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

Windy_Skies · July 17, 2020, 2:05pm

https://www.reddit.com/r/Fusion360/comments/hsv3g1/airfoil_tools_for_fusion_360_new_addin/

Some interesting stuff in the linked Autodesk forum post:

I’ve done some meta-analysis on the results of my particle-swarm optimizer which myself and other die-hard optimization freaks might appreciate knowing - as you may know, I’ve had 180 CPU cores across many (expensive) machines working full-time on this since Covid-19 imprisoned me at home (and also fewer cores, not always full-time, since 2012 too). I optimized for Reynolds Numbers from 50 to 100,000,000 - so I am now able to plot the CL/CD for all of the best-performing foils that my code has “birthed” (it’s a genetic optimizer):-

Which basically points to there being a “sweet spot” at around Re 7,000,000. What this basically means in laymans terms, is that if you are (like me) working on designing an underwater turbine to harness ocean currents, you’ll want a root chord length of about 3 meters designed to turn at about 4 knots to extract the most possible energy with the least annoying torque-effect from the current.

Or, more generally, you want “longer chords” and “faster speeds” whenever you can, to try and get that Reynolds number up as much as practical, since you can see in the chart - the performance efficiency line just gets better and better as you go higher (maxing out from Re 7M).

Windy_Skies · July 18, 2020, 4:22pm

I started noticing that people were using inertial sensors ( inertial measurement unit ( IMU )) in projects. They look to me to be almost mandatory in AWE.

Here is an intro, I think:

Windy_Skies · July 19, 2020, 5:57pm

Windy_Skies · July 22, 2020, 7:24pm

Rodread · July 24, 2020, 9:32pm

Weirdest Kitesurfing inventions
Made me smile

Windy_Skies · August 3, 2020, 3:22pm

Windy_Skies · August 8, 2020, 8:46am

Here is one very simple way to wind a line on a drum evenly, a rotating threaded rod that a pulley rides up and down on: World Kite Altitude Record 2014. You can see pictures and video of it working a little later on in the video. Explanation of setup here from earlier attempts: 2012 kiterecord

Any other implementations or methods?

Windy_Skies · August 10, 2020, 10:14am

My robotic basketball hoop wont let you miss – Stuff Made Here

Here the backboard moves. Also check out the links in the description. Books on real time collision detection and computational geometry, among others.

How I made a basketball hoop that always goes in – Stuff Made Here Here the backboard is a special shape.

See blindfolded with an iPad + LiDAR + tactile interface – Stuff Made Here

Rodread · August 13, 2020, 9:03pm

OK very random link but…
Got to look after the state of your airborne support cable networks
Check out the Scott Manley report on an accident at the Arecibo radar telescope

The rigging is a bit like stadium fly cam rigging.

I love thinking of kite power system configuration in telescope focus terms … e.g.
Can we instead of stretching a lens out long … Array lens elements and reflect the energy for a more efficient machine?

Windy_Skies · August 18, 2020, 4:29pm

Designing and Building the Automatic Kite String Reeler-Inner – Matt Bilsky

Automatic Kite String Reeler-Inner - Matt Bilsky

CROSS WINDING OF YARN PACKAGES
The research reported in thesis was undertaken to realise a random winder capable of detecting the occurrence of ribboning, and taking the ribbon breaking action at these precise times, and thereby achieve ‘active’ ribbon breaking. Such a winder was realised by the addition of suitable transducers to a standard random winder, which could be controlled by a PC. Winding trials carried out using this equipment established the effectiveness of the concept and also the greater freedom from ribboning the method achieved in comparison with other available methods. Unwinding trials carried out by suitably modifying the winder for measuring yarn unwinding tension were also used to establish the effectiveness of active ribbon breaking.

He has more videos about different subjects.

Single End Sizning for Cotton Warp - Rabatex
Note how the thread is threaded through those spring-loaded eyelets to keep tension even, among other things.

Windy_Skies · September 20, 2020, 9:29am

https://books.google.com/talktobooks/query?q=rope%20dynamics&filters=10

Windy_Skies · January 29, 2021, 3:05pm

Windy_Skies · February 9, 2021, 9:22am

Windy_Skies · February 16, 2021, 7:15pm

dougselsam · February 17, 2021, 4:35am

A photo of a dust storm in the Mojave Desert of Planet Earth taken from 8200 feet elevation at the top of Mountaiin High Ski Resort near Los Angeles, California, yesterday:

dougselsam · February 18, 2021, 2:38pm

Later that day: Damage to a roof on a ranch property below.
I stopped to water some trees on my way home from skiing and found a lot of roof damage. I’m still repairing it. We get winds here that would make national news anywhere else. We just put up with it.

Rodread · February 18, 2021, 5:55pm

Nah
You wouldn’t get approval for flimsy felt tiles like that here
Slate, concrete or turf

dougselsam · February 18, 2021, 6:40pm

Hi Rod: Around here they really need to have the lower edge bonded to the row underneath using tar-based roofing cement, then they can hang in for the long haul. In a neighborhood they would be fine, but out here in the vast open regions, especially on a hill, they need extra attention when being installed. Soon it will need to be re-roofed. I might do it myself so this does not happen again. may even add another layer of plywood.
My main residence and shop have over 12,000 square feet of roofed area, and yes, it is concrete tiles. They still blow off sometimes. We’re technically in a mountain pass, at 3600 feet elevation. Like living in the sky. Probably similar winds to what you experience, or maybe yours are even worse.
Here’s the view from the roof of the backyard and the mountains where we ski. Everything looks brown cuz it’s winter. In a couple months it will be all green with wildflowers and butterflies! Very exposed to wind on this hill.

Tom · February 21, 2021, 3:13pm

Rodread · February 22, 2021, 10:19pm

I did like those flappy birdy pictures
However
This is a proper random yet definitely airborne wind energy ish kinda sorta thing