h a l f b a k e r yAsk your doctor if the Halfbakery is right for you.
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
A vertical windmill is one that rotates along a vertical axis. The two types are lift and drag. The drag type is exemplified by two cones connected on a vertical axis free to rotate, common on ornamental wind vanes and wind speed indicators. The lift type use the principles of airfoils. They generate
lift when neither perfectly perpendicular nor perfectly parallel to the wind direction.
A lift type windmill suffers fatigue, vibration, and noise due to the lift component alternately pulling and not pulling as the windmill rotates. Various solutions have been tried, such as extending the vanes into a helix shape.
Part of the cause of this fatigue and noise is wind separating from the lift surface at high angles of attack. This is an inevitable phenomenon when you're rotating a wing through 360 degrees. But wind cohesion can be improved. If the stall angle is raised there will be less fatigue as the range of directions the vanes are pulled in is reduced.
Furthermore increasing angle of attack before a stall will increase lift as the airfoil pulls over a wider range of motion.
Golf ball dimples aren't used on aircraft wings because the additional drag makes it not worth it. But for windmill airfoils drag doesn't matter nearly as much.
So the idea is to put golf ball dimples on the surfaces of lift type vertical windmill blades thereby maintaining laminar flow over a wider range of motion.
vertical windmill
https://granitegeek...is-wind-turbine.jpg
[Voice, May 15 2021]
Stall at high angle of attack
https://youtu.be/6UlsArvbTeo?t=68
[Voice, May 15 2021]
Dimples on golf balls maintain laminar flow
https://www.researc...es-on-golf-ball.png
[Voice, May 15 2021]
Please log in.
If you're not logged in,
you can see what this page
looks like, but you will
not be able to add anything.
Destination URL.
E.g., https://www.coffee.com/
Description (displayed with the short name and URL.)
|
| |
Is this a technology for water turbines (as per. category)? |
|
| |
Is this a technology for wind turbines? |
|
| |
Is this a technology for golf balls? |
|
| |
Or is this a secret code? |
|
| |
I think maybe [Voice] was trying to remember the word ‘helicopter’
when writing “horizontal lift windmill”. So, this is a helicopter
covered in the same kind of dimples as a golf ball, presumably for
the same clever aerodynamic reasons. Not a bad idea at all. |
|
| |
Ah, [Voice] has rewritten it since my earlier
annotation... |
|
| |
If you know what direction the helicopter blades or
windmill blades are going to rotate then perhaps a golf
ball hemisphere dimple could be replaced with an oval
tailed dimple to maximize laminar flow. genetic
algorithms
could be used to make the best oval dimple shape. |
|
| |
Also, considering the way helicopter blade rotation speed
causes the perimeter to rotate faster (through more air)
dimples could be adjusted for the length -at- position of
the windmill or helicopter blade, so say more ovoid
dimples at the distal part and more hemispherical
dimples at the near-rotor area. |
|
| |
Dimples at rotating blades could also have application to
better water propeller design, as well as better turbine
(like gas turbine) energy generation. Thanks [Voice]. |
|
| |
With modern 3D manufacturing and AI algorithms, dimples don't have to be uniform and can vary across surface. Even become holes. |
|
| |
I think I read about doing something like an air hockey table
to airplane wings to decrease turbulence and drag. All of
the numerous applications of [Voice]' idea (turbines,
propellers, helicopters, windmills) could possibly have
pressurized air/water/working fluid flowing out of holes to
decrease drag. |
|
| |
[bean] I think the air is sucked into the holes, so as to keep the flow close to the surface and stop it separating |
|
| |
Finding the right ratio of dimples (or better) could be
done with software, and might obviate dimples replacing
them with something like a streamlined hexagonal plane
tiling with mushrooms that dip down to U shapes (golf
ball dimples but better) to maximize laminar flow. A
wing or turbine blade covered with microripples. |
|
| |
Noting microripples I am reminded of a corduroy surface
wing or windmill that has all laminar flow, does the
heightened surface of the corduroy (microripples) cause
greater lift for a wing or turbine at the actual area of the
wing? |
|
| |
Undersurface channels between golf ball dimples (or
better) could connect golf ball dimples (or better)
together and make customized pressure profiles on
wing/turbine surface; one use is reintroducing laminar
flow to a turbulent area rearward on the wing/turbine.
Drones could wash the fussy little channels. |
|
| |
Now imagine it is the year 2040 and peltier effect
modules and MEMs refrigerators are 10-20 times better.
Select spots at the wing/turbine blade could be heated
and cooled to supercling the boundary layer or produce
controlled, directed turbulence. refrigerated-spot wings
could
have more lift from having a wider latitude of possible
shapes that conserve the boundary layer like high lift high
humps possible from the reduction in turbulent flow. |
|
| |
Ships of course could have dimples (or better) that are
hydrodynamic. |
|
| |
[Voice] One improvement to wind generator blades is
making them longer right on-site with additive
manufacturing/3D printing. The largest base size of
blade that can be transported is installed, and then
drones deposit and make extensions to the blade, perhaps
doubling its length. I read the longer wind turbine blades
are the more energy they harvest. Efficiency might go up
as well. |
|
| |