Open-source Höhenwindkraftwerk (Drachen) in Freecad - FreeCAD Forum (open-source airborne wind energy project in freecad)

[Windy_Skies]

He starts off with just drawing things in the CAD program but after page 40 or so also does some modest testing. Not enough though. He reminds me of every beginning inventor too in love with his idea and drawing it in CAD to test if it actually works. He does seem to accept feedback and new information so if he doesn’t give up he may get somewhere in a number of years. He has made some progress already, with the help of the other forum participants.

The most obvious problems with the design to me are, I think he assumes the wind has a fixed 1Hz frequency of gusts and lulls, even at height… and he seems to want to use a 7 kilometer rope to lift a weight 1.3 meters 60 times a minute.

Some links and quotes from the thread:

Chassis Design of a Control Pod for a Kite Power System
Master Thesis Report at SkySails GmbH, Hamburg for Royal Institute of Technology, Stockholm.

https://forum.freecadweb.org/viewtopic.php?f=13&t=45280&start=410#p403630
The experience of your friend is confirmed by this radar measurement.
A band of turbulence runs in the area between 2–3 km in altitude.
Source:
http://www.kyoto-u.ac.jp/cutting-edge/e … age13.html

Open-source Höhenwindkraftwerk (Drachen) in Freecad / Windpumpe - Page 47 - FreeCAD Forum
during the capacitor test it became clear that without a battery only a feed into an existing network is possible. a rechargeable battery is required to implement off-grid (island operation / diesel generator replacement / mains-independent). i have a ni-fe battery that is over 80 years old and still has 100% performance. these batteries have been proven to last for at least 120 years and are insensitive to deep drainage, overcharging and frost. They do not need any charging electronics and are the most environmentally friendly compared to all other batteries. in terms of service life, they are also the most affordable of all batteries.

Nickel–iron battery

Open-source Höhenwindkraftwerk (Drachen) in Freecad / Windpumpe - Page 51 - FreeCAD Forum
in order to illustrate the functionality as clearly as possible, i shot a short video.

Open-source Höhenwindkraftwerk (Drachen) in Freecad / Windpumpe - Page 55 - FreeCAD Forum
The walls of a container are not made of corrugated iron - that sounds like 0.5mm - but rather of trapezoidal sheet metal. I guess that they are 2mm or more thick. And if you then imagine a container ship like this in a storm, with 6 container layers on top of each other, then they should also be able to withstand a lot of lateral forces, even if you consider that they are then stiffened diagonally.
I found a page here that does some calculations. I think that the forces created by the kite are small compared to the forces created by the weight of a flexitank.
https://www.tis-gdv.de/tis/containe/fle … chung-htm /

Open-source Höhenwindkraftwerk (Drachen) in Freecad / Windpumpe - Page 57 - FreeCAD Forum

https://www.youtube.com/watch?v=rcJ3pfeQaZc

https://forum.freecadweb.org/viewtopic.php?f=13&t=45280&start=590#p408366
Ja, ist aber reine Zeitverschwendung.
Die knapp 60 kN Bemessungslast enthalten ja bereits den dynamischen Anteil durch den Böenraktionsfaktor. Das wird so gemacht, um die Bauteilbemessung statisch durchführen zu können, weil ein genauer dynamischer Nachweis sehr aufwändig ist. Dazu kommt, das für den Dynamiknachweis wesentliche Parameter unbekannt sind (z.B. Systemdämpfung). Beim Nachweis kompliziert geformter Bauteil (z.B. Rohrknoten, Verdrehschäkel usw.) müssen die statisch zulässigen spannungen abgemindert werden. Der Grad der Abminderung hängt von der Anzahl der Spannungswechsel ab, grob gesprochen also von der mittleren Frequenz der Windturbulenz. Stichwort Wöhlerlinie. Siehe hier, S.5:
https://core.ac.uk/download/pdf/19127289.pdf

Open-source Höhenwindkraftwerk (Drachen) in Freecad / Windpumpe - Page 65 - FreeCAD Forum
the current version can now be downloaded from thingiverse (without registration). because fcstd cannot be uploaded, i had to change the ending. before opening please change it back to .fcstd.

awe open source by thomas_neemann - Thingiverse

Open-source Höhenwindkraftwerk (Drachen) in Freecad / Windpumpe - Page 70 - FreeCAD Forum
Here’s an experiment:
Parachute approx. 5 m in diameter under constant internal pressure of 1000 Pa.
The ropes are modeled as ribbons, then it goes with 2D elements.
The deformations are very large, so calculate non-linearly (in the next step …)

parachute.FCStd

Mooring simulation with DualSPHysics (SPH on GPU)

SkySails Power: Operation of Airborne Wind Energy System

EnerKíte Flugwindkraft in einer Minute erklärt

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New to me, and looks more promising to me, Horst Bendix:
New inland wind turbine opens up the high winds - Onshore wind energy urgently needs innovations that multiply the annual energy yield per plant and location. A contribution by Horst Bendix.

BUNDESAGENTUR FÜR SPRUNGINNOVATIONEN

Open-source Höhenwindkraftwerk (Drachen) in Freecad / Windpumpe - Page 75 - FreeCAD Forum
I only noticed the project in passing. As I see it, the initiator of the user is “thomas neemann”.
Just came across the following article.
https://www.heise.de/news/Agentur-fuer- … 09254.html

https://www.sprind.org/de/laufende-projekte/bendix/