Kites like parasails or powerkites could perhaps experience some sorts of hoop stress, due to wind force on their curved concave surfaces.
Wind force would be somewhat like the pressure in blimps, and would also be a limiting factor, just as scalability would be limited for both due to hoop stress in a broader sense at least concerning soft kites.
All this is hypothetical and can be wrong, but perhaps might deserve some study.
In the end one might come to the conclusion that mass and volume scales cubic, no mater the design⌠rigid or flexible doesnât matter.
I didnât dare to say it. It is too true. Both blimp and soft kite volumes scale cubic, parachutes or powerkites being bulky.
When blimps become larger and larger, their mass increases such that even large rigid airships become lighter.
Why would not be the same for flexible kites, knowing that AWE use at large scale could involve dimensions like airship dimensions? Flexible kites are far to reach such dimensions.
And perhaps we will see a fairly consistent relationship between the power that a rigid or flexible AWES (in respectively similar materials) would develop and their necessary mass: if they only operate in light wind, their mass will be the same as if they are smaller and only operate in stronger wind, somewhat like lightweight wind turbines operating in light wind compared to smaller standard wind turbines operating in stronger wind.
Surely a single skin kite scales linearly. I could just as well build a number of small kites and join them together.
Concerning scalability, I donât think there is a major difference between single skin kites and ram kites.
Itâs just a hypothesis on my part, but perhaps the scalability curve could look like an asymptote? A little more than linear at the beginning, and much more than linear at the end.
A blimp (flexible airship) becomes increasingly heavy as he grows. âWhy Blimp Technology Doesnât Scale Up Wellâ could perhaps apply to soft kites.
Even for a single skin kite there is no escape. If you keep the design the same (number of bridles etc) will need to increase fabric thinkness linearly as well to manage the stress in the fabric.
You can increase the bridle levels, but thatâs not really scaling the same design. With more bridles the smaller kites could use a thinner skin, thinner bridles. Itâs just not practical to manufacture.
Iâm sure we can find a convenient way of joining kites together and perhaps we can use Shapewave technology to attach the bridles to the fabric.
Sure. Some designs is lighter than other. Iâm not arguing against that.
If you can sow multiple kite together. It think itâs more meaningful to consider that a different design than the original kite.
Generally you canât just sow many together. There will be some complications, which is the reason why the original kite wasnât made of many small kites in the first place
This corroborates the measurements of kites of different dimensions. We will therefore indeed have a mass increase slightly above the surface area increase (squared, so linear when we consider that the mass/m² does not increase with the surface area), and not above the volume increase (cubed) like blimps. Soft kites benefit from their bridle which mitigate the requirement of thicker fabrics excepted the reinforcements.
I guess you are right; larger blimps would have less curvature thus more tension on the cloth to maintain the same pressure difference inside/outside. Which would indicate thicker skin. I think quite likely you could arrive at cubic scaling of blimp skin weight, but then lift of a blimp also scaled cubically, because lift is by volume and not by wing area as we are used to thinking in kitesâŚ
The question really is - would you make a blimp that is so large that skin mass is a driving design factor?
Yes, but my question is if this can apply to kites, in a way of another. I think that for kites, the bridle is a major element which strongly mitigate scale mass penalty.
Ahhh @gordon_sp
Is this where Network Kites topic comes in?
As @aokholm points out
You have consider a network of standard kites as a being new designâŚ
@kitefreak was an advocate and maker of networked arch kites.
But we dare not mention him for he will undoubtedly complain and spam us all.
Arch kites bridle in to a shared load line tether
This larger main tether forms a half loop catenary (for above anchor level flying over a flat field) between two anchors.
Not at all sure how that shared line leaves the hoop stress calculation, but with the kite skins being fairly static thereâs not a lot of wing loading , so even with all the extra kites added to one lineâŚ
The arch lines are not easily overloaded