-6% to -8% L/100km in Trucks with System Drag Reduction

[ausias]

- System Drag Reduction | www.sdr-sys.com/ing -

I'm wondering if inspired (but not violating worldwide patent) aeroattachment could be done to reduce drag and turbulence on Vans, Light Trucks, nad vertical rear end vehicles.

[ChazInMT]

Hmmmm......

[Otto]

Might help somewhat, perhaps even better with such deflectors on sides, too.

The big question is whether this device works better than other such methods, or wheel fairings, etc..

[jakobnev]

To my layman's eyes, it looks like there is more bending of the stream in the image with the device, bending means acceleration which in turn means a pressure difference. And that, to me, means that the pressure behind the truck is actually lower with the device than without.

Thoughts from the experts?

[Frank Lee]

It reminds me of the deflectors we used to see on station wagons and SUVs that directed air down across the back window to try to keep it from getting so dusty. Those are known to increase drag...

Their image purporting to show the "before and after" flow shows, as expected, the same size trailing wake area on the trailer; while they claim the length of the turbulent zone that trails behind is halved. I'm not sure what to make of that; color me skeptical hippo too.

[skyking]

I see a good marketing job

My friend has seen 4~5 trucks in the last few months of travels with .....wait for it......

FOLDING BOAT TAILS!!

Now that I can see working. He did not snap any pics, but he knows to do so in the future.

[vortex]

See ATDynamics.com. Boattail plates of the sort on a full 13'-6" height dry van trailer typically reduce total vehicle drag 5-10% at highway speeds.

[Diesel_Dave]

Originally Posted by skyking

I see a good marketing job

My friend has seen 4~5 trucks in the last few months of travels with .....wait for it......

FOLDING BOAT TAILS!!

Now that I can see working. He did not snap any pics, but he knows to do so in the future.

My wife and I saw one of those a while back on the interstate. She asked me, "What is that thing on that truck?"

My eyes lit up a little and I eagerly responded, "It helps the aerodynamics, you see..."

She cut me off, "Ok, honey, I can see you're excited, but please stop--that's all I need to know."

[slowmover]

She cut me off, "Ok, honey, I can see you're excited, but please stop--that's all I need to know."


Nothing is quite as illuminating as watching The View on television where eye-rolling and muttered asides teach the female audience how to feel about something which, ipso facto, is more important than what to think about it. Not dissimilar from deprecating name calling on FOX, et. al. But, funnier, somehow.

As with all these aero aids, the problem of acquisition cost is worst. The small or individual owner needs them worst, but is least able to absorb the initial cost. Something like feed-in tariffs in re solar generation would be of help, as we would see a boom of creative activity from home garages, small shops, etc. Mondragon is another lense.

.

[Piwoslaw]

Rear deflector on bus increased drag by 3%. More here:
Air deflectors on trucks/lorries, post #6