Author Topic: nose cone (Read 11142 times)

Beanbread · « **on:** October 14, 2011, 03:59:05 PM »

Anyone know if a nose cone helps in anyway on a small wind generator.I have a 125 watt with three 19 inch blades.I live in an area with very little wind and am trying to pick up all I can when I do get any.

Rover · « **Reply #1 on:** October 14, 2011, 04:10:34 PM »

Hi Beanbread,

Although there are some places that you will find that swear you need a nose cone, in my experience with small turbines it does not make any difference. I never use one.

Some might argue on the aesthetics , making it look better, always thought they looked fine on there own.

With a small turbine like yours I don't expect any improvement in performance at all. Sorry, but there are very few ways (if any) to improve the performance of a turbine that small. (There are however, a lot of ways you can try, and you will be encouraged to do so by many EBay vendors, don't buy into it)

You may be able to improve performance by raising the tower height though.

Rover

Beanbread · « **Reply #2 on:** October 14, 2011, 04:43:17 PM »

Thanks Rover

Yes raising the tower would help but I'd probally have to go 60 foot I'm at 20 now and thats going to have to do.

I've built several blades from pvc and think the one's I have now are best.They are cut like most you find on the web but cut at 10 degrees off the center line toward the leading edge.they seem to get turning quicker.

Rover · « **Reply #3 on:** October 14, 2011, 04:49:55 PM »

Part of the fun is experimenting, and it sounds like you are in to the fun part. Don't get discouraged, you may come with something radical that changes everything.

Now the down part, more than likely the PVC blades will not spin fast enough for you mill, usually something that small needs some really high velocity blades and a lot of wind.

But try it anyway, as a lot of us did when counseled against it ... .

Rover.. .(guilty of doing things he was told wouldn't work)

ghurd · « **Reply #4 on:** October 14, 2011, 09:25:35 PM »

There was a small maker/seller of smaller wind turbine parts who did a fairly decent test of nose cones.
They said the output actually went down very slightly, acording to there meters.
Im my opinion, it is one of those things that wouldn't help... or hurt... most systems.

G-
(guilty of REPEATEDLY doing things he was told wouldn't work)

Beanbread · « **Reply #5 on:** October 14, 2011, 09:37:25 PM »

I guess I'll leave it off then, but I'm thinking of adding three more blades...think it would be worth it?

Dave B · « **Reply #6 on:** October 16, 2011, 06:23:39 PM »

If you don't want to build a nose cone or to figure out a prefab way of doing it then it's easy to convince yourself not to have one. If you need even more convincing then find reports that say it's less efficient to have one. We don't see many on these home made machines but if you know you really want one then make one. You already know you will be glad you did. Dave B.

Rover · « **Reply #7 on:** October 16, 2011, 06:53:17 PM »

Hi Dave,

Do you have any experince with nose cone vs non-nose cone? I'd like to hear you experience if you found a difference.. I didn't . But honestly that doesn't mean anything... even opinion is fine..

Rover

Dave B · « **Reply #8 on:** October 16, 2011, 08:53:10 PM »

I never built one without a nose cone. The difference I see is looking finished or not. Sure it's work but to me well worth it. More efficient with or without it ? Don't know. Dave B.

Quote from: Rover on October 16, 2011, 06:53:17 PM

Hi Dave,

Do you have any experince with nose cone vs non-nose cone? I'd like to hear you experience if you found a difference.. I didn't . But honestly that doesn't mean anything... even opinion is fine..

Rover

kitestrings · « **Reply #9 on:** October 17, 2011, 05:11:19 PM »

Nosing right in here -

Frankly, any turbine without a nose cone is out half-dressed IMHO. I'm only half serious of course, but I thought it'd rile someone up about it.

There have been folks here that have suggested that they create more drag than they improve on. I 'm not convinced it is proven - certainly not by the one 'commercial' source noted. It would seem logical if they are real large.

Some folks have also suggested that the airflow increases over and around the cone, and can enhance the redirect air to the portion of blade with the sharpest angle/most drop, therby improving things at the root section(s). I'm not convinced that is proven either, though it sounds more plausible to me.

I have found one advantage to be weather protection. If the cone covers the blade hardware at all it will have less corrosion. If you have any sort of pitch control like what Frans has posted recently, I'd think they would make a great deal of sense.

