AeroTruck

[vtec-e]

Originally Posted by Abner

I think this is not real, It's FAKE

Not fake actually. I passed one a few weeks ago and looked it up. Here is a thread i posted on it:http://ecomodder.com/forum/showthrea...cks-14375.html

And a link to Don-Bur:M and S Cuts Carbon With Teardrop Trailers*
And a road transport site:Don-Bur 'Teardrop' box trailer aero kit
And a closer pic:http://www.donbur.co.uk/gb/images/te...iler-fbulk.jpg
It's pretty cool actually. More of this is needed.

edit: they use this stuff called "technolite" to skin the trailer:DON-BUR: Lightweight Panel Options
I daresay it is a hot competitor to coroplast! Did i say that??!!

[Abner]

Originally Posted by euromodder

How high is your truck design ?

Don-Bur is British, so they also have to keep within 4m.

My truck design is 4m high. It's designed to maximize carry load AND aerodynamics. The CFD simulation show a Cd = 0.12

[DON-BUR]

Originally Posted by aerohead

The photo of the tractor-trailer is not real,yes? I've seen enough actual and photographic windtunnel smoke investigations that I'm highly suspect of the authenticity of this image.

We would like to clarify that this illustration is NOT an actual windtunnel photograph - as many here have deduced.

This is an illustration and mark it clearly as such.

Nevertheless, as also pointed out here, the illustration is based on CFD work and further anlysis. The problem that we had was full-scale wind-tunnels and attempting to get a decent photograph - which proved impossible: hence the illustration.

We are fascinated by this design and a claim of CD 0.12 is quite staggering. However the design at the front needs revising.

The lower skirts are shown to extend forwards around the wheels of the tractor unit. This is not practical due to articulation.

For guidance, the standard ISO swing clearance for the tractor, rearwards of the kingpin is 2.3m.

General measurements for guidance...

Forward maximum swing clearance to front of trailer (as a radius from kingpin) is 2.040m

Maximum length from kingpin to trailer rear: 12.0m

Maximum width (dry freight) 2.55m (or 2.6m for insulated bodywork)

Maximum height: none in the UK - 4m in most of Europe. The vast majority of trailers in the UK tend to be 4.2m, with Double Decks regularly reaching 4.88 (16').

Lowest floor height at the back (for straight-frame trailers on 1.250mm fifth wheel height) on 385/55 R22.5 is 1.1m above ground.

Lowest floor height at back (for step-frame trailers) on 215/75 R17.5 twins is 870mm above ground.

The use of a Teardrop roof is not limited to the UK - indeed we have a Euro version within 4m and it does show a marked improvement (current analysis shows circa 8% fuel saving). However, this design is now fully patented in Europe.

The one major thing you need to be wary of is the rear design. The trailer width cannot taper inwards too much due to loading and height needs to be kept critically as high as possible. Not good for aerodynamics, but as said elsewhere here, the Kamm effect can be used.

We would be very interested to know more about your work.

Regards

Don-Bur

[skyking]

Don, thanks for posting. The loading dock is the big problem, and making a "transformer" like trailer is the only and non-practical answer that I can see. If you could count on high overhead clearance at the dock or backing to the dock, you could retract a fairing up and over the roof. Unfortunately this is never the case. Can't make it retract to the sides because you are backing the dock with other trucks, etc.
have you looked into a sliding side system that retracts boat tail panels into the respective sides and roof? It would reduce the loading area width a bit but the rest of the trailer would be unmolested.

[DON-BUR]

Originally Posted by skyking

Don, thanks for posting. The loading dock is the big problem, and making a "transformer" like trailer is the only and non-practical answer that I can see. If you could count on high overhead clearance at the dock or backing to the dock, you could retract a fairing up and over the roof. Unfortunately this is never the case. Can't make it retract to the sides because you are backing the dock with other trucks, etc.
have you looked into a sliding side system that retracts boat tail panels into the respective sides and roof? It would reduce the loading area width a bit but the rest of the trailer would be unmolested.

Loading docks are indeed a big problem - especially the load forces induced on the rear-frames when the trailers reverse up and dock up to the buffers.

As you're talking about boat-tails, then this is unfortunately illegal in the UK as the fairing exceeds overall length. The only answer would be to shorten the trailer - but that then reduces load space and becomes unviable.

Tapering is the tempting solution, but again, rear aperture width is critical due to standard width loading ramps that come off the bay into the back to level out the floor (also known as dock levellers). Dock equipment is very expensive and operators will not be willing to start changing all dock levellers to suit "new fangled aero trailers".

The only answer left is to introduce aerodynamic "tricks" at the rear, incorporating diffusers or something else in an attempt to reduce that rear suction pocket.

As yet, we have not seen anything better than our MK2 Teardrop rearframe but are always on the lookout.

[KamperBob]

Richard, the "illustration" pix on your website are interesting to stare at even if they are not computationally or experimentally accurate. I took the liberty of relayering them as an animation to aid comparison.



I had to reduce pixel size due to EM file size limits so the flow lines fringed but it's still fun eye candy. If you'd like the full-scale animation to post on your website I'd be happy to email it directly. Just PM me with you addy.

[DON-BUR]

Many thanks for your efforts.

Unfortunately, my post count is too low to send PM's!!

However, you can have my e-mail address here.

richard.owens@donbur.co.uk

As a matter of interest, is it possible to delay the frames to, say 2 seconds? Or even tween the images so that it fades from one to the other? If not, your current efforts are greatly appreciated.

Regards

Richard

[BamZipPow]

I wonder to retrofit a standard box trailer here in the US...one could use an inflated bag setup? Deflate when yer not using it or need the extra clearance.

[DON-BUR]

I believe this concept has already been done - but with doubts about durability.

It's a great shame we can't use the rear boat-tail in the UK.

Please note - as we do not have enough posts yet, we cannot reply to PM's. Vesa - we are interested but cannot reply for this reason. Have you got an e-mail address?

Regards

Richard

[Vekke]

Then make more comments on various topics . I sended email to your work email...