Project number 2 for this month, Aero Trailer!

[todayican]

I am gettin excited about building some aero stuff!

Getting the F-150 to do patterns, prototype and testing this weekend, and already looking forward to the next product to develop :-)

I was looking at an old post and something jumped out at me, it was the image indicating the various cds of following a car and towing a trailer, the lowest portion made my jaw drop! .31 cd to .12 cd!

Any how, Ive had another idea for a while, to build a "pusher trailer" and installing an ev motor - Or 10hp diesel - Or both. (the Diesel would be on a clutch and only be used for droning down the highway right in its effeciancy "sweet spot"

And or just the Diesel and a gen head and use it as a range extender for pure EVs.

Some neat ideas I want to monkey with are:

making the tongue variable length and deploying it based on vehicle speed (over 45mph it would "tuck" in close to the car, under 45 when more clearance is needed for turns etc, it would extend 20 to 24 inches.

Figuring out a good looking, removable, and effective gap seal for the tow car to REALLY make the aero work.

Seeing if I can get the damn thing actually built in the next 2 weeks :-)

So again, I ask: Input, suggestions, ideas, criticisms?



So again, I ask the gurus what they think

[GRU]

Trailer looks good. That can be built pretty cheap too and can attach to many different cars

[aerohead]

Originally Posted by todayican

I am gettin excited about building some aero stuff!

Getting the F-150 to do patterns, prototype and testing this weekend, and already looking forward to the next product to develop :-)

I was looking at an old post and something jumped out at me, it was the image indicating the various cds of following a car and towing a trailer, the lowest portion made my jaw drop! .31 cd to .12 cd!

Any how, Ive had another idea for a while, to build a "pusher trailer" and installing an ev motor - Or 10hp diesel - Or both. (the Diesel would be on a clutch and only be used for droning down the highway right in its effeciancy "sweet spot"

And or just the Diesel and a gen head and use it as a range extender for pure EVs.

Some neat ideas I want to monkey with are:

making the tongue variable length and deploying it based on vehicle speed (over 45mph it would "tuck" in close to the car, under 45 when more clearance is needed for turns etc, it would extend 20 to 24 inches.

Figuring out a good looking, removable, and effective gap seal for the tow car to REALLY make the aero work.

Seeing if I can get the damn thing actually built in the next 2 weeks :-)

So again, I ask: Input, suggestions, ideas, criticisms?



So again, I ask the gurus what they think

If you haven't read everything already on the internet for Range Extender Pusher trailers you'll want to do that.Especially Mr.Sharkey's Porsche 944 / VW RXT-P.
AC Propulsion Inc. has done a number of 'wake-rider' RXT-G trailers which you may also want to inspect as well as the all-new PRU RXT-GP Diesel pusher.
To get the lowest drag you're gonna need all-compound surfaces which require massive amounts of man-hours to fabricate ( I'm in over 800-hours on mine so far ),so I don't know about your 2-week target.
The telescopic tongue feature will require some clever engineering especially for the gap-fillers.
My gap-fillers are on the trailer itself and there is a symbiotic reinforcement feature do to this placement which really helps when striking killer pot-holes 'n such,and in 'roll.'
If you have a Scan-Gauge or such,you might cobble up a prototype trailer body and 'road-proof' it as in the JEEP Cherokee vs Prius comparison on the Stunt-Busters You-Tube clip.

[todayican]

Thanks for the input AeroHead!

Im somewhat familiar with the pusher trailers over the years (maybe aware is a better phrase, never drove with one etc)

I have the misfortune of having done a few car bodies from scratch, lots of cheese graters and foam, which is what may well happen with this one, BUT I have been doing a LOT of research into 3d routering and the concept of having it built in cad then "cut" in slices in wood, assembled, sanded and voila, trailer body mold (almost)

I think the articulation will actually make the gap filler easier to excecute. when its in "town mode" at lower speeds the gap filler would essencially be obsolete, but when she tightens up toward the car, less gap to fill.

I think this week I will do an unpowered "boxy" one with somewhat square sides with sanded edges to measure FE increases or deficits, then work on the power part.

Id love to hear your guess on increase on an otherwise modified prius c, and or unmodified 2004 Pontiac vibe with good gap seals? :-)

[Stan]

Originally Posted by aerohead

If you haven't read everything already on the internet for Range Extender Pusher trailers you'll want to do that.Especially Mr.Sharkey's Porsche 944 / VW RXT-P.

I especially liked Mr Sharkey's Rabbit-on-Rabbit range extender from back in the day.



The rear Rabbit was, IIRC, a non-turbo diesel with an automatic trans that he could control shifting, ignition and fuel from the front car's driver's seat. It had some reliability and driving issues as I recall, but it was a definite view to the future.

[oil pan 4]

If you are going to use a diesel generator why not put it on or in a trailer hitch cady?
That way you don't have an extra set of wheels, no trailer to register and pay for, no low hanging stuff to mess up under vehicle aero any more than it already is.

[skyking]

What is the Tow Vehicle (TV)? I can engineer you up a sliding tongue system, I think it is a great idea. Put an open Kammback "receiver" fairing on the TV and pull the trailer up into it.
Couple the mechanism to the TV's Vehicle Speed Sensor (VSS), so it will automatically move as you indicated, but progressively. Reality is you will not see more than a couple of degrees deflection above 25 MPH, so engineer for that. If you want to be sure, build a test jig and go driving and you'll see.
I'd design it so it will work automatically, but will be easy to override manually in case of a malfunction. I'd install a pair of sensor bars to let you know before you start bending things.
It combines a couple of very easy things, since the trailer can now have simpler front.
Open Kammback is also simple.
Why are all the cool projects clear across the country?

[Stan]

Originally Posted by skyking

Why are all the cool projects clear across the country?

Because you live in a hell-hole that is the Detroit of the west?

[skyking]

You can keep the bay area. I live far out in the sticks about half way to Mt. Rainier. :P

[skyking]

If the trailer is an appropriate weight, the CG/tongue weight shift will be beneficial too.
Lighter tongue weights at low speeds are more maneuverable but not stable at speed. Not a problem with this concept.