12-21-2020, 03:08 PM
|
#1 (permalink)
|
Banned
Join Date: Nov 2017
Location: Australia
Posts: 2,060
Thanks: 107
Thanked 1,605 Times in 1,136 Posts
|
External air curtains
Throttle stop drag tested, tuft tested and pressure tested. The most effective 'simple' modification for measured drag reduction that I have done.
|
|
|
The Following User Says Thank You to JulianEdgar For This Useful Post:
|
|
Today
|
|
|
Other popular topics in this forum...
|
|
|
12-21-2020, 03:47 PM
|
#2 (permalink)
|
Master EcoModder
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,704
Thanks: 7,778
Thanked 8,586 Times in 7,070 Posts
|
The best candidate I've seen, from Ecomodding Central. I suggested he search on 'edgarwit':
https://ecomodder.com/forum/showthre...eas-38904.html
__________________
.
.Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster
____________________
.
."We're deeply sorry." -- Pfizer
|
|
|
12-21-2020, 06:04 PM
|
#3 (permalink)
|
Master EcoModder
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 4,158
Thanks: 120
Thanked 2,790 Times in 1,959 Posts
|
Quote:
Originally Posted by JulianEdgar
The most effective 'simple' modification for measured drag reduction that I have done.
|
Awesome.
I appreciate you trying new things and testing them rather than dismissing them as something only large corporations with vast resources and staff of professionals can do.
|
|
|
The Following User Says Thank You to kach22i For This Useful Post:
|
|
12-22-2020, 04:54 AM
|
#4 (permalink)
|
-----------------
Join Date: Jun 2009
Location: Romania
Posts: 128
Thanks: 22
Thanked 57 Times in 44 Posts
|
Quote:
Originally Posted by JulianEdgar
Throttle stop drag tested, tuft tested and pressure tested. The most effective 'simple' modification for measured drag reduction that I have done.
|
And why does it look so ugly? The modifications must be applied in such a way as to be related to the current design of the car. It's like they're taken from the truck ...
I would have chosen the solution inspired by Mercedes-Benz A-Class/C-Class.
|
|
|
12-22-2020, 05:12 AM
|
#5 (permalink)
|
Banned
Join Date: Nov 2017
Location: Australia
Posts: 2,060
Thanks: 107
Thanked 1,605 Times in 1,136 Posts
|
Quote:
Originally Posted by IRONICK
And why does it look so ugly? The modifications must be applied in such a way as to be related to the current design of the car. It's like they're taken from the truck ...
I would have chosen the solution inspired by Mercedes-Benz A-Class/C-Class.
|
Well when you do so, you can show us the results.
|
|
|
12-22-2020, 12:05 PM
|
#6 (permalink)
|
Master EcoModder
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,704
Thanks: 7,778
Thanked 8,586 Times in 7,070 Posts
|
Quote:
And why does it look so ugly? ... It's like they're taken from the truck ...
|
That's a section of aluminum extrusion. I consider it proof of concept.
__________________
.
.Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster
____________________
.
."We're deeply sorry." -- Pfizer
|
|
|
12-22-2020, 04:09 PM
|
#7 (permalink)
|
-----------------
Join Date: Jun 2009
Location: Romania
Posts: 128
Thanks: 22
Thanked 57 Times in 44 Posts
|
It is totally useless in this case. An aluminum (or any other material) sheet does the same thing.
|
|
|
12-22-2020, 04:16 PM
|
#8 (permalink)
|
Banned
Join Date: Nov 2017
Location: Australia
Posts: 2,060
Thanks: 107
Thanked 1,605 Times in 1,136 Posts
|
Quote:
Originally Posted by IRONICK
It is totally useless in this case. An aluminum (or any other material) sheet does the same thing.
|
You'll have to show us the results of your testing - this is an interesting area.
Vman455 told me he used sheet metal for external front air curtains and recorded a drag increase on his Prius - but they gave much better stability when passing trucks.
As I say, I'd love to see the results of your tests.
|
|
|
12-22-2020, 04:39 PM
|
#9 (permalink)
|
Moderator
Join Date: Feb 2012
Location: Urbana, IL
Posts: 1,937
Thanks: 199
Thanked 1,802 Times in 939 Posts
|
Quote:
Originally Posted by JulianEdgar
Vman455 told me he used sheet metal for external front air curtains and recorded a drag increase on his Prius - but they gave much better stability when passing trucks.
|
Yes, this is correct--the sheet metal front ducts by themselves appear to increase drag based on fuel economy testing. But when I compared pressure difference on each side of the car just behind the front wheel arches (at Julian's suggestion--thanks!), I found that the average pressure difference between sides in a 25 mph crosswind was nearly 15% lower with the ducts on. The wing sections seem to be a better solution, and something I'll probably try in the future.
|
|
|
The Following User Says Thank You to Vman455 For This Useful Post:
|
|
12-22-2020, 05:08 PM
|
#10 (permalink)
|
Master EcoModder
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,704
Thanks: 7,778
Thanked 8,586 Times in 7,070 Posts
|
Can you post a comparison of the two approaches?
I speculate that a flat plate would have critical angle-of-attack and positioning criteria. I further speculate that a curved plate would approach the result of the airfoil section.
I've been thinking about air curtains on a Geo Metro. It looks like I could add a partial diverter on each side (flushed out to the upper bumper) with curved plates capping the void created.
__________________
.
.Without freedom of speech we wouldn't know who all the idiots are. -- anonymous poster
____________________
.
."We're deeply sorry." -- Pfizer
|
|
|
|