Morelli's 'Fluid Tail'

[aerohead]

Originally Posted by freebeard

The all-forebody car is an interesting concept. For the interior packaging.

The Punto's Kammback addition has an interesting semipermeable and perforated screen attached.

It would be a very good thing to see this research fleshed out with numbers provided.It's 2016,so a decade and a half have passed with no word perhaps.
Cold case.

[aerohead]

Originally Posted by rumdog

This is a super interesting paper aerohead. Lots of good stuff...

*centrifugal fan rims! Well of course! Then pumping the air into the wheel wake to fill in the ring. Genius.

*the shape of the vehicle shocked me a bit, but it is designed with neutralising cross winds in mind among other factors.

*underbody flow is also key to completing the ring vortex

*3 pairs of voticies coming off each wheel, wow! Go wheel skirts!

so if you did use these fan wheels on the front, where close by would you pump the flow? Behind front wheels?




I think this ends the debate of air dam vs smooth underbody.

The front wheels probably aren't candidates for the technology, since they must articulate through their entire range of wheel-flop, as automakers refer to it.
The inner wheel face would just be too far from the inner fender wall ducting when centered, losing all available pressure to the gap.

[aerohead]

Originally Posted by MeteorGray

With the spermatozoon tail, I'll bet it's a handful in a strong sidewind.

Professor Morelli's research has always taken high-speed directional stability into consideration. His 1973 patent (application 1964) included stability as a cornerstone of the design protocol.
His 'banana' car of 1978 used fin/fairings behind the rear wheels to control the center of pressure, providing for 'slip' without 'yaw.' Zero pitching moment as well.Zero lift.

[aerohead]

Originally Posted by sendler

So a knife edge termination to a concave cavity is key in setiing up the swirl of a fluid tail.
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we are already starting to see this concave treatment of the truncation on hatch backs with their "visor" following the roof line to hang over the rear glass. And the sharp termination of the side lines at the rear bumper falling away at a sharp right angle to the "step" lift over area at the rear access.
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*The important thing is that the separation line be transverse, and circular or elliptical.The Prius shown would not qualify.
The 2010 KIA Ray,PHEV concept would probably be good recent candidate.
*The concavity isn't important either.
*The ramp angle of the ring-vortex generator may be critical,although Morelli's research, as of 2000, is not mature enough to say.

[aerohead]

Originally Posted by sendler

Here is a company making side view mirrors that feature an inner "oval spoiler" to create a fluid tail.
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Race Mirrors: Professional Extreme - advanced aerodynamics
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Unless we get camera systems to replace our mirrors,your race mirrors are the solution. They'll be going with me to the wind tunnel in September.

[freebeard]

*The important thing is that the separation line be transverse, and circular or elliptical.

Maybe the cut-out for visibility is mitigated by being within the influence of the main body.

*The ramp angle of the ring-vortex generator may be critical,although Morelli's research, as of 2000, is not mature enough to say.

For every optimal ramp angle there will be a corresponding step transition? Does the step have any advantage over a ramp?

[lowglider]

Guys, what do you think about this tail that mother nature made from snow? If the timestamp doesn't work, it's at 7:00.

https://www.youtube.com/watch?v=jmAtsPiN3gw#t=7m0s

Has a similar approach to improving the rear ever been done in a wind tunnel? I mean getting a snowlike but more sticky substance and let it shape itself on the rear.

[freebeard]

Spray-on foam and a sandblaster instead of a smoke wand? Maybe you could spray the foam wet and left it solidify in the wake.

I suspect the reason the picture that appears on the laptop in the 40 minute video shows so much symmetry is that the car is down in a street grid that channelizes the air so there is no gusting, and the car is parked nose into the wind.

http://ecomodder.com/forum/showthrea...ure-11745.html

[aerohead]

Originally Posted by freebeard

Maybe the cut-out for visibility is mitigated by being within the influence of the main body.



For every optimal ramp angle there will be a corresponding step transition? Does the step have any advantage over a ramp?

*You'll have to help me with what you mean by 'cut-out.'
*As far as ramp vs step,we'll have to wait for a follow-on report from Morelli.He provides no specific information in the 2000 paper.

[aerohead]

They're all fun to look at,and I suspect that many would generate some interesting drag coefficients.
Ice has been used in a wind tunnel in an attempt to let the moving air sculpt it into a low drag form,but there were erosion problems.
If you tried to use snow in a tunnel,the leading edges of the drive fan would have to be remote,and protected from anything but air touching them.