generator efficiency = 96%, if the
air density (𝜌air) = 1.29 kg/m3. Calculate the swept area of the blades and the
rotor diameter?
3- For the previous example, calculate the TSR and the torque on the turbine
shaft, if the rotor runs at 25 rpm?
4- A wind turbine rated at 3 Mw, if the wind speed = 17 m/sec. , with blade
diameter of 60 m. and the air density (𝜌air) = 1.29 kg/m3. Calculate the
coefficient of performance for the turbine. Assume gear efficiency and
generator efficiency each equal 90%?