Random Engineering, Physics, ..., Concepts and Ideas

Sometimes I wonder if this tech doesn’t already exist… And if it does… Is it really a good idea?

24 posts were merged into an existing topic: Slow Chat

Stuff Made Here breaks down Automatic Bow

Have been told that y’all like this kind of stuff. Spoke tension meter for bikes

How to Use the Park Tool TM-1 Tension Meter & Wheel Tension App

Everything You Need To Know About Wind Turbine Blade Aerodynamics | Engineering with Rosie Live ep 7

Here he mentions vortex generators, trailing edge serrations, and gurney flaps are made of Acrylonitrile styrene acrylate - Wikipedia

3d Printing ASA For Beginners (Ender 3) Most Underrated Filament?

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The reason they use “winglets” on airplane wingtips and not wind turbine blade tips is:

  1. As they pointed out, the aerodynamic effective advantage of a winglet versus just making the blade or wing longer is about the same.
  2. Airplane wingspan is limited by ground taxiing traffic patterns and clearance between aircraft, so for that application, the winglets make sense and the advantage is better clearance from other aircraft on the ground.
  3. Unlike airplanes, the major force on a blade tip is centrifugal force. Imagine the whacky centrifugal forces on a blade tip caused by a winglet protruding toward the wind, trying to bend outward. The bending moment would want to delaminate the composite structure on the inside of the curve, while pushing the blade back toward the tower. It would take a lot of extra material to handle those loads. Then the whole blade would have to be stronger (heavier, more expensive) to support all that extra weight at the tip. So for wind turbines it is better to just make the blades longer.
    Whale bumps? I guess we’re still waiting, after 1000 magazine articles. Discussed on the old forum for maybe ten years. I don’t have to tell you who on the old forum thought they were a great idea. Some people can only reason as deep as a slogan that will fit on a bumper-sticker. In the case of whale-bumps, the single-word slogan was “biomimicry!” As discussed, from a layup standpoint, they would have to be an add-on, but without any real advantages. Whalebumps - sounds like a cellulite chafing issue for thunderthighs. Be careful what you believe. There are a lot of crazy half-truths floating around out there. :slight_smile:
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Airshaper are always giving out explainer materials online.
Here’s a good list of their recommendations for aerodynamics software

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Check the size of their bols
Massive bols
https://m.facebook.com/groups/171673702965998/permalink/2543374475795897/?sfnsn=scwspmo&ref=share
They’re claiming 65m in diameter
Looks more stable than most

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Looks as if some flexible kites have no limit of scaling. By approximate calculations according to the image, we would have an inner diameter of about 40 m, i.e. a total annular surface of about 2000 m².

Perhaps this bol kite type could lead to gigantic rotary architectures, including Daisy type.

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11 posts were merged into an existing topic: Slow Chat

There are material limits on scaling soft kites.
If I remember @kitefreak correctly…
Weight per square metre of material has to increase with higher wing loading of larger kites. Unless you break them out into cells which use shared loadpath lines to create an overall larger kite form from the cells

Yes, and this point has already been discussed.
https://www.researchgate.net/publication/290775361_Ram-air_Wing_Design_Considerations_for_Airborne_Wind_Energy
Page 532:

The development originated as an Advanced Concept Technology Demonstrator research program from Natick Soldier Systems, whereby iteratively heavier weight requirements were levied (0.25 ton, 1 ton, 2.25 tons, 4.5 tons, 13.5 tons, and finally 19 tons). The wing sizes were 36 m2, 102 m2, 250 m2, 350 m2, 900 m2, and 1,040 m2, respectively.

That said, some shapes (such as bowl kites or parachutes) could perhaps suffer a lower weight penalty when scaling up.

7 posts were merged into an existing topic: Slow Chat

World’s LONGEST string spinner!

https://www.reddit.com/r/space/comments/uke6yb/chinese_rocket_startup_deep_blue_aerospace/i7oo6ma/

https://www.reddit.com/r/AerospaceEngineering/comments/un6qbl/aircraft_wing_structural_design

How to discharge a cloud before it comes over your kite field

OTV8 drone stabilisation concept

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Here’s a video of wind power test clips over the last 10 years at Pacific Sky Power Clean Energy Projects at Pacific Sky Power - YouTube

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Adaptive Functional Structures inspired by Insect Wings | Talk

Natural world of insects

Best STOL Wing Design Ever?!?

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I tried to find the mentioned videos in reference [1] but couldn’t, apart from maybe this: cerf volant outdoor - YouTube

A mention of “whirling arm” in the paper, and a video of it: George Caley - The British inventor of the aeroplane, previously linked.

Here it is used to test a kite plane: TX-8.2 Flight - YouTube. And new videos from the same channel of a kite plane riding up and down a tether: WindiVator 1.0 - YouTube and a kite plane controlled by flight software: - YouTube

Related (control line flying; torqueless rotors): Random interesting links - #16 by Windy_Skies

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That SandyDoggy YouTube makes some brilliant experimental glider kites