Otherwise, they just plain look happier to me with a cone. It seems odd that you never see a plane without one. I took my son on a glider ride before he got married. I noticed that the nose of it was not flat.

Regards,
~kitestrings

ghurd · « **Reply #10 on:** October 17, 2011, 07:42:58 PM »

Being the devil's advocate...

Quote from: kitestrings on October 17, 2011, 05:11:19 PM

There have been folks here that have suggested that they create more drag than they improve on. I 'm not convinced it is proven - certainly not by the one 'commercial' source noted. It would seem logical if they are real large.

I could argue the opposite. Messing around with a large percentage of the air flow is an unknown, unless very detailed testing was done.

Quote from: kitestrings on October 17, 2011, 05:11:19 PM

Some folks have also suggested that the airflow increases over and around the cone, and can enhance the redirect air to the portion of blade with the sharpest angle/most drop, therby improving things at the root section(s). I'm not convinced that is proven either, though it sounds more plausible to me.

Plausible, maybe.
But the area around the cone is by far the least efficient. By far ^ 2!
Example: By the math, how close to perfect is the center 20% of your blades? Not even close? Therefore, if the center 20% of the blade efficiency increases 30%, how much % does that really gain, overall? Nothing worth calculating.

Quote from: kitestrings on October 17, 2011, 05:11:19 PM

I have found one advantage to be weather protection. If the cone covers the blade hardware at all it will have less corrosion. If you have any sort of pitch control like what Frans has posted recently, I'd think they would make a great deal of sense.

I seem to recall more issues of loose hardware. A nose cone could hide it.

Quote from: kitestrings on October 17, 2011, 05:11:19 PM

Otherwise, they just plain look happier to me with a cone.

No argument there!
There were more than a few 'simple' nose cones posted over the years. From toilet or plumbing parts, to roofing parts, to hub caps, to (parts of) holiday decorations.

I do kind of like the rusty nuts and bolts showing so the world knows it is not something I bought at HF.
G-

Dave B · « **Reply #11 on:** October 18, 2011, 03:16:01 AM »

I just have to say again that I believe it is the amount of work involved and or not knowing just how to go about it. Add this to the fact that if you are that close to raising your turbine and you are as anxious as the next person to see the machine fly it simply goes up without one. At that point it sure is easy to convince yourself it doesn't need one or it looks just fine without one. To me the extra work and patience involved with putting that finishing part on the machine is soo worth the effort. Like a few others here in the board I guess I mostly do what I want. Dave B.

richhagen · « **Reply #12 on:** October 18, 2011, 05:12:04 AM »

Beanbread - "I guess I'll leave it off then, but I'm thinking of adding three more blades...think it would be worth it?"

If the three blades were designed for that turbine and are a good match, then adding three blades would not help it, but in fact would hurt it. If they are a mismatch at present then all bets are off. Rich

Beanbread · « **Reply #13 on:** October 18, 2011, 11:41:51 AM »

If the three blades were designed for that turbine and are a good match, then adding three blades would not help it, but in fact would hurt it. If they are a mismatch at present then all bets are off. Rich

This generator came with six 12 inch blades,they never moved in three months.I replaced them with three 19 inch blades and it started spinning the same day.But its never got up to 12 volts as yet.
BTW I did go ahead and put a small nose cap on it yesterday, 3 inchs accross so it can't hurt anything and looks a little better.lol

kevbo · « **Reply #14 on:** October 18, 2011, 11:54:13 AM »

Airplane folks have been calling them spinners since forever. Nosecones are for rockets.

Dave B · « **Reply #15 on:** October 18, 2011, 12:16:46 PM »

It's not an airplane and spinners and whirlygigs are lawn art. TURBINE sounds like a jet fast like a rocket. That's a nose cone on my turbine. (insert smiley) Dave B.

Quote from: kevbo on October 18, 2011, 11:54:13 AM

Airplane folks have been calling them spinners since forever. Nosecones are for rockets.

spitfire · « **Reply #16 on:** October 18, 2011, 02:10:52 PM »

I have not noticed any significant improvement

SpitsFire

SparWeb · « **Reply #17 on:** October 18, 2011, 02:49:17 PM »

Who has the instrumentation accurate enough to detect a difference with or without the spinner/nose-cone?

kitestrings · « **Reply #18 on:** October 18, 2011, 04:58:40 PM »

spitfire,

You've just validated my last point. Look how happy, confident and well adjusted that fine turbuine looks

Regarding hardware - yes, lose spinners/cones can be a nusance, but that can be avoided with good hardware. On some of the older machines with taper-lock bushings they are a big help.

Also, with wood blades, particularly those that have seen there share of age & weather, I've noticed that the blunt, end-grain can be an area that starts to devlop problems earlier (checks, peeling, etc). In turn, I think it may lead to more wicking of moisture and deterioration of finish on the blades. They seem to be in better condition if protected by the cone.

~kitestrings

Steadfast · « **Reply #19 on:** June 06, 2012, 06:30:40 AM »

I was thinking about adding a nose cone to my HBird turbine....
Right now it will have a 10 inch flat wood front hub...
(Sort of like putting a bar stool, seat first, in the air)
a nose cone may not help out put efficiency...
but
Would it help reduce horizontal thrust...

just-doug · « **Reply #20 on:** June 08, 2012, 08:48:42 PM »

Beanbread,i would carve a wood set about 24 inches in diameter, threeblades, about three inches wide,10 to12 degrees pitch.no taper or twist.could probbly get it out of a 1 by 4.let us know how it goes

fabricator · « **Reply #21 on:** June 08, 2012, 10:05:56 PM »

The nose cone would only marginally affect the air stream in the area of the root, which is totally useless as far a power output is concerned, where the nose cone actually is right on the hub it should make nothing other than an esthetic difference.
Also anything more than three blades is a total waste, that WILL cause a power loss, it's been shown over and over, yet, you still see these carpet bagger scammers sellling turbines with 5,6,7 blades. One blade is best but a nightmare to balance, two blades are second best but yawing in turbulent winds can be horrific on a two blade machine.
So we are left with the trade off of three blades, Virtually every utility scale turbine you see has three blades, AND, a nose cone.
They don't build multi million dollar turbines without a LOT of R&D.

XOKE · « **Reply #22 on:** August 15, 2012, 07:37:35 PM »

Hi, in last days I start my first windmill servicing
The blades painting let some moisture get in, so I need to paint it with good quality paint, I buy one with UV protection and Water Proof 10 years guarantee,
A friend gave to me a nose cone that fixes exactly in the root blades,
I believe that don't affect the performance of the wind generator, its more just to dress the Generator.

Xoke

midwoud1 · « **Reply #23 on:** August 16, 2012, 04:53:54 PM »

I dont know if it has an aerodynamic effect , I use it to protect the pitch-control mechanism.
It's made of polyester lightweight no balance problem, works good for 1 year now.

Xoke your spinner looks good what kind of material is it made of ?

- F -

XOKE · « **Reply #24 on:** August 16, 2012, 05:46:36 PM »

Hi,

ItÂ´s made of polyester resin and fiberglass, has 170mm of height and 25mm of diameter.
It was done by a guy that works with all kind of resin and fiberglass, he built wind gen blades any diameter we need, nose cone, boats, car parts, etc.

You have a something cool machine.

Xoke

synovialbasher · « **Reply #25 on:** August 20, 2012, 06:06:34 AM »

A nosecone wouldn't help much in picking up on light winds, because there is so little energy in them! I would still add it for the aestetics, but as for performance it wouldn't make much of a difference. There is 70% more energy to be harnessed in a 12 mph wind than a 10 mph (HomePower magazine, www.homepower.com). It's not worth all the effort to attempt and capture every breeze that blows through. There are other things you can do, though, to increase power production. A 38 inch diameter rotor isn't very big, and for every extra square foot of collector area you end up with 4 times the poewr. I personally just upgraded my 4ft diameter turbine to a 6ft, and I can say from personal experience it changes the entire machine. A taller tower would definetely benefit also. For every 2 feet you raise the tower, that's twice the power (all of this information is from Home Power's magazine). So would a nosecone benefit? Yes. From a physics view it would reduce drag on the front of the rotor and move the air to the blades where it will become more useful. Is it really worth your time? Compared to all the other things you can do, no.

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Author Topic: nose cone (Read 11142 times)