Wind

Question 1

Betz Limit

Answer 1

(see equation)

Question 2

Engineering Condsiderations

Answer 2

1. Make the rotor light and strong with consideration to material fatigue
2. Rated power is the maximum power at which the machine will run continuously
3. Capacity and capacity factor is the ratio of annual power output to that which the machine would have output had it been rated at that power throughout the year
4. Less expensive to have one large machine producing the same output as a number of small ones

Question 3

Wing Planform Considerations

Answer 3

1. To ensure that the optimum power out put occurs throughout the length of the blade, decrease twist as r increases
2. Wider blade at the root, narrow at the tip is an attempt to harvest maximum power everywhere in the swept disc area
3. Aerofoil shape to maximise Lift while keeping Drag low