Wind deflectors and Aero mods for fuel economy.

[DavidinPhx]

I have some practical experience with aerodynamic design as I raced recumbent bikes for awhile that had both front and rear fairings. A properly set up bike was noticeably faster or easier (better mpg, if you like) to move.

The big differences came from the rear fairings - essentially a tapered tear drop close against the seat to ease the transition of the air around the riders trunk and the hard edges of the seat back.

Anything that softens the edges of the square back of a camper will help a bit, but the challenge is our square rear ends are huge in proportion to any gains from softening the edges with a fairing, because we cant really make a tail box that’s a meaningful size.

You’ve seen the tail fairings on big rigs on the highway that look like a 1-2 foot angled strip on all four sides of the trailer rear. Those are actually enough to make a bit of a percentage difference in cost when used constantly over whole fleets. Our problem is something like that is very hard to rig and be able to use the camper.

Camper makers could help use out be by making the edges rounded even a bit, but thats a cost and engineering thing few will do. I think the splitters under the cab overs have some effect because they shoot the air past the hard leading edges of the camper.

Perhaps your SUP board does something similar at the rear.

 

[Vic Harder]

MPG is not the only reason to do this. Depending on the truck/camper the gap over the cab can create a lot of noise, and those splitters really help.

 

[BlueSky]

Noise = Energy

 

[buckland]

I'd love to "de-cake" (road dust) the back of the camper. It's astonishing how much clay/dust clings to the back. No way to get it off until a spray wash place. I am interested in the idea of a foil that keeps that to a minimum. Any wind tunnel engineers out there have ideas? The Jack Stand mounts do not help so I'd love to a bolt on foil there to reduce the drag and keep dust cling to a minimum.

 

[ntsqd]

I guess "splitter" is an appropriate term, but whenever I read it with regard to aerodynamic concerns I think of something like this flat plate:

I recall in the late 80's to maybe mid 90's there was one COE medium duty truck that had air deflectors on the front corners of the cab. They were fully integrated into the cab's design, and not an after-thought.

 

[Machinebuilder]

I'd love to "de-cake" (road dust) the back of the camper. It's astonishing how much clay/dust clings to the back. No way to get it off until a spray wash place. I am interested in the idea of a foil that keeps that to a minimum. Any wind tunnel engineers out there have ideas? The Jack Stand mounts do not help so I'd love to a bolt on foil there to reduce the drag and keep dust cling to a minimum.

https://seeiiairfoils.com/

That's the biggest claim this company makes.

 

[buckland]

Thanks for the link. I'll call and ask prices. I may end up making my own as I was thinking of using the rear Yakima bar.

 

[Machinebuilder]

post what the cost is, I haven't gotten around to calling yet

 

[buckland]

I have called three different state 'installer" dealers listed on their site and none of them knew who they were!

 

[Machinebuilder]

I've run into similar responses on other things.

 

[ntsqd]

When I couldn't find their product on the pages of a couple of their supposed dealers I quit looking and went back to designing my own.

 

[Machinebuilder]

I just sent a message from their website, lets see if I get a response.

 

[DavidinPhx]

This is another really good and fairly practical discussion on aerodynamics, though not specific to truck campers. I really like Superfast Matts videos, he tends to cut through the unnecessary stuff.