Whale tubercles for trailing edge?

[aerohead]

Originally Posted by kach22i

Bumping this old thread, can we call this trickle down technology or just marketing?


https://www.ruppams.com/CatalogConte...VLS/HVLSRA.asp

*they might defend their claims with more science.
*it's a fixed-pitch fan,fixed angle of attack,non-tapered,non-twist blade design.
There shouldn't be any 'surprises'.
*I suspect that it's a sub-critical Reynolds number blade,all in laminar flow.
*blades don't stall at the tip.They stall over the aft-body portion of the blade on top.
*Whales and raptors actively morph their fins and wings as well as alter their entire body's angle-of-attack.The fan blades are 'static.'
* I think the acoustic argument is okay.Owls are virtually 'silent' fliers,using feather down and feather serrations to mitigate otherwise noise-generating vorticity as an evolutionary strategy.They can hear their prey,but their prey never hear them coming.

[kach22i]

Originally Posted by aerohead

*they might defend their claims with more science...................

Thank you for commenting.

It's a cool looking fan, for those that look upward that is.

Not as much function as first impressions would give.

I have seen overhead fans installed on exterior porches to keep mosquitos away with moving air.

I imagine that these fans struggle with natures breezes and microclimate conditions of being next to a building and under an overhang.

Under these conditions a tubercle fan may actually provide an advantage, but again I would need to see some sort of testing information before drawing a strong opinion.

[kach22i]

Didn't know where to dump this.

2010
Silent Helicopter Blades
https://www.trendhunter.com/trends/blue-edge

Cutting down on the 'blade-vortex interaction' that causes the loudness of helicopters today, Blue Edge works with another technology called Blue Pulse to combat that phenomenon.

According to Gizmodo, by adding 3 flaps to the edge of the Blue Edge blade, they "move up and down at 15 to 40 times per second, using piezoelectric motors that also help to reduce the blade-vortex interaction."

Video in link above.

[freebeard]

Similarly, I don't know where to dump this:

https://phys.org/news/2017-09-turbul...rs-plasma.html

Room temperature helium plasma jets modulated with sound waves.

When the researchers simulated the plasma jets, they found that the electrodes in the instrument—which are needed to create the electric field that makes the plasma—generate heat. This heat spawns a sound wave that travels out through the jet and along the boundary where the plasma meets the air, a layer that's prone to be unstable. The sound wave disturbs this layer, likely triggering turbulent plumes.

Now that this phenomenon is relatively understood, Kushner said, researchers can enhance or dampen this effect, depending on what's best for the patient. Ultimately, he said, this new analysis can lead to an approved and reliable treatment.

[kach22i]

Originally Posted by freebeard

Similarly, I don't know where to dump this:......

I reposted that article here:

Cool Science Story Of The Day [Continuing Thread]
https://phys.org/news/2017-09-turbul...rs-plasma.html

How about we start a thread called:

Aerodynamic Article of the Day (Continuing Thread)

It would be used for smaller items we don't want a dedicated thread on, and for things outside of traditional fluid bodies - perhaps.

Could include random images, like a breeze lifting up a persons hair or a skirt/kilt.................hurricane flipping cars...........

Random Aerodynamic Oddity of the Day.

Is that title above a better title?

How about this video of the wind pushing a dumpster on to a man in Russia?

Moscow storm catches a man by the dumpster.

https://www.liveleak.com/view?i=3c8_1496153911

Illustrates the power of the wind, maybe trash bins need to be aerodynamically shaped so they don't fly around?

[freebeard]

I'm for it but I think it should be general enough to encompass for instance the Shawyer EM Drive:

scirp.org:Sobolev Spaces, Schwartz Spaces, and a Definition of the Electromagnetic and Gravitational Coupling

[kach22i]

Originally Posted by freebeard

I'm for it but I think it should be general enough to encompass for instance the Shawyer EM Drive:

scirp.org:Sobolev Spaces, Schwartz Spaces, and a Definition of the Electromagnetic and Gravitational Coupling

Is that a hoax?

Schwartz Spaces?

Is this subspace stuff anything like anti-gravity or implosions?

Schwartz space
https://en.wikipedia.org/wiki/Schwartz_space

Looks to be real, and I'm way out of my normal space.

[freebeard]

Not to my understanding. More to do with

Versor Algebra by Eric Dollard

Eric Dollard's interpretation of Tesla and Steinmetz is that the inductance and reluctance in poly-phase AC is an actual shifting forward and backward in time of the components of what we describe with sine-wave hand-waving.

It's all above my pay grade too.

[Xist]

Algebra is attempting to calculate your ex, right?

[freebeard]

my ex- was calculating enough, thankyouverymuch.