Magenn’s design uses torque of its turbine settled arround the balloon. Omnidea’s design uses lift.
The tennis ball Newton himself observed exhibiting Magnus effect is centuries-worth of “highly evolved”. Just make the WECS fuzzy.
What poorer aerodynamic principle is there to throw AWE investment at? So weak its safe, until everyone dies because it was so ineffective.
Between the cruel limits of Magnus concepts and Rigid Wings, the Power kite positions as the Goldilocks engineering choice.
I met Ferguson at HAWPcon09. Incredibly ignorant of aerodynamics, but very media-savvy, he had hauled in 33M USD during his Magnus career, starting with a failed airship and large “insurance fire” that destroyed the full-scale prototype. Possibly the number one aerospace con-man of all time, IF he had any awareness of his profound incompetence, which he never gave a clue of.
It keeps happening that millions of AWE investment is spent on poor prospects. Let these failures pay off by proving what stinks (and sort who predicted what).
How would you conment the C_L with values > 10, if magnus is a very weak effect, while the powerkites have 1-1.5?
Magnus effect is quite strong, favoring compact wings, powerkites favor large surface area due to simple and lightweight design. Both approaches might have their merits
Lift coefficient about 7 or 8 implies a spin ratio of about 4, so a powerful motor to rotate the balloon. For Omnidea’ balloon the motor is about 500 W (for about 2000 W generation) for a spin ratio of 2 with a wind speed about 5 m/s. All precise data are on their website and documents.
High Cl is negated by high actuation force, the energetic cost of skin-friction by motoring the fast spin. It takes a lot more energy to make a sport ball curve than just setting regular wing AoA.
I would better believe the high Cl number was serious if I had any real-life experience with such performance with actual aircraft.
Let the KiteMill Investor prove me incorrect
Ok. That sounds like a potential showstopper. I was not aware that motor power would be so high…
Magnus Effect motor power can be derived from sport data by the average difference in velocity in a baseball straight-pitch and curveball pitch.
Kite AoA actuation can be balanced from handles by “fingertip” force, then left in place at zero power-load.
We can see that Magnus WECS have a high zero-point-energy (energy required to activate system) before any free-energy is available for extraction. Similarly a performance glider requires greater zero-point-energy than a power kite to get going. There is a strong relation to power-to-weight and free-energy performance across probable wind distribution.
For small cylinders the motor takes more power than the generated power, as indicated in a publication. That would mean that as the balloons scales up, as the motor takes relatively less power.
Concerning Omnidea please see the AWEC2015 presentation on
There are the basic scaling laws of larger motor mass and poorer motor cooling, and also my AWE scaling law that most-probable true wind velocity distribution remains constant, while dimensionless velocity need of larger AWES grows beyond most-probable velocities.
I pleaded with the Portuguese to drop Magnus LTA, years ago, at a conference dinner. Like Altaeros, the helium-dependence down-select took its predictable toll. Both companies now languish offering communications and surveillance capability in a saturated aerostat market. Energy production is naturally now at the bottom of Omnidea’s current application list.
AWE players must pivot to whatever principles emerge to work best, or exit. The LTA players have exited.
I think lighter than air was never on my radar of useful technology for AWE. I think it goes without saying that Helium could only be transitional crutches and hydrogen is pretty dangerous stuff.
So we should keep that out of the discussion which is wether the magnus effect is viable for AWE
Magnus effect balloons can be inflated at any scale with air, thus comprising end caps or a central large disk as for a rotating kite, that in order to assure some stability. If the balloon is very large the relative consumption of the motor could be lesser. Chances for a viable Magnus air (not helium, not hydrogen, not hot air) balloon are not very high but not zero.
Helium “crutch” was masking the weakness of Magnus just to maintain flight mass aloft in normal low wind. It was also the “launching method”. Another problem is that top aerospace pros are not going to do Magnus R&D. Only novices are attracted, a harsh beginning lesson.
@kitefreak this kind of argumentation with arguments not related to the technology in question fails to convince me. Cal me a novice or fool, I will still turn every rock to make AWE happen
Human factors are always “related to the technology in question”.
You are a bit late to Magnus effect, Such kites have been around over 50 years. Magnus AWE has run through about 10M USD. Even as a toy, Magnus is marginal. This rock has been turned over a lot.
No AWE venture has turned over as many different rocks as KiteLab/kPower circle. This is a race, not against each other, but against CO2 rise. At some point you must decide what your focus will be; which AWE principles will do the job, or just enjoy turning back over KiteLab/kPower’s over-turned rocks.
Don’t overlook the many other rocks you have not gotten to. Its Ok to depend on others to have turned some of them. You won’t be turning over the M600 rock, for example. Don’t you have too much already on your hands to perfect KiteMill’s software?
You could buy up Magenn’s hardware cheap, and carry on. As long as anyone believes in Magnus, there is a need to prove it works, or not.
Last I knew, Magenn operated on the Savonius principle, not Magnus.
Making the least-effective type of wind turbine more expensive.
Well, it WAS the least effective until daveS started trying to explore wind energy.
“Turning over every rock” - sure guys.
The “monkey at the typewriter” approach.
As long as the clueless pursue AWE, it will remain a perpetually-open field.
Look at this guy claiming, once again, to be the “top researcher” in AWE.
“No AWE venture has turned over as many different rocks as KiteLab/kPower circle.”
My idea for their slogan: “Exploring exclusively things that don’t work very well.”
or how about “relentless poorly-executed exploration of bad ideas”? Or how about “No power in 12 years and counting”? Maybe “no power meters were disturbed during the filming of this project”?
In 12 years of “No AWE venture has turned over as many different rocks as KiteLab/kPower circle.”, a supposed 5 Watts, 12 years ago, was his max output.
“Turning over every rock”
“a buried concrete block “is really” “a wing”” (JoeF?)
Sure guys! Underground wind energy!
Try looking up instead of down.
The Savonius Rotor develops Magnus Effect, as Wikipedia notes, “the (Savonius) rotor makes the Magnus effect available”. The ST driveshaft also develops Magnus Effect to the extent it can develop angular velocity. Looping kites and any skewed turbine develops Magnus. Its a definite higher-order factor somewhere in most architectures.
As for kite anchor theory and practice, a kite anchor is kite-like, as the mirrored force system. Neglecting anchor engineering-science is to neglect half of the opposed forces. A buried cinder-block is a sort of box-kite to a kite expert. It will hold best bridled appropriately.
Doug seemingly has no idea what has been learned from actually trying AWES ideas known to be marginal, like the LadderMill or Reeling for examples. As Eliot put it-
“We shall not cease from exploration
And the end of all our exploring
Will be to arrive where we started
And know the place for the first time."
The road home led back to the Power Kite.
This is what Im talking about. Magenn’s low AR blimp with a savonius windmill integrated into it does not seem like a best effort design to utilize the magnus effect. Rather it seems like fumbling in the dark.
Bringing this stuff into the discussion adds little value. I tank @PierreB for his honest straightforward reply that he does not believe it will work. I gather the rest of you feel the same. I have little experience with magnus effect. Discussing wether something is viable is a long way from spending real time implementing it… I still think there might be some very good magnus based designs waiting to be built.
(disclaimer totally nonrelated to any Kitemill ongoing work)
Same goes for Omnidea’s high-AR hardware; should be available. All programs pile up prototypes that should be available to loan or sell cheap to sympathetic parties.
High AR has its own trade-off. A buckle is seen forming in Omnidea’s cover-photo WECS. Its presumed they have buckled completely in testing, the central span force is very great in high wind.
The Savonius will beat a smoother Magnus rotor in many conditions, because it bites deeper into the flow. The buckets are dynamically similar to the fuzz on a tennis ball.
Unlike Pierre, I am sure these ideas “work”, under Wubbo’s Principle that a gifted designer can make any kind of AWES they want to work, never mind ruthless market share. Its again the question of what can beat a Power Kite, as the baseline TRL9 COTS WECS in AWE.
I have flown Magnus Effect kites of every kind, both commercial and DIY, since childhood. All “cyclo-kites”, “looping arches”, “tumblewings”, etc. involve Magnus forces, but without the solid-bluff cylinder form. The Best Ever such kite is the Prism FlipKite. Proof of Magnus Effect is that these wings only fly up when rotating in the correct direction.
Adding the open flow Telsa Turbine to the list of variants. Someone should test the Tesla (fun).
Chances for a viable utility-scale electricity generation AWES are not very high but not zero.
Among AWES, chances for crosswind power kite or for lift Magnus air balloon are equivalent.
You think “viable utility-scale electricity generation AWES” is improbable, and that power-kite and Magnus balloon chances happen to be “equivalent”.
How did you calculate these probabilities?