Aero Trailer? Could it help FE?

[bbjsw10]

I was thinking about building a small trailer to pull behind the Metro. It would be fairly light weight and used for camping supplies, fishing equip., etc.

I was thinking of building it using a method I seen using fiberglass. Build a wooden frame the shape you want the trailer, overlay with fiberglass and trim away wood frame after doing fiberglassing. I figured build it roughly 1ft shorter than my car and about 1 ft narrower, allowing airflow to attach to trailer.

Here is the shape I am thinking about.



Input? Just wondering if something like this could actually help FE at highway speed.

[metroschultz]

I believe so.
In one of bennelsons posts he talked about getting better fe with his trailer attached than without.
He tows a teardrop trailer similar to what you have drawn.
S

[Cd]

So if you have detached flow and then reattach further back, how does this affect drag ?
You still have the drag, but just not as much of it as you would had it not been reattached - right ?
I'm puzzled by this because the flow on the Lexus LS400/430 back glass gets detached, but is reattached on the trunk of the car.

[Cd]

You would also have to factor in added weight and rolling resistance.

[whokilledthejams]

I've been looking into what it would cost me to build something similar. Verdict: pretty expensive, but being able to haul extra junk now and then would be nice.

Lowering the effective cD of my car (what with the rear being vertical and all) would do wonders for me on the highway, where added weight is inconsequential, and the added rolling resistance wouldn't be too bad.

[Cd]

So ... who is going to be the first to build one ?

Um... nevermind.
Aerohead : care to share some thoughts on your trailer ?

I can't wait to see what we all come up with. I think it is a great idea.

[bbjsw10]

Originally Posted by Cd

So if you have detached flow and then reattach further back, how does this affect drag ?
You still have the drag, but just not as much of it as you would had it not been reattached - right ?
I'm puzzled by this because the flow on the Lexus LS400/430 back glass gets detached, but is reattached on the trunk of the car.

I was thinking on those lines as well.

On another note I was also thinking of making rear pieces that would "snap" onto car somehow. They would be much like what a semi has along the back of the cab. Or maybe incorporate these into trailer somehow.

Or maybe a double pivot tongue somehow to allow it to sit closer to car, but still be able to turn sharply.

[Bicycle Bob]

This sounds like a great project. I'd definitely go with the flaps to help seal the gap between car and trailer, making them from clear Coroplast to keep the lights visible. With gap sealers, the trailer front does not need careful rounding.

In boats, framless construction has become quite popular. You just cut out thin plywood to the shapes it would get trimmed to on a frame, and sew the panels together with wire. It takes a bit of propping up initially but after a few passes with the epoxy and fiberglass tape, and it is stronger than solid molded shapes. You can also do continuous 'glass for a super sandwich structure. see Stitch and Glue, or tack 'n' tape, etc.

[Bicycle Bob]

An alternative to gap seals attached to the car would be sections on the front of the trailer that would always just clear the car, being pushed back by the bumper against light springs. A V front on the trailer with two sets of hinges on the middle for the fairing sections would probably make a good setup, and bring the strength of the monocoque forward, close to the hitch.

[whokilledthejams]

Has anyone considered a single-wheel trailer? It could be build much closer to the tow vehicle, and can't be jackknifed!

Double Hitch Company

Motor Cycle Swivel Wheel Trailers