Utility trailer hack (building an aero enclosure for a 1100 mile highway trip)

[KamperBob]

Originally Posted by Cd

( Is that a typo ? I'm guessing that you really don't want to curve just one side of the side kammback extension, since that would cause the trailer to yaw back and forth. )

If I understand your question, you are asking which would be more beneficial - a curved roof line or curved sides.

From what I understand, curved sides are the winner, since you are working with twice the wind area.
Another benefit is visibility to other drivers ( since it doesn't slope down like a ramp ). Since the trailer is slimmer than it is tall, this will also mean that you might derive more benefit from it since the length doesn't have to be a great to come close to a teardrop shape.
The only drawback would be increased crosswind drag.

So did I understand the question O.K. ?

The question was rhetorical, actually. I'm not asking a community of experts for design advise. I'm just sharing my project. Folks are welcome to comment. Just don't be disappointed if I do my own thing anyway. It seems many might not appreciate how different this project is from typical car and truck mods, with very different goals frankly. Again, food for thought. I'm just trying to help others think outside the bun, if they want. It doesn't really matter to me. I am trying to make a contribution here. I think it's important for that to be clear. Judging from some of the responses, all of which I truly appreciate BTW, it seems like there may be some misunderstanding afloat.

Cheers
KB

PS- Typo fixed too. Tough crowd.

[Christ]

Originally Posted by KamperBob

The question was rhetorical, actually. I'm not asking a community of experts for design advise. I'm just sharing my project. Folks are welcome to comment. Just don't be disappointed if I do my own thing anyway. It seems many might not appreciate how different this project is from typical car and truck mods, with very different goals frankly. Again, food for thought. I'm just trying to help others think outside the bun, if they want. It doesn't really matter to me. I am trying to make a contribution here. I think it's important for that to be clear. Judging from some of the responses, all of which I truly appreciate BTW, it seems like there may be some misunderstanding afloat.

Cheers
KB

PS- Typo fixed too. Tough crowd.

I don't necessarily follow the top vs sides debate, because in my mind, the ultimate goal is whatever works best per application.

If you look around here, there are some mentions about top/sides, as well as some commentary by Phil (Aerohead) on exactly why the top is more important on most vehicles.

I don't want you to feel like I'm saying that you're doing something incorrectly, because I'm not. I don't know enough about the project, aerodynamics, or your background to make a comment like that. I was just adding to the conversation what I've seen/read and like to think I understand at least somewhat.

We surely understand that you're going to do whatever it is that you feel you need to do on this project, and it's yours to do in whatever way you see fit, but insofar as we shouldn't be offended by you not following our suggestions, I hope you'll not be offended by the input that comes of the thread.

I look forward to what comes of this, for sure.

[KamperBob]

Long day. No pix yet, sorry. The front is done minus some final security. The roof is on. One side is skinned. Other side framed. I'm about half through the 3rd 100-pack of screws. Better get more tomorrow. That'll be the biggest cost in this project. LOL

Cheers
KB

PS- Comments really are welcome.

PPS- I really do plan to get some pix eventually. This frankenhauler will have a short life but there will be some proof it existed.

[Frank Lee]

Rumpler did alright with a fairly flat top.

IMHO that generous a radius in plan view is more detrimental than a cube with adequate corner radii UNLESS the forward bulge of the radius is closer to the truck than the rounded cube would be. Two truths at play here: the smaller the gap between truck n trailer, the better; and larger radii than necessary for attached flow down the sides, on leading edges don't lower drag.

[KamperBob]

Frank escaped from his lair, and got his own web page.
FrankenHauler

Most technical details will live there. We can chat about it here.

Cheers
KB

[jime57]

Sorry KB to throw water on your good idea, but I don't think you get any payoff for a one time trip of 1100 miles. Small measures that cost money can't pay for that small exposure. Just pull a good tarp down tight over the load and that is good enough. I know this is the aero thread, but we don't want to get ridiculous ;-)

[Clev]

Originally Posted by jimepting

Sorry KB to throw water on your good idea, but I don't think you get any payoff for a one time trip of 1100 miles. Small measures that cost money can't pay for that small exposure. Just pull a good tarp down tight over the load and that is good enough. I know this is the aero thread, but we don't want to get ridiculous ;-)

Going from 10 mpg to 11 mpg saves 10 gallons, or about 25 bucks at today's prices.

[Whoops]

Regarding the top, I had a great learning experience. I built a car top that had a front which just continued the front windshield line up about 1.5 feet, then flat top and a flat back.

What I learned was accidental, but very relevant. I had some firewood I wanted to take, but we were out of room. So I put a tarp down on the top, stacked the wood on the tarp, at the back 1/3 of the carrier and roped the whole ensemble to the roof racks.

I figured I would be lucky to do 55 and pass a gas station. To my extreme surprise and delight, I was able to get about 22-24 miles/gallon in a car where my best mileage was around 24. It surprised the daylights out of me.

I would expect if you don't do something with the top shape, you are likely to get a lot of aerodynamic drag their.

[Frank Lee]

Now how did that thing come to be named Frank??? LOL

You probably know this bob, but what you'll need to succeed is a topper for the truck, and one that lines up with the height of the trailer will work the best.

[saddlsor]

I'm hoping to get some good ideas from this thread. I might have to pull a small trailer on a 2k round trip with a motorcycle on it. I've done it once before and my mileage went from a norm of 42 down to 30. this is using a honda civic as the tow vehicle. the trailer is just a mesh bottom and pretty light. trailer and bike together weigh 840lb.(about the same as 3 fat chicks so I'm thinking if I could pick up a few aero tips I could improve on that number.