navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: 1kw turbine noise reduction  (Read 4875 times)
Adam
Sr. Member
****
Offline Offline

Posts: 252


« on: July 21, 2006, 08:57:54 PM »

When i installed my 1kw turbine i found it quite noisey but i got quite used to it. However as the turbine wasn't balanced well i decided to lower the turbine and rebalance it.
As i was rebalancing the turbine i thought it would be a good idea sand down the "cut edge" and the tip, the cut edge is part of the blade that is cut at an angle wich runs for about 8-10 inches towards the tip, it appeared to be just cut and unfinished so i sanded it down to a point like the rest of the blade in an attempt to make it more streamline and efficent.
Once i finished balancing i then rearected the turbine i found that it was at least 80/90% quieter.

I hope this helps (if you can understand any of the above) Thanks Adam
Logged
Alternative
Newbie
*
Offline Offline

Posts: 19



WWW
« Reply #1 on: July 28, 2006, 10:52:14 AM »

Your comments are very interesting to me. I have just bought a Navitron 200 watt turbine and want to minimise the noise from it. I wonder if your modifications might be applied to my turbine blades which are parallel sided and have no angle cut like yours appear to have? Maybe someone else has experience of this?
Logged

Alternative Technology and Renewable Energy at Home

http://www.alternativetechnology.info
Ivan
Guest
« Reply #2 on: July 30, 2006, 01:44:11 AM »

Hi Adam,

Useful info - can you attach a picture to show what the modifications look like?

We are currently working on some replacement blades (which will be more expensive) that have twist and taper - which will be classed as 'low noise' blades. The blades are available now in 200W, 500W and 1kW format. However, we still have not produced the hubs, which will not be available until around September time.

ivan
Logged
Adam
Sr. Member
****
Offline Offline

Posts: 252


« Reply #3 on: August 03, 2006, 09:12:01 PM »

If you can see int the picture, the blade on the right with the arrows marked on has been sanded down to a point by myself between the arrows.
The blade on the left is new and untouched and you may be able to see the blunt edge were it appeares to be cut off and not sanded down.
I have had to replace two of the blades as one of the guy ropes had a brief encounter with a tractor and baler, unfortunatley the turbine ended up ontop of the tractor and i have not yet sanded or balanced the blades yet.

adam


* DSC04082.JPG (30.44 KB, 463x411 - viewed 622 times.)
« Last Edit: August 03, 2006, 09:27:00 PM by Adam » Logged
Phil
Guest
« Reply #4 on: August 04, 2006, 09:27:27 AM »

   I have a navitron 300 watt turbine  I   taped all three blades firmly together then carefully using and angle grinder just very slightly sanded off the 2 corners at the very end of the blades (making it almost a semicircle at the end of each blade).

 it had a marked improvement on the noise level,  although  very slightly reduced the effectivness of the turbine in low winds, but as I am on a mountain in south Wales that wasnt a problem !

Logged
pat
Newbie
*
Offline Offline

Posts: 37


« Reply #5 on: August 29, 2006, 08:52:23 PM »

Your blades appear tapered at the end, were these blades specialy made, could this modification be made to the standard blades.
Logged
Adam
Sr. Member
****
Offline Offline

Posts: 252


« Reply #6 on: September 08, 2006, 10:12:35 PM »

Hi pat, these blades came like that (with navitron 1kw turbine).
Logged
perkins
Newbie
*
Offline Offline

Posts: 9


« Reply #7 on: February 13, 2007, 07:17:13 PM »

Hi,

I have just received my 2Kw wind turbine complete with fibreglass blades which already have a radius on the tips. They also have quite large moulding seams along the leading and trailing edges of the blades.

Does anyone know if removing and blending in these seams will reduce the noise of the turbine at all ? It's a lot of work to undetake if there is no real benefit, but worth it if it works.

Could some kind soul give me the benefit of their experience before I dive in - sanding fibreglass isn't my favourite passtime and just the thought of it makes me itch !

Any advice gratefully received.

Cheers
Logged
Ivan
Guest
« Reply #8 on: February 18, 2007, 01:06:16 AM »

I believe the 2kW wind turbines come with a low noise blade as standard - so you do not need to do anything. The 'seams' you mention are very deliberate - this type of blade is made in two pieces and then attached together. Having a wider seam gives more strength to the join, which makes the blades more resilient to spliting. Don't be tempted to remove these !

Ivan
Logged
Bargeman
Guest
« Reply #9 on: February 18, 2007, 10:27:05 AM »

Hello Ivan,

Whilst we're discussing turbine blades, how about the latest in blade design for low wind speeds sites (5.8 m/s average wind speeds), see http://www.sandia.gov/news/resources/releases/2007/blade.html. Do you think the Chinese could be persuaded to take a look ?

We could do with something like these Sweep Twist Adaptive Rotor blades to help eke out power from our pretty paltry wind resource down here in Kent, where 5.8 m/s is not far off the best average wind speed we can expect.

regards
Logged
Ivan
Guest
« Reply #10 on: February 18, 2007, 02:28:39 PM »

I read the article - the key aspect that they are using to increase power is to use very long blades for a given size turbine - that is exactly what the Navitron turbines do for our range of turbines up to 2kW - this gives them great performance advantage over the competition. The novel feature they are using - the blades that sweep back - is apparently to help reduce fatigue from gusts. From the picture, it looks as though they are applying this to a 5-10kW design. The classic American mid-West wind turbine is a multibladed machine that works very well in very light winds, but being based on drag rather than lift, it is a low-efficiency design. Hence their new design will see big improvements in efficiency compared to the standard mid-west wind turbine.

The only way to improve on the power at low wind speeds is to use a traditional design - eg savonius or multi-bladed design or one of the modern variations. These will produce a small amount of power (usually 10-200W) in very light winds, but their performance is lousy at higher wind speeds (ie not much more) and they tend to be very large. From a practical consideration, they require low speed alternators (60-200rpm) which means having many more poles in the alternator - and this is expensive to manufacture. We are looking for a decent savonius derivative to sell, but so far, everything we find is priced rather highly compared to our current wind turbines.


Ivan
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!