Peter Sharp indicated that (without lifting gas in an inflatable version) a central large disc was required, as for any rotating Magnus effect kite like on
But perhaps end discs could be enlarged as for the Savonius-type kite on
I read somewhere that indeed a rough surface would be preferable. There is also the presence and size of the discs, the aspect ratio…
I have a question: would an inflatable Flettner rotor (which remains a lighter AWE option) like Omnidea, be as effective as a rigid rotor? Omnidea tests showed good performance but at a low tangential rotation speed (well below 10 m/s), and also a relatively high power consumption in regard to the low tangential speed.
I’m also concerned that wind pressure will hollow the balloon, putting pressure on it to hinder rotation.
Peter Sharp is really an expert in Flettner and (of course) Sharp rotors.