Minimizing Aerodynamic Effect for Trailer Towing

[ByDesign]

Everything has trade-offs . . . efficiency / utility / aesthetics / availability / cost / storage ...

This is the project, and the goal is to improve towabiltiy and economy. The constraints are the usual (cost, time, availability of pieces, ...) then, add aesthetics and functionality.





Background: For work I sometimes attend events that require a lot of "stuff". I've outgrown the truck, so added a trailer. Couldn't find what I wanted, couldn't afford custom, don't have time to build it, so finally opted for this. Got a good deal, so this is where I start.

Now I'm thinking mods just for fun to see what it can become, but I'm constrained --- have to face realities --- aesthetics are important because it's part of the company presentation (outdoor events and will have company logos), and functionality (must be easy to use). I'd love to tape it all up, unfortunately, a lot of people are quick to judge . . .

I appreciate suggestions -- with a focus on practicality (see above constraints). Boat tails, for instance, though good for drag reduction, have practicality issues when long enough to be effective. I'd like your help thinking through mods that can look nice as well as be functional, practical, cost effective and efficient.

I'd love to see any examples of what you've done too. I have a bunch of ideas, but I'll insert them later.

Thank you, in advance, for your suggestions. This should be fun ... not just with the discussion, but also in the doing!

[botsapper]

http://ecomodder.com/forum/showthrea...tml#post236561

[ByDesign]

Yes, Thank you. I have read that thread and love the idea of a completely streamlined trailer, unfortunately not in the time or financial budget. I love much of what was in that thread and especially some of the posts from aerohead and skyking.


Off the bat, the hit for towing the trailer home (empty just after I purchased it) was around -2 MPG. Not huge, all things considered, and not very scientific (based on a one-way trip of 50 miles).

I'll post more about the first "real" trip when I get the info complied. Driving along gave me lots of time to think, and the mods are stewing in my head.

[jakobnev]

I suspect simply radiusing the front of the trailer and adding a box cavity to the rear of it, would give the most bang for the buck.

[aerohead]

If you have an awning company nearby,they could roll-form square aluminum tubing and heli-arc it into a skeleton framework for an aerodynamic nose which would resemble an Airstream or W-W 2-horse stock trailer.
This framework could have aluminum skin riveted on and painted to match the trailer.
The same company could also make you skeletons for the wheel fenders,to create lower drag fairings.
Short of composites,I can't think of a more direct route to drag reduction which also addressed your aesthetic considerations.

[freebeard]

Welcome to Ecomodder!



I posted this picture a while back and someone actually implemented it on a travel trailer. I think he used 4" stovepipe, the split kind, unrolled and attached to the front edges of the trailer. It's a way to get the radiused edge without intruding into the box.

Beyond that, race car wide-body fenders over the stainless steel ones. And see if you can channel the air from under the tow vehicle to under the trailer, or at least divert it to the sides.

[ByDesign]

Aerohead, I love the idea with the awning company. I love it particularly because I've already been to a local company to discuss exactly that. I have not decided yet on what direction to go, but that is high on the list.

I had not considered also having them do something over the wheels and fenders. Thank you for that addition. I think that's a pretty cool idea.

Also, Freebeard, the half pipe thing sounds interesting. Do you know of anyone who has actually done that? And, what was the result?

[ByDesign]

OK, here's the info. First "real" trip was 199.2 miles. The only mod done for the first trip was to lower the hitch (level out the trailer and reduce frontal area).

The drawbar in the first post photo above has a 2" drop, this one has a 4" drop. It needs a touch more, and I have an 8" drop, but that seems a little too much.



The total for the first trip was down 2.2 MPG from normal, but that's not the whole story. The truck is a 4.6L manual trans and generally very capable. By itself, loaded, it holds 75+ MPH on the highway for this route without a problem.

This is Colorado, so there are lots of hills (and satisfying descents), of course, but with the trailer, there were several times climbing it struggled to hold even 65. Certainly added weight is a factor (+900#), but I think the aerodynamic load is killer. (I have a long flat bed trailer I've pulled with a lot more weight and it doesn't have nearly the drag of this sail.)

OK, the understatement is "Go slower." I understand the V^2 contingent -- which is, one of the conflicts because time is also important. Anyway, next step is to try a few aero mods. I've got one in mind that I think you'll like.

[botsapper]

Trailer wheel covers, aftermarket folding trailer wind deflectors and box trailer nose cones. DIY boxed-in trailer wheel fenders and mod your own folding trailer boattail panels.

Interesting front nose cone or gap fairing. http://www.freightwing.com/common/im...ap_fairing.jpg

http://cdn2.bigcommerce.com/server90...0.1280.jpg?c=2

http://www.nosecone.com/images/home_r4_c3.jpg

http://www.surfbus78.pwp.blueyonder....images/TT1.jpg

http://www.ewals.com/media/480028/Tr...-5_450x338.jpg

[freebeard]

Two posts 12 minutes apart? If no-one else has posted, just click Edit and add to the first one.

Also, Freebeard, the half pipe thing sounds interesting. Do you know of anyone who has actually done that? And, what was the result?

I was hoping someone else would chime in, but since you ask I made the effort. Searching on 'trailer front edge radius' for instance didn't work. Searching on the picture title turned up zero (doesn't search inside HTML tags?) Believe it or not, I finally hit pay dirt with 'Wurlitzer juke box'.


http://ecomodder.com/forum/showthrea...tml#post481517

If you can't sort out the details, PM Hersbird, it's his trailer.