52 replies to this topic

[DavidGraves]

Howdy

 

I always assumed those station wagon wind deflectors were to help keep rear widow cleaner.

 

Many vehicle body shapes seem to carry a negative pressure at the trailing edge....witness the dirt on rear window after driving a dusty road.

 

Who'd have thunk ?

 

DG

[rubberlegs]

It’s fun playing around with an app like Wind Tunnel. I need to try a better drawing though!

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[DavidinPhx]

You may want to nerd out to this:

https://ntrs.nasa.go...20120000497.pdf

It’s NASA’s report on their research into truck aerodynamics …. I kid you not. 

 

Also this:  scroll down to post 248 for some real interesting graphics illustrating drag coefficients for various shapes and vehicle combinations. Searching  this forum brings up some more real interesting stuff. 

https://ecomodder.co...-t-7839-25.html

[ntsqd]

You may want to nerd out to this:

https://ntrs.nasa.go...20120000497.pdf

It’s NASA’s report on their research into truck aerodynamics …. I kid you not. 

 

Also this:  scroll down to post 248 for some real interesting graphics illustrating drag coefficients for various shapes and vehicle combinations. Searching  this forum brings up some more real interesting stuff. 

https://ecomodder.co...-t-7839-25.html

Page 66 of the above link has a paragraph about the vortex generators. Excellent link, thank you!

[kmcintyre]

Wow.... a lot of info/reading, etc.  Interesting too that they patented it.  I wasn't able to read all of it and went to the end to the "results".  I'll have to go back when I have more time and read it more closely but still not exactly sure what the final, best solution would be for our campers.  I've eliminated most of the gap between the cab and camper which I think helps but I'm sure there's more I can do.

 

 

You may want to nerd out to this:

https://ntrs.nasa.go...20120000497.pdf

It’s NASA’s report on their research into truck aerodynamics …. I kid you not. 

 

Also this:  scroll down to post 248 for some real interesting graphics illustrating drag coefficients for various shapes and vehicle combinations. Searching  this forum brings up some more real interesting stuff. 

https://ecomodder.co...-t-7839-25.html

[buckland]

I made mine out of 1/8" aluminum. 4" high.

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[JaSAn]

I made mine out of 1/8" aluminum. 4" high.

What improvement did you see?

[buckland]

quieter less buffeting, rear slide cab window airflow less noise and volume. I figure about a mile per gallon improvement. As I have  2 gallon Pax fuel (3) also in the space behind ...less turbulence. 

[DavidinPhx]

[Page 66 of the above link has a paragraph about the vortex generators. Excellent link, thank you!

Your welcome.

 

FWIW, I put a row of AirTabs across the back of the roof of my Ovrlnd Camper as a cheap experiment.  Didn't expect any MPG increase, but hoped for better dust control on my rear barn doors. Don’t think I got either dust or MPG improvement, but its so hard to say what works with all the variables. I did the AirTabs around the time I also regeared from 4.30s to 4.88s (on 21 Tundra). My mileage has definitely improved 1 to 1.5 mpg, but I attribute that almost completely to the regear. 

 

I may put the AirTabs down the sides of the camper to get better dust control, but dont love the look of either color (B or W) on the anodized aluminum skin of the camper. I’m sure they do a little something, but its not enough to overcome the giant square hole we’re all punching in the air!

 

Edited by DavidinPhx, 18 June 2022 - 09:04 PM.

[BlueSky]

Thanks for the report on the AirTabs. I was going to try them but there is not a lot of room to put them on the sides.  Recently I did a trip with a paddle board on the roof (Yakima racks) with the fins up (rocker curve down).  The back of the paddle board was about at the edge of the rear of the camper.  I got really good gas mileage on that trip. Maybe it was the way the air was channeled under the paddle board and directed downward at the rear of the camper. Perhaps a sheet of plastic at the rear Yakima crossbar angled down and ending just past the rear edge of the camper would do it. It will be an inexpensive experiment.