Tuft Testing - "Vortekz" vortex generators on 2003 Jetta Rear Window

[Kyleyadon]

It was chilly and humid when I went to work the other day, so the car was covered in condensation. When I stopped for gas I looked at the way the airflow had affected the moisture on the car, and took some pictures with my cell phone. Sorry they're not very good, but it's a cheap phone that I only have because I need it for work. But what seems to be going on is that the airflow over the roof is about what you'd expect, until about three inches from the back glass, which is where the roof curves down to meet the back glass, at which point the moisture on the roof is completely undisturbed. The moisture on the back glass is likewise completely undisturbed. In fact it's not until you get to about the middle of the trunk lid that the moisture shows signs of airflow again. Which would seem to indicate that the airflow is detaching from the roof at the point where it begins to slope down towards the back glass and does not reattach until approximately the middle of the trunk lid. Which presents the question: Is it better to encourage the airflow to remain attached, such as with some VGs? Or is it better to encourage the airflow to remain detached by putting some sort of extension onto the roof so that the downward moving air misses the back of the car entirely?

[Kyleyadon]

Originally Posted by aerohead

here,you can see Pininfarina doing this with the CNR car they developed between 1976 and '78

here,GM use lamp-black and kerosene to sort out their 1963 Sting Ray

Makes you wonder where cars would be today if car makers had continued along this line of development. Since cars became decidedly less aerodynamic in the late 70's early 80's and it seems that only now, over the last ten years or so, have they started getting rounded out and made more aerodynamic again.

[freebeard]

I'd say just the opposite. Review this: An Illustrated History Of Automotive Aerodynamics: Part 3 (1960 – Present)

The 80s is the 'jelly bean' era, precipitated by the Ford Taurus/Mercury Sable. The first American cars with the headlight reflectors mounted in aerodynamic buckets, following (of course) the VW Beetle in the 30s.

Contemporary cars have lost the 'jelly bean' look, especially in the back, and have more sculpted sides.

As for your question posted three minutes earlier; depends on the installation, a Kammback is probably the winner.

[Kyleyadon]

Originally Posted by freebeard

I'd say just the opposite. Review this: An Illustrated History Of Automotive Aerodynamics: Part 3 (1960 – Present)

The 80s is the 'jelly bean' era, precipitated by the Ford Taurus/Mercury Sable. The first American cars with the headlight reflectors mounted in aerodynamic buckets, following (of course) the VW Beetle in the 30s.

Contemporary cars have lost the 'jelly bean' look, especially in the back, and have more sculpted sides.

As for your question posted three minutes earlier; depends on the installation, a Kammback is probably the winner.

You're probably right, on both counts. But I was thinking about how cars went from being rounded and sleek, to boxy and angular. I've got a '74 Buick Apollo, and while compared to either of the vehicles pictured above, it's a brick, compared to my grandmother's '83 Chevy Impala it possesses a dart like sleekness. And the difference is even more pronounced when looking at SUV type vehicles. An 80's era Jeep Grand Cherokee looks like a box on wheels, while the current 2017 Jeep Grand Cherokee looks like it was modeled after a space craft from some futuristic sci-fi series, very sleek and aerodynamic.

I agree about the Kammback, and I think that in the near future I may build a test model out of cardboard, with the miles I drive every day it shouldn't take long to get an idea as to how well, or poorly, it's working.

P.S. The Aptera, pictured in the article you shared, looks a lot like the Elio that just started selling this year.

[gone-ot]

Originally Posted by Kyleyadon

[snip]...
P.S. The Aptera, pictured in the article you shared, looks a lot like the Elio that just started selling this year.

HAVE they actually *sold & delivered" ANY vehicles yet?

[Kyleyadon]

Originally Posted by Old Tele man

HAVE they actually *sold & delivered" ANY vehicles yet?

On further investigation, no they have not. In fact despite the 65k+ paid reservations, they've pushed the launch date back to 2018 and are claiming financial problems as the reason why. What a shame.

[freebeard]

The thread on this runs 172 pages since 2013-01.

http://ecomodder.com/forum/showthrea...ing-24513.html

[aerohead]

Originally Posted by aerohead

here,you can see Pininfarina doing this with the CNR car they developed between 1976 and '78

here,GM use lamp-black and kerosene to sort out their 1963 Sting Ray

Looks like Photobucket has changed their services and I can no longer share or link any of my 71-pages of aero images without paying them an annual fee.
At first blush,I can't conceive of paying out any new expenses.After Medicare kicked in,my monthly income is equivalent to around $4/hour.

[aerohead]

Originally Posted by Kyleyadon

It was chilly and humid when I went to work the other day, so the car was covered in condensation. When I stopped for gas I looked at the way the airflow had affected the moisture on the car, and took some pictures with my cell phone. Sorry they're not very good, but it's a cheap phone that I only have because I need it for work. But what seems to be going on is that the airflow over the roof is about what you'd expect, until about three inches from the back glass, which is where the roof curves down to meet the back glass, at which point the moisture on the roof is completely undisturbed. The moisture on the back glass is likewise completely undisturbed. In fact it's not until you get to about the middle of the trunk lid that the moisture shows signs of airflow again. Which would seem to indicate that the airflow is detaching from the roof at the point where it begins to slope down towards the back glass and does not reattach until approximately the middle of the trunk lid. Which presents the question: Is it better to encourage the airflow to remain attached, such as with some VGs? Or is it better to encourage the airflow to remain detached by putting some sort of extension onto the roof so that the downward moving air misses the back of the car entirely?

It depends.
Hucho suggests that for the optimum drag reduction,you'd convert the notchback to a Kammback.
However,there is evidence that it's not a one-size-fits-all solution.
Evidently,we'd have to consider each vehicle on a case-specific basis.And there's no apriori way to predict any specific outcome.Which sucks!

[freebeard]

Looks like Photobucket has changed their services and I can no longer share or link any of my 71-pages of aero images without paying them an annual fee.

https://www.google.com/search?q=photobucket+3rd+party+hosting

PCMag reports it 6hrs ago, Ghacks Technology News 9hrs ago.

If you still have access of your own, it's not ransomware. Be looking for a download manager or utility to suck down everything behind your log-in page.

https://www.google.com/search?q=website+downloader