hydro to windmill application - turn only in one direction

[developer]

http://www.web7days.com/hydro/W.jpg
the during of the high wind is a cruical factor , If I have read the wind
turbine right, 12km/hr. HK is very windy in winter time.

Q. I do not know how to make the windmill turn only in one direction.


the wheels now turn itself into windmill since the water level in stream is
very low. no high volume of water to be tested.

phototype only, I will much better materials, and change a few screws, it is
all irons. it is much stronger than aluminium.


the boards are picked up from street only. Will make coils in china and see
if I can find magnets, I have the Black magnets that I have brought from HK
side. That is not the type required.

 

[Rich Grise]

On Tuesday 05 October 2004 02:47 pm, developer did deign to grace us with
the following:

http://www.web7days.com/hydro/W.jpg
the during of the high wind is a cruical factor , If I have read the wind
turbine right, 12km/hr. HK is very windy in winter time.

Q. I do not know how to make the windmill turn only in one direction.

Mount it at the top of a tower, on a pivot, with a rudder. Let the wind

turn it.

I've also seen them with a little fan, like the tail rotor of a chopper,
which, when the wind was sideways to the main axis at all, the little
fan would turn, and it was mechanically linked to a rotator gear. Of
course, when it was lined up, the little rotor is sideways to the wind,
so it's self-aligning. Watch your polarity here!

Good Luck!
Rich

 

[Rich Grise]

On Tuesday 05 October 2004 02:47 pm, developer did deign to grace us with
the following:

http://www.web7days.com/hydro/W.jpg
the during of the high wind is a cruical factor , If I have read the wind
turbine right, 12km/hr. HK is very windy in winter time.

Q. I do not know how to make the windmill turn only in one direction.


the wheels now turn itself into windmill since the water level in stream
is very low. no high volume of water to be tested.

phototype only, I will much better materials, and change a few screws, it
is all irons. it is much stronger than aluminium.

Use aluminum for the blades (if you can get it) - you shouldn't need much

strength there, and possibly even for the blade struts - they only need to
be strong at the hub.

the boards are picked up from street only. Will make coils in china and
see if I can find magnets, I have the Black magnets that I have brought
from HK side. That is not the type required.

Geez, it sounds like you might find a generator in the street! Wander
around the back alleys of an industrial area - you never know what you
might find!

Cheers!
Rich

 

[ChrisGibboGibson]

bigcat@meeow.co.uk (N. Thornton) wrote:

"developer" <developer@nosina.com> wrote in message
news:<cjv4ou$7hu1@imsp212.netvigator.com>...
http://www.web7days.com/hydro/W.jpg
the during of the high wind is a cruical factor , If I have read the wind
turbine right, 12km/hr. HK is very windy in winter time.

Q. I do not know how to make the windmill turn only in one direction.

1 tail fin.
2 let it turn both ways, no prob.

twisted blades with more pitch in centre, less at outwer edge, will
give better efficinecy.

Slip rings allow the head to move either way.

Do an internet search for "wind turbine" and "diy". Google returned 850 english
hits.

Gibbo

 

[developer]

"N. Thornton" <bigcat@meeow.co.uk> Đ´ČëÓĘźţ
news:a7076635.0410061131.16b541a8@posting.google.com...

"developer" <developer@nosina.com> wrote in message
news:<cjv4ou$7hu1@imsp212.netvigator.com>...
http://www.web7days.com/hydro/W.jpg
the during of the high wind is a cruical factor , If I have read the
wind
turbine right, 12km/hr. HK is very windy in winter time.

Q. I do not know how to make the windmill turn only in one direction.

1 tail fin.
2 let it turn both ways, no prob.

twisted blades with more pitch in centre, less at outwer edge, will
give better efficinecy.

NT

the spinning motions

http://www.web7days.com/hydro/implementation/9.MOV

http://www.web7days.com/hydro/implementation/19.MOV
http://www.web7days.com/hydro/implementation/7.MOV


developer

 

[Dan Major]

bigcat@meeow.co.uk (N. Thornton) wrote in
news:a7076635.0410080326.10bb720@posting.google.com:

To make something maximally efficient like an aeroplane prop would
take some carving, and I dont think it would be easy. Beyond me
anyway! At least the type of blades on there now run at lower speed,
which, considering the way theyre put together, might turn out to be a
blessing.

NT

What about a vertical windmill - one of the "eggbeater" styles. The shape

of the blades is *much* less critical, plus it is direction insensitive.


--
Sooner dot boomer at gbronline dot com

 

[Angelo Campanella]

N. Thornton wrote:

To make something maximally efficient like an aeroplane prop would
take some carving, and I dont think it would be easy. Beyond me
anyway! At least the type of blades on there now run at lower speed,
which, considering the way theyre put together, might turn out to be a
blessing.

Generations ago it was clear that the most efficient propeller is one
with the largest diameter with the fewest blades. This is clear today in
the light plane industry where the most efficient designs have two
bladed props. (See Rutan's round the world aircraft design; most of the
time, their rear engine was operating; it had a 2-bladed prop.) I own
and fly a 1979 Mooney 201 with a 200HP engine, and it still has a 2-
bladed propeller. Years ago, propeller manufacturers decided that a
3-bladed propeller will "look nicer, be quieter and produce the same
thrust". well, I stood by and awaited the field data that would support
his contention. One of the propeller manufacturers rented my aircraft
for a few weeks to determine true flight performance. Afterwards, I
asked; the answer was that the takeoff and climb were better, but that
the cruise speed was a few knots less. Needless to say, I turned down
their successive 'deal' for me to buy one at a discount. (I was
interested in MPG and not 'pizzazz'.)

The only reason to switch to 3-, 4-, or 5- bladed propellers is to
accommodate aircraft designs where abundant excess power is available,
where noise is an issue (blade tips nearing the speed of sound), takeoff
or climb and top (military aircraft) speed, propeller ground clearance,
or load carrying capability must be maximized with little consideration
of energy efficiency.

In my youth, I built and flew some rubber band powered endurance model
airplanes. "Endurance" means that one wants the longest -time flight
possible with a single charge of torque in the form of a manually
twisted rubber band. All the best endurance designs employed a large
diameter ONE bladed propeller (with a counterweight to avoid vibration).
These designs were clearly optimized through real flight and competition
experience to produce the longest-time flights with a single (manual)
rubber band windup store of rotational energy.

The present 'California'(?) windmill power generator designs employ a
huge diameter two bladed propeller, which I fully expect to be the norm
for at least all of the 21st century. A one-bladed design is also
reasonable where the maximum energy extraction efficiency is the goal,
especially since greater wind speeds are available at greater heights.

Angelo Campanella

 

[Ken Smith]

In article <41661433.30DF555F@Hovnanian.com>,
Paul Hovnanian P.E. <Paul@Hovnanian.com> wrote:
[...]

The OP should do a search on the optimum aerodynamics for turbine
efficiency. It ssems to me that the blades on his windmill are too wide
and too close together, blocking too much of the wind as it passes
through.

IIRC, many broad blades provide better torque, but lose efficiency at
higher speeds and as a result, do not generate the maximum possible
power. The broad blade designs were OK for well pumps, where gearing
down high RPMs was uneconomical.

Wide blades create more torque when the blades are stalled. Their losses
rise at higher wind speeds. This is something you may want to have
happen. At some wind speed, the generator is maxed out. To protect it
from overspeed, you need to apply a break or spoil out the turbine.

The power from wind goes as the cube of wind speed. This makes getting
enough power from a 15MPH wind and surviving a 60MPH wind a bit of a
design problem.

--
--
kensmith@rahul.net forging knowledge

 

[Paul Hovnanian P.E.]

"N. Thornton" wrote:

Angelo Campanella <a.campanella@att.net> wrote in message news:<Xiw9d.509658$OB3.102200@bgtnsc05-news.ops.worldnet.att.net>...

Generations ago it was clear that the most efficient propeller is one
with the largest diameter with the fewest blades. This is clear today in

A most interesting story. Will we ever see 1 bladed windmills?

For single phase, yes. Three blades are for three phase, right? ;-)

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
"Si hoc legere scis nimium eruditionis habes."
(If you can read this, you're overeducated.)

 

[Rich Grise]

On Friday 08 October 2004 03:02 pm, Paul Hovnanian P.E. did deign to grace
us with the following:

"N. Thornton" wrote:

"Paul Hovnanian P.E." <Paul@Hovnanian.com> wrote in message
news:<41661433.30DF555F@Hovnanian.com>...
"N. Thornton" wrote:

twisted blades with more pitch in centre, less at outwer edge, will
give better efficinecy.

The OP should do a search on the optimum aerodynamics for turbine
efficiency. It ssems to me that the blades on his windmill are too wide
and too close together, blocking too much of the wind as it passes
through.

IIRC, many broad blades provide better torque, but lose efficiency at
higher speeds and as a result, do not generate the maximum possible
power. The broad blade designs were OK for well pumps, where gearing
down high RPMs was uneconomical.

To make something maximally efficient like an aeroplane prop would
take some carving, and I dont think it would be easy. Beyond me
anyway! At least the type of blades on there now run at lower speed,
which, considering the way theyre put together, might turn out to be a
blessing.

I was thinking more along the lines of having the OP remove every other
blade (or more) and open up the path for the airflow. I think the gain
from this improvement will be greater than that of an improved airfoil.

I've lost track of the original picture, but it seems his blades were

pretty flat - they should be twisted, like propeller blades - i.e., steeper
pitch closer to the center.

Cheers!
Rich

 

[Paul Hovnanian P.E.]

ChrisGibboGibson wrote:

[snip]

For reasons you don't need to know I live "off grid"

Thanks to the maintenance practices of my local power company, so do I
on occasion. :Ź}

I use a comercial wind turbine (an Air-X using genuine hydrofoil style blades)
that has had every mod you could possibly think of.

I can certainly confirm that adding 3 extra identical blades to a 3 bladed prop
*does* result in a decrease in performance.

That's as much as I know about it.

The simple explanation (I think) is to picture the helical pattern that
each blade travels along relative to the air mass passing through it.
Each blade creates a turbulent wake in such a pattern. If the RPM is too
high compared to wind speed and the next blade follows too close, it
winds up traveling in the wake of the previous blade.

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
Power corrupts. And atomic power corrupts atomically.