Based on the phenomenon of harmonic oscillation of a restrained kite, I wonder what the frequency and amplitude of oscillation would be if the kite size was dramatically enlarged. Can the amplitude be enhanced by continuous adjustments in the lengths of the tethers? My feeling is that rather than tapping the power of oscillation we should consider it a form of crosswind flight. If turbines, parotors or daisies are hung from the kite, then crosswind action will manifest itself as an increase in effective wind velocity on those devices. Since power output varies with the cube of the wind velocity, a 10% increase in effective velocity will result in a 33% increase in power output.
We agree that scale-up of single skin or LEI kites is more favorable than rigid wings. However, according to Peter Lynn, larger kites become more unstable. Does this apply to restrained kites? I think not.
Using this method we would eliminate the necessity of kite steering control systems. We might be able to move the kite at higher velocities than can be achieved with kite steering units. This would dramatically increase the available power.
I see this (if I understand what you are saying, I am imagining a Kiwee with an oscillating lifter) as not much different than what Makani is doing in theory. The lifter kite is pulling the turbine around to make it produce more electricity. The lifter kite will have to overcome considerable drag to accomplish this. So you are making use of the kite area more efficiently. BUT - the rig will necessarily fall further downwind, so the kites will have to be dimensioned for this.
Sure, you could design a rig like this, and sure it might be a good idea.
Oscillating movement can sometimes be more stable than more static flight (ie the oscillating kite might be less prone to drift off to either side).
I would assume oscillation with larger scale would significantly slow down turning rate and this lower oscillation frequency. This in turn might require longer tethers.
Seems like some testing would provide a lot of insight into the situation.
My idea of restrained crosswind flight is not the same as conventional action. With my proposal, the kite remains vertical at all times and is only moved from side to side by the action of the 4 auxiliary tethers at the corners of the kite. Why is it necessary to rotate the kite? Rotating the kite may cause problems with the cable drive. I intuitively feel that the floating generator design of Kitewinder will be problematic for systems greater than 1Kw. This should be discussed in another topic.
I @gordon_sp. I feel I already seen your name somewhere, did we already met? Kitewinder tech is ground gen. We only have a propeller up there with a right angle. That is why I think a makani style awes with Kitewinder rope drive could be great for crosswind
I just had a look from my phone, looks really complicate. I was thinking of a wing like makani but instead of transmitted to ground with electricity, you could transfer the rotation of the blades through a rope drive. Thus you do crosswind, ground gen, no réel in reel out. To me it looks to be a great compromise