Class 8 Truck modifications - Page 3 - Fuel Economy, Hypermiling, EcoModding News and Forum

gumby79 · 01-11-2017, 11:09 AM

Vg's havs a local air flow directional dependency(can be as much as90° difference from 1 to the next)tuft testing is needed for proper application. VG will allow steeper change of angle with out loosing attached flow. Consider a 3D Printer to produce in house. (I see a short ROIwith the volume of VG'S needed as well as the capability to produce scale models for testing)
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Are you running Road Trains? Single 53'? Triple 20' ? I assume you have many configurations.
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The Canadian artical is interesting, I am still reading it (120pg).

Hersbird · 01-11-2017, 12:14 PM

This paper shows the vortex generators hurt but they don't look the same as the littles ones I have seen.
https://www.google.com/url?sa=t&sour...Qs3Wg-JJm7lr0w

gumby79 · 01-11-2017, 03:47 PM

Quote:

