After the posts of Joe and others, I have been inspired to re-draw the kite, as well as the "dual
H-Darrieus" assembly, re-scan it and send it to you here. So, I've placed all of the pertinent
information that I've found, into this one email.
It’s a more
practical design than the last posted drawing, because it utilizes an H-Darrieus
rotor unit with only two blades. Here is some background information on it:
Instead of needing an
elaborate tower to mount it all on, now it's held aloft by a hexagonal lifter
To assemble this very
stable kite, and then send it aloft to only 100-200 feet, would probably
take as much effort as setting up the family tent! Then, an abundance of
electricity can be made.
By changing the design
of the contra-spinning "dual H-Darrieus" rotors to have only two blades per unit
instead of four, it becomes simpler to assemble, and actually, as I have just discovered, more efficient!
What this wind energy engineer, Doug Selsam,http://www.superturbine.info/, has recently written about, makes a
lot of sense. Even though he speaks of propeller blades, I believe that
it can also be translated over to H-Darrieus blades as well. Basically, adding more blades than the original two, only leads to more drag:
“I had the
veterans telling me how dumb I was to suggest more than 3 blades, per rotor
etc., just like beginners do today. I had to listen to the
veterans. I remember the day I dropped from 3 blades to 2 per rotor and
saw my power increase a LOT. Who knew? I slowly found that the
veterans knew a lot that I had no clue of, or just didn't want to
believe. One cannot adequately describe the functioning of a high-speed
rotor in its power band - it has to be experienced to be believed. (wow!)”
This company, Carbon Concepts, who appear to have a
superior design to all other 'Darrieus'-style wind power generators. They do use four blades, but that can easily be
edited back to the original 2-bladed system, from the 1921 patent. They also manufacture their own designed electricity generator. http://www.carbonconcepts.co.uk/
They also are set up to fabricate any shape and contour of a blade that one may
require. I was studying their present carbon fiber blade design, and it
came to mind that the Ultralight trike wing blade shape, that I've come across, may even turn out to be even more efficient. This wing is shaped
in such a way as to most likely increase the leading-edge pull, or lift. (see attachment section^)
even experiment with attaching those"bumps” on the leading edge of the bladewings. Why not? It may just turn out to be all that marine scientist, Frank Fish,
says that it is. If the Humpback whales are doing it, it must be
good, eh? There has to be a particular reason
why these tubercles exist on the leading edge of their pectoral fins. And, I believe that he has discovered why.
They migrate over 5100 miles. These boney
tubercles (that’s right, they are part of the bone structure), comb
water, to make it more fluidic, and less chaotic, as it flows over the
fin. This means that more of an organized slipstream is
created. So too, one might as well place
this “Whalepower” technology on the leading edge of each carbon fiber, V-wing shaped blade. And then receive 20% improvements, according to
the tests they’ve done.
Here is a review made
of Carbon Concepts present-day carbon-fiber blade unit:
"Carbon Concepts, UK based designers of lightweight
composite structures, have developed a near silent vertical axis turbine for
domestic and industrial use.
company have developed carbon fibre technology for a variety of industries and
applications, and applied their experiences with aerodynamics and composite
construction to create an innovative vertical axis turbine which claims to
offer an almost silent operation, even at high speed and load.
The vertical axis machines are generically quieter than
traditional wind turbines, with the novel design of the blade tips rendering
the turbine virtually silent even at the highest speeds. The company do credit
outside assistance, with much of the aerodynamic technology being built on the
electrical generator and aerodynamic expertise from the University of Durham.
Most of the functionality of the turbine is
based around the use of carbon fibre, a material which has added fatigue
resistance, with many other vertical turbines having failed through fatigue in
similar aluminium structures, according to the company.
Testing has confirmed that, even at high
speed and load, the rotor is effectively silent, and attempts to measure the
noise of the rotor showed that perceived noise was dominated by the wind and
The turbine also has a carbon spar made
with glass fibre skins, which is required to keep the fatigue levels below the
endurance limit, providing a virtually infinite life.”
As powerfully-efficient as Doug
Selsam’s multi-rotor system is,
http://www.superturbine.info/, one needs to also consider having a multi-propeller noise factor, which would
be much greater than that of an a multi-unit H-Darrieus system.
Granted, it may not even be close to
producing the same amount of power-output of this multi-propeller system, yet
the trade-off would be its quietness
and portability. Four detachable Carbon fiber V-shaped bladewings, and two rotating hubs, with an electricity
generator in-between, with a slipring
assembly below it.
The other advantage is that these
“contra-spinning”, H-Darrieus assemblies
can be vertically-stacked in numbers, while hanging beneath the kite string pulley. The constant tug from the spring-loaded
spool reel, is fastened below to the ground. This spool may be located about 100 feet away from
where the trailer-mounted kite tether, hand-crank
spool is located.
The multi-propeller system has props spread out on a relatively horizontal, spinning axle. So in that regard, it needs an elaborate
“yawing” rudder fin to stay pointed into the right wind direction. The simpler, H-Darrieus assemblies will continue to spin, no matter what direction the wind is coming from.
I would also venture to say that,
having vertical-spinning, carbon-fiber blades would be more benign to flying
creatures. As these units get larger,
the chaos vortex turbulences also have to be accounted for. There is already trouble with bats’ lungs
exploding, from flying in the downwind vicinity of a wind farm.
Multiple spinning blades mean a
smaller, more concentrated, trailing vortex street. http://en.wikipedia.org/wiki/Kármán_vortex_street
That means a smaller, more intense area of low
pressure turbulence, is created. To
maximise its efficiency and capture the “fresh wind”, these many spinning blades
are tilted, upon its one long spinning axle.
So, the area of downstream chaos vortex turbulence is magnified upon that
one horizontal axis.
Stacked H-Darrieus, contra-spinning
units, would tend to spread its downstream chaos vortex turbulence along a
vertical axis. This means less of a concentrated, low pressure zone in one area.
This is better for the bats, and preventing the barotrauma from happening.
Is it really about making more
wattage than the next guy’s design, or is it more about efficiently utilizing the amount of
power that is being created? That is, highly-efficient
appliances, which would be
used on a daily basis (i.e. refrigerator, lighting, computer, water
electric vehicle). This upgrade to appliances that use
micro-power, could offset a lower wattage output of a not-as-powerful,
more benign, wind energy harvesting system. ~Darin
p.s. There are also some .doc and .pdf attachments to look at.
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