| T O P I C R E V I E W |
| CWAVE |
Posted - 07/05/2008 : 18:36:18
I'm shopping for blades for my Ametek 99 and came across this in my hunting.
http://cgi.ebay.ca/Wind-turbine-generator-blade-propeller-6-rotor-59_W0QQitemZ110248005951
Thinking of going with a 6 blade configuration to maximize my capturing of the wind energy.
Do you think these would work well on my Ametek 99?
Thanks for your comments.
Thomas |
| 6 L A T E S T R E P L I E S (Newest First) |
| gholt |
Posted - 16/05/2008 : 05:57:41
It's my understanding he'll sell them to you in bulk for about $7 per blade. Compare that to the asking price for 3 or 6 blades ... if that's telling.
G. |
| Capt Slog |
Posted - 08/05/2008 : 12:39:08
They look very nice, but I would like to see better photographs than those given there.
1500 rpm, hmmmm, pretty damn quick.
@ windymiller, 1500rpm is 263 mph at the tip. If the TSR was 10, then this would be in a windspeed of 26.35 mph, but I got the feeling reading the blurb that the 1500rpm is the max they have achieved; they JUST break that barrier.
If that was around the max rpm, it would come out to a TSR of around 7 in a windspeed of 37mph.
If the tip speed at 70mph really was 700mph, this would equate to 3990 rpm, which truly is frightening.
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| windymiller |
Posted - 08/05/2008 : 07:48:14
Hi adding to the comments that Fungus highlighted....
Does anybody know the tip speed ratio for this design of blade".
Im assuming the 1500 rpm figure was acheived vertually unloaded.
Loading changes everything in my mind.....also i think if the TPS ratio is close to 10 ,then speeds in excess of 263.5 mph will be acheived at rotor tip
eg.....40mph wind x TSR (10)= 400 mph.
30mph wind x TSR (10)= 300 mph
70mph wind x TSR (10)= 700 mph
These speeds are bonkers....facinating to watch at a distance i expect.
Cheers WM
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| speo |
Posted - 08/05/2008 : 06:45:52
Thomas,
The power the rotor can generate at certain RPM must match with the power your Ametek can generate at that RPM. You must design the blades to match the Ametek 99 motor.
The starting point in this calculation is the open voltage at various RPM's and the winding resistance of your motor. Use P=V*I and I=V/R to calculate the power your Ametek can generate. After that, use a blade calculator (google for it, or use my favorite one posted by Hugh Pigot here: http://www.scoraigwind.com/liselotte/index.htm)
I would dare to say that 3 blades wood carved blades is the best option.
Speo
www.windpulse.com |
| windymiller |
Posted - 07/05/2008 : 21:05:25
Hi cwave.
I like you was drawn into nearly buying some a couple of months ago....but changed my mind.
I think they look good and modern ,but i dont think they deliver the goods expected of them.
This is a gut feeling and not a fact im expressing on this thread.(calm down everybody )
Id need a lot of convincing before i turned round and bought any.
As you have probably guessed ive always got concerns about rotational speed and safety as well.
My feeling also about reaching high speeds consistently is questionable......it largely depends on the type of generator its mounted on.
All swings and roundabouts to make a good genny set up i think.
Fungus......i think i know your answer.....
Cheers WM
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| fungus |
Posted - 07/05/2008 : 19:54:15
http://math.ucr.edu/home/baez/crackpot.html
-5 to start ..
... 1 point for every statement that is widely agreed on to be false 3(do not bend, work well with ametek's, require no maintenance).. - 2
3 points for every statement that is logically inconsistent. 1(very fast *and* super high torque????)- 1
5 points for each word in all capital letters (except for those with defective keyboards) - I count 26? .. - 131
10 points for beginning the description of your theory by saying how long you have been working on it. (10 more for emphasizing that you worked on your own.) - I guess the end sentence .. - 141
20 points for talking about how great your theory is, but never actually explaining it. I guess so .. *161*
I guess my point is, when someone starts shouting in capital letters and using loads of !!!!!'s .. doubt what they say.
:D
Also, at 1500rpm they'd be going at about 263.5mph .. I dont wanna be near them .. and since they're so flexible there is a real danger of them hitting the tower and shattering, as they bend back they make a lot of noise. |
