First of all, congratulations for this project! It’s awesome!
I had few questions and doubts:
Lenghten all the lines (on starting time) would increase the wind window and would increase the power generation in relation to the flying time. What do you think about it?
Why not using bigger size kites (foil/not foil) choosing to be “overpowered”(of course managing the opposite force applied by the ground controller)?
F
answers to questions and doubts
Sorry for late.
The power can’t be regulated only by lengthen all the lines. The mechanical power which the kite take from the wind should be increased only if the wind is weak. If the wind is strong we must decrease the power. We must design a system with the best power curve.
When the wind is weak, the power increase will be achieved firstly by flying at an altitude where the wind is strongest, compatibly with the regulatory permissions and the maximum tether’s length. Second, to maximize the power, we design the flight system control in a such way which allow the adequate:
a) kite angle of attack’s regulation and
b) kite flight trajectory such as previewed by Miles Loyd in 1984.
I’ve tried to write this flight system control in this flow-chart.
Can you check if it is understandable?
second answer
We cannot use bigger size kites because this is not controllable in stronger winds. We must achieve the best “power curve”, and using bigger kites we could have much power when the wind is weak but we can’t operate when the wind is strong. So, we must choose the right size.
For tower turbine usually the cut-in wind speed is 4-5 m/s and the cut-off is 20-25 m/s.
We will choose the kite size but also all other design parameters to achieve the largest power window. This should be more large than those for tower turbine because in the airborn wind eolic system, like our kiderwind, there are much more regulation chances. That is the operative altitude, the cross-wind speed, the kite trajectories.
