Homebrewed Electricity > Wind
Tip speed ratio of GOE 222 blades
DaveP68:
Have a set of GOE 222 blades that I purchase recently and plan to use them on a new wind turbine build.
Can anyone on here let me know what the expected TSR is for 3x GOE 222 blades?
As I'm new here can't post any photos of them as yet.
XeonPony:
what is the length of them? I plan on making a set of 4 footers from 2*6 and a set of Hugh Piggott style blade based off his book. on a F&P smart drive motor so would be very interested in the responses to your thread.
SparWeb:
Hi again.
It's been a while since I crunched the numbers on TSR.
IIRC, the TSR on any wind turbine when it's operating is variable, but the pitch of the blades should be set to an optimum where you want the peak efficiency to happen (light wind, strong wind, something in the middle...)
Also, TSR can be matched up directly with the angle of attack of the blade, and the AoA is the angle made by the incoming wind and the air flow as the blade turns. Get the AoA to match the TSR angle and you have hit the optimum.
One thing to watch out for on a GOE 222 is that it has a lot of camber. Setting the AoA by the leading edge/trailing edge angle is not zero lift. The GOE has neutral lift at an angle well below that - several degrees. Yes: here it is
http://www.airfoildb.com/airfoils/962
-8.5 degrees
So in a way that makes it easier for you: Mounting it "flat" to the oncoming wind you already have an incidence angle of about 8 or 9 degrees, which will translates into a TSR of.... maybe 5?
See if my guess is right on Alton Moore's page: http://www.alton-moore.net/wind_calculations.html
DaveP68:
--- Quote from: XeonPony on October 27, 2017, 11:27:23 AM ---what is the length of them? I plan on making a set of 4 footers from 2*6 and a set of Hugh Piggott style blade based off his book. on a F&P smart drive motor so would be very interested in the responses to your thread.
--- End quote ---
My GOE 222 blades are 1.3 m (4'3) long so hub radius is going to be 0.2 m total diameter 3 m (9'10).
Here's a photo for scale showing 3x 1 m blades mounted on a hub with a single GOE 222 blade along side.
I recommend using the 36 pole copper stator with the stronger black 48 magnet rotor cap. There are 5 different versions of F&P stators out there. What do you have access too?
David
DaveP68:
--- Quote from: SparWeb on October 27, 2017, 02:20:13 PM ---Hi again.
It's been a while since I crunched the numbers on TSR.
IIRC, the TSR on any wind turbine when it's operating is variable, but the pitch of the blades should be set to an optimum where you want the peak efficiency to happen (light wind, strong wind, something in the middle...)
Also, TSR can be matched up directly with the angle of attack of the blade, and the AoA is the angle made by the incoming wind and the air flow as the blade turns. Get the AoA to match the TSR angle and you have hit the optimum.
One thing to watch out for on a GOE 222 is that it has a lot of camber. Setting the AoA by the leading edge/trailing edge angle is not zero lift. The GOE has neutral lift at an angle well below that - several degrees. Yes: here it is
http://www.airfoildb.com/airfoils/962
-8.5 degrees
So in a way that makes it easier for you: Mounting it "flat" to the oncoming wind you already have an incidence angle of about 8 or 9 degrees, which will translates into a TSR of.... maybe 5?
See if my guess is right on Alton Moore's page: http://www.alton-moore.net/wind_calculations.html
--- End quote ---
Hi SparWeb
Good stuff and tried out the online calculator very useful to plug some numbers into.
My guess is for 3x GOE 222 blades the TSR should be from 5 to 5.5 as have been able to observe how Fred's (flc1) GOE 222 blades are performing on his 4 blade wind turbine. My calculations are rough as not able to get accurate wind speed readings from Fred vs the operating RPM range. From what I can work out the TSR on his wind turbine is just over 4 (I think 4.25) with 4x GOE 222 blades (his blades are identical to mine).
David
Navigation
[0] Message Index
[#] Next page
Go to full version