Anybody see these on the road yet? (Transport trailer add-on taper)

[Frank Lee]

Originally Posted by kach22i

This thread has evolved into a collection bin of various truck-like oddities, which is much to my liking.

Something to be said for variety and trying to learn from adjacent examples.

Did not early automotive aerodynamicists look at aircraft for inspiration?

Someone is going to have to explain to me what it is about any of that oddball truck/RV stuff that is aero and if there is something in there aero how does it apply to the real world; because I ain't seeing any of it.

[Sven7]

Originally Posted by Frank Lee

Someone is going to have to explain to me what it is about any of that oddball truck/RV stuff that is aero and if there is something in there aero how does it apply to the real world; because I ain't seeing any of it.

Colani is one of those people you employ to inspire the rest of the designers. He probably drops a lot of acid and you wouldn't want him to design the final production model. He does have some interesting ideas though, like the bullet nosed tractor and the integrated trailer. It's kind of a jumping off point for a more practical vehicle.

For the rest, I don't know what's supposed to be aero about them. Except the CFD one, which looks legit.

[Frank Lee]

This reminds me of the "Aerodynamic Bugattis" thread.

Yes, they are sleek.

They are swoopy.

They are beautiful.

But they aren't aero and those things don't make them so.

That said:

Pointyness doesn't automatically mean more aero.

Roundiness doesn't automatically mean more aero.

Covers and flares don't automatically mean more aero.

Wings and fins don't automatically lower aero.

Tipping windshields back don't automatically lower aero.

Cylindrical body cross-section doesn't automatically mean more aero.

************************************

In the real world trucks need to haul stuff. It's often big and heavy, and sometimes irregular shaped.

More often than not (for enclosed trailers) the stuff is on pallets.

It is loaded and unloaded via forklift on a loading dock. Docks are fairly standardized, such that they work for almost all trailers.

That means the trailer needs a flat floor, probably standard width, because that is how pallets and loads are sized.

The trailer floor needs to be at or near standard height so that the forklifts can go on and off. It is not realistic to expect forklift drivers to lug a heavy bridging ramp of some sort to cover a gap between a non-standard trailer and a dock. It is not realistic to expect the driver to throw ramps under the trailer tires to make up for height differences. It is not realistic to expect loading docks to be retrofitted with moveable ramps.

It could be somewhat realistic to fit trailers with adjustable height suspensions, if the cost/benefit ratio worked out. Then they could be lowered to some minor extent. Minor, because the trailer tires really are the limiting factor to a minimum load floor height, as unlike other vehicles, they can't intrude into the floor space (remember the forklifts). And also minor, if any, because the hitch on the truck and/or the truck suspension would need to go up and down accordingly to keep the trailer floor level.

The loading dock is the biggest reason huge stationary tailcones can't be fitted to box trailers. Oh, there are legal length restrictions too. But the main thing is to be able to quickly and easily swing open the trailer doors ALL THE WAY as in, 270 degrees swung open, so they are alongside the sides of the trailer, so the trailer can be backed into the more or less enclosed loading bay. Let me tell you, there oftentimes is not much for excess width in these bays. Any trailing device has to quickly and easily collapse or otherwise fold out of the way. Don't expect the driver to piddle with tools, or climb on top of the trailer, or any such thing. Don't expect the owner to pay for fancy hydraulics or servos or what-have-you either, unless the aero improvements are so great that it is money in his pocket.

[Shepherd777]

Frank I completely agree with 99% of your last post, but I would like to add to elaborate on the following two points:

Originally Posted by Frank Lee

It could be somewhat realistic to fit trailers with adjustable height suspensions, if the cost/benefit ratio worked out. Then they could be lowered to some minor extent.

The loading dock is the biggest reason huge stationary tailcones can't be fitted to box trailers. Oh, there are legal length restrictions too. .

Actually, Walmart, who does extensive Class 8 testing as most are aware, did it reversely. They built several low-boy van test trailers with smaller rear tires and wheels. They had vertical pneumatic actuators that raised the rear of the trailer to standard dock height to facilitate loading and un-loading.

Also, FMCSA allows up to 60" past the rear of the trailer for rear aerodynamic add-on devices. Although most all sold are 48" in length so they can be stowed behind the open doors, per one of your other points. The units that we will be selling in the spring will be a full 60" and stowable.

[Sven7]

Frank, notice I did not claim the Colani trucks are aerodynamic. I regard him more as an idea machine than anything.

[Frank Lee]

^Yup, got that.

[NeilBlanchard]

The MAN truck looks pretty aero and while it does affect the capacity, I think they ought to be tried to see how they work. Lots of trucks have many sizes and shapes of smaller packages, so just because it ain't rectangular, doesn't mean the cargo carrying is not practical.

[Shepherd777]

Originally Posted by wyatt

Future Truck would still benefit from a Kamm-Backed rear end, vs. the Bubble Butt it has now.

Shepheard, I don't suppose you have a "modification by modification" breakdown with improvement values for each, would you? Also, do you happen to have a copy (digital preferred, pictures fine, for sharing's sake) of those articles would you? Thanks!

Hi Wyatt -

Thanks for the kind words regarding following through.

Actually, what you are calling the "Bubble Butt" was the most aerodynamically clean boat-tail that our SolidWorks FloWorks CFD program has ever produced on a 53' dry van freight trailer.

I do have press releases, build pics, and a web site on the 1983 truck and the current SuperTruck being built. The SuperTruck is not finished yet, but we hope it will be ready for testing next month. So I'll probably start a seperate thread on the project in this aero forum of EcoModder, even though we use, like most folks here, more than just aero to get optimum fuel mileage. I just wanted to wait a little before revealing more details. If I get too involved and spend too much time in posting and replying to questions, I'll never get the damn truck finished.

[Frank Lee]

Originally Posted by NeilBlanchard

The MAN truck looks pretty aero and while it does affect the capacity, I think they ought to be tried to see how they work. Lots of trucks have many sizes and shapes of smaller packages, so just because it ain't rectangular, doesn't mean the cargo carrying is not practical.

I think the performance estimating calculators can give good estimates without needing a physical prototype. Then the question is, are such trucks/trailers usable and by how many i.e. 1% of trucking? 10%?

If the loads are so much shorter and perhaps lighter and perhaps they are loaded/offloaded differently i.e. crane or forklift or conveyor belt off the sides and not the end or whatever, why not trucks with the frontal area of cars but long like a train?

[JasonG]

MAN just might produce that truck. They are known for not following the norm.
If there was some compromise in the taper ov the van that was made up for with a tail extension, the load volume would only be minamally impacted.
Perhaps a lift gate type roof to have a full height loading opening ? Sort of like those "Aztec" SUVs have ?
The rest of the truch is close enough to their current models to only require new fiberglass not a full retool.