Foamie aerodynamics.

[angib]

Also, I wonder if a heavy spandex like stretchy fabric panels
would work in a similar fashion between the tow vehicle and trailer.

I think that is what Honda did with this one-off baggage trailer behind an Insight. The with-trailer drag was significantly less than the bare car - though they did add front wheel spats at the same time.

honda-insight-hybrid-micro-rv.jpg (97.75 KiB) Viewed 1817 times

[Wolffarmer]

Just how much does a square back cost in drag? Or a square back with flaps angling in? A couple days back I saw a semi trailer on the highway with angled in flaps on the back, top, sides and bottom. They where about 1.5 - 2 feet in depth. Looked like they where about 15degrees in. And a way to get them out of the way of the cargo doors. I do not believe I have ever seen them before.

Randy

Edit

Something like these

Trailer flaps

[Ned B]

Randy,
over on the Escapees HDT (Heavy duty truck) sub-forum there's a huge aerodynamic thread, and those were at least mentioned there. I've seen a few of those on one particular fleet's trucks, but not on anyone elses. I see the now-common skirts 'everywhere' though.

[Bogo]

California has a mandatory requirement for the skirts on all long haul semi trailers. After X date they will start fining $1000 a day if you don't have them on your semi trailer.

[mezmo]

...
over on the Escapees HDT (Heavy duty truck) sub-forum there's a huge aerodynamic thread...

Would you have a link to that ?

Cheers,
Norm/mezmo

[mezmo]

i think a spandex sock would measurably reduce drag though not as well as a solid surface. Could it hold up on th road? It works as a body sock for recumbent bikes but you"re.not going over 50 mph on bikes.

How about a UV protected 'big spandex sock' filler as an exterior, with a shaped to 'normal' dimension but flexible air-inflated balloon/bladder on the inside to give it a bit of "solidity" ? It'd only really bulge when doing lower speed sharper turns.

Cheers,
norm/mezmo

[GPW]

You know , we can talk about aerodynamics as much we want , but it all comes down to the application and practicality for the “boxes" we’re towing about the highways... We already know how to eliminate a Good bit of Drag , but the pursuit of even less drag usually involves more exotic methods with diminishing returns and increased complexity and expense ... all resulting in less space inside for you and your gear ... The Great Compromise !!!... Slant/ round what you can , smooth anything sticking out ... It’s still a Box eh ???

[Bogo]

It's fun to figure out materials and techniques that will allow a design to be built using simple construction techniques able to be done at home that will allow for a great degree of streamlining. It's the type of puzzle I like to solve. I never liked those silly word and number game puzzles. Instead of doing puzzles like that I spend my time solving real world problems like how to get a strapless, backless, classical little black dress to keep a 32II* bust covered while dancing up a storm. BTW, the original wearer's daughter, also wore it to her prom. Little black dresses are so timeless...

* Old style sizing. It'd likely be considered a 28K or 27KK bust now. Standing she had over 12" of difference between bust and rib cage measurements.

[mezmo]

I just came across this Aussie Off-Road Pop-Top Caravan.

I just love the exterior design in towing mode. But for its
astronomical price, it should have hard infill sides - but then
again, it is from an Off-Road Camper [Tent Trailer to us] manufacturer.

It is supposed to be, and looks to be, quite "aero". It's just missing
enclosed/skirted wheels, but then, that wouldn't be very practical
out in the Outback.

http://www.ultimateoffroadcampers.com.a ... /nautilus/

I just wonder how they manage that pull-out bed's cantilever... maybe
one-heck-of-a under-mount slide ?

An Homage in Foam should be possible, wouldn't you think ?

Cheers,
Norm/mezmo

P.S. The videos are quite interesting.

[GPW]

Norm , that should be easy to replicate that “shape" with foam ..... as mentioned elsewhere , it’s just an inverted boat ... A 2000lb. boat

[atahoekid]

It should be doable in foam, the shaping could be a PITA but you should be able to pull it off. Those Aussie trailers are quite interesting. See quite a few, many unique looks and thoughts

[mezmo]

'Just corralling another interesting aero posting on another thread
on the forum for here on the Foamie Aero thread:

Prem, in the Cargo Trailer Conversions section, has a thread -
"Re: A 12 ft. FEATHERLITE conversion". On page 49 of it, he has
a post regarding some aero TT designs with links:
viewtopic.php?p=1040072#p1040072

The specific link with some new info that prompted this reference
posting is for a new rear fairing design:
http://www.trailerinnovations.com/

[mezmo]

As usual, I came across this just by tootling around on the web
looking for something else.

This is about the Glenn Curtiss Aerocar 5th wheel Travel trailers
of the 1920s and 1930s. He was a very imaginative aircraft designer
and builder in the early years of aviation and utilized his aircraft
design principals in his trailer designs. Read that as light and 'aero'.
The trailer pics begin about a third or so of the way down on the right.
Notice how very aerodynamic the trailer body designs were on some
of them [and the one motorhome design shown] with their rear ends
having a complete taper on them. And all used generous radii on the
section joins/edges as well.

http://www.coachbuilt.com/bui/c/curtiss/curtiss.htm

Just by coincidence also, I had gone to the Glenn Curtiss Museum
in Hammondsport, NY last summer. A most interesting small museum.
They had one of the later Aerocar 5th Wheel trailers and it's tow vehicle
on display, among all the various motorcycle and aircraft displays.

Cheers,
Norm/mezmo

[Ned B]

Norm,
very cool link, thanks! I'll have to take a ride out to Hammondsport one of these days and look up that museum.

Way back in the late 80's to mid 90's I traveled across the USA. For a couple of years I stayed in hotels, but eventually I decided that I would rather have an RV. I bought a pickup truck and a 5th wheel made by Shadow Cruiser out of Elkhart, IN. It was what I would call an entry level unit, typical stick and staple construction, etc... but the one thing that I really enjoyed was that instead of the 'normal' boxy nose, it had a very aerodynamic front end:


That isn't my trailer, but I can attest that that nose design worked Very well. It hung out in the slipstream of the pickup, and while I noticed the trailer was there of course, it was relatively easy to tow. I wouldn't buy another of those trailers these days due to their construction, but the aero part worked as designed. I lived out of that trailer for 3 years on the road.

Shadow Cruiser also made slide in campers for pickups, which had a similar nose cone. their interiors were nothing to write home about, all Luann and so forth. The company ultimately went under during the manufacturer bust a few years back. Someone re-started the brand, and they now make typical travel trailers with rounded nose profiles.

[Ned B]

...
over on the Escapees HDT (Heavy duty truck) sub-forum there's a huge aerodynamic thread...

Would you have a link to that ?

Cheers,
Norm/mezmo

Norm, sorry, I didn't see this reply back in the day. I'll dig around over there, but the admins are fairly draconic lately, and a LOT of threads are locked and/or deleted.