40% more efficient? Does anybody have any info on this?
Thx
Rob
http://peswiki.com/index.php/Directory:Home_Energy_Energy_Ball
Lot's of blade-type VAWT's use at least some of the venturi principle. If you have Air-flow or fluid dynamics software, you could evaluate each of the many types of these on the market, or maybe your own design. Of course, not evryone has that type of computer & software.
Here's another one making good use of the Venturi principle:
http://peswiki.com/index.php/Directory:FloDesign_Wind_Turbine Rural McG
http://www.home-energy.com/engels/ebv100technical.htm
These numbers show up:
But, it won't be my money being spent on it and it won't be mounted to my roof.
Ron Adventure is just bad planning." -- Roald Amundsen
Maybe next summer I will try again. It did freak me out that it didn't at least work some though. I even tried flipping the blades backwards-- but no-go.
But I am not too smart, so maybe they figured out something that works!!!
Thanks for sharing the links. Maybe I can find the answer(s) as to why mine did not work.
But you need the blades to be an airfoil shape, with a curved leading edge and a pointed trailing edge. (The wind has to attach to the blade from a number of angles on the curved leading edge and exit at right angles to the axis from the pointed trailing edge.)
And it probably won't be self-starting with just the blades. So you'll have to spin it up to get it going. Either by running the genny as a motor or hanging on an extra starter motor, or by attaching a smaller, drag-type self-starting mill, scaled down to get the same RPM despite the drastically different tip speed in normal operation. (Say a Savonius. Figure about an 8-to-1 ratio of diameters, since the Savonius will be running at a TSR of about .8 and the Darrieus will want something in the 6-7 range.)[ Parent ]
I'm not a big fan of high speed VAWT's overall because of the constant maintenance. Basically a failure waiting to happen unless thier watched and inspected continuously.
Your definately thinking out of the box.. keep it up you'll find success in the strangest places. .
Have Fun! Windstuff Ed[ Parent ]
It was perfectly balanced and if you slightly pushed anywhere on any of the blades while stopped, it would propel nice in the same direction. In a good wind (say 16-20mph) , I would spin it fast with my hand, but it would slow down and only turn slowly in the big wind. It was just a quick, crude proto, but it freaked me out that it didn't do better than it did. Maybe wider blades that go more vertical??
In my dream the HawtVawt ran like a jet. But in reality it was a nightmare!!
But that 'Ball mill' looks interesting to me, but on a bigger scale. Thanks for the link Rob. Always trying new things.
What got me interested in something like that was a concept mill I had seen a couple years ago from a German designer-- it was called the "Windus".
http://www.treehugger.com/files/2005/09/der_windwandler.php
They evidently were not able to start the company. There website no longer works. http://www.windwandler.de/
Or www.windwandler.com It was difficult for me to even find a picture of it. The high output they claimed was, in my opinion, outrageously over stated. (3.8K If I recall) Who knows if the thing even worked at all.
But that "Ball mill" is certainly being made from a company at least,, even though I certainly do not believe there stated output either. I'm sure it does some decent power though. But As we can see there is no aerofoil shape to the blades for lift, which means more drag than a Hawt. The blades look somewhat flimsy. But it still looks very interesting to me though.
I highly doubt anyone could ever beat the Hawt in a proper clean,high location, but what I dream of making is something that looks good on a roof top and that people (neihbors) won't even know what it is. (even if it can only do HALF the power of a similar size Hawt for a small power system)
Also it has to be more quiet than a small hawt so a person can put a few of them on one's roof since the roof is usually not a good place to put a mill. [ Parent ]
