Rotary Kite Turbine Development
Roderick Read, Windswept and Interesting Ltd
You can get a copy of my slides hereā¦
I wish Iād been a bit better at rendering 3d before the conferenceā¦ Might have put this in
A kite turbine with the lines enhanced
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Hereās something which hasnāt been mentioned a lot about Kite Turbine stacking.
They have a weird relationship with cos cubed
Normally in AWES as we increase elevation, we have less disk presented to the wind.
Makes sense, the blades (rotor plane) are tilted.
But what happens if you have stacked your rotors one on top of the nextā¦?
At 0 elevation, only the first rotor see clean windā¦ So we can discount the occluded areas from the downwind rotors.
As we increase the elevation the total amount of rotor disk exposed to the wind increases, up until around 31 ish degrees in this configurationā¦ oh and on review, another maxima grows at higher elevation as the disks uncross
See
There are subtitles to explain whatās going on.
Also
There is a different calculation being done for the occluded areas being projected down (top area only) vs the areas being projected back (full exposure counted) Which system will be better? Why?
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If you give a number to the power in an occluded area, you can optimize for power. Anyways look like something that may want to be run through CFD
Also longer tethers will helpā¦
But itās always more complex than thatā¦ This is AWES
altitude effects, line drag, torsional rigidity loss, ground use requirementsā¦
This is 100% optimal already because you can bodge it in a garage and fly it & smile at it in a short time
This is something that real-life data would help with. So also something that eventually will solve itself
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I couldnāt resist a bit of cleaning (the househusband side of my work taking over again)
The model is a lot neater now and easier to follow
In better HD and you have a commentary.
Iāve had a go at modelling a Kite Turbine in Julia.
When I say I had a goā¦
Anyway
Quite a bit still to work on butā¦ might be useful one day
gone through a massive rewrite already (not uploaded yet butā¦)
It looks so funny
This model has improved significantly
Anyone up for reviewing this work so farā¦?
As you can see in the stats the beams in the spec were waaay too skinny
This report gives you more detail on scalingā¦
TRPT_Ring_Scalability_Report.docx (870.3 KB)
You can play with it here
https://github.com/rodWindswept/KiteTurbineDynamics.jl
I do have concerns with some elements of the description
Just like the kites - most of this is - over my head
e.g. in the following paragraph from the report the phrase āis stretched by the twist geometryā??? bit wary of that ā¦ but Iād have to dig so far into the
maths
2.3 Tether Tension: Elastic Stretch Dominates
An important finding from the ODE simulation is that the tether tension at rated operation is T ā 2333 N per line, far exceeding the ~111 N predicted by a simple torque-balance model. The dominant mechanism is elastic stretch: each Dyneema tether (EA ā 707 kN) is stretched by the twist geometry, with chord length c = ā((RĀ·Ī“)Ā² + L_segĀ²) > L_seg giving a tensile strain of ā 0.4% at rated. This elastic tension scales with rotor radius as T ā RĀ² (since EA ā dĀ² ā RĀ² and RĀ·Ī“ / L_seg is constant when Ī“ is fixed at the optimal twist angle).
it does twiddly round spinny stuff now though
Thatās a bonus - makes it much prettier
OMG itās fast - already addressed those and a few problems and revised and commit pushed to git.
And now done a stacking scalability sweep
TRPT_Stacked_Rotor_Analysis.docx (622.5 KB)
Been working on various improvements
Been able to run some more analysis
TRPT_Conical_Stack_Analysis.docx (1.3 MB)
TRPT_Ring_Scalability_Report.docx (870.7 KB)
TRPT_Stacked_Rotor_Analysis.docx (625.5 KB)
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Starting to query the model for twist relationships and different control mppt options
Long way to go
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A new report, but clearly there needs to be more consideration of the likes of lift line tension effectsā¦ Was run previously on another pc but need to incorporate that soon
TRPT_Twist_Analysis.docx (439.5 KB)
A report on different lift options.
I had run a similar analysis on another pc which favoured rotors more so..
Take this with a large pinch of salt and feedback on the obvious flaws
The referencing is dooolally as well
TRPT_Lift_Device_Analysis.docx (962.8 KB)
Stillā¦ this is an interesting document
OK, starting to get somewhere more real, we have a dropping kite
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Bit more realism injection needed
Still got issues
OK, a bit better now we have sag on the TRPT too but itās still not got the collision detection solid body ā¦ That could be a lot of computes
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Going to run a power curve sweep and some more analytics overnight.
Got this report earlier but I think itās about to be superceeded.
TRPT_FreeBeta_Report.docx (947.2 KB)
Annnd another report generated by the simulation
written by an AI
So anyone believing this is a deluded fool obviously (Iāve seen a few mistakes in it)
Buttttt itās getting somewhere
TRPT_KiteTurbine_Potential.docx (432.4 KB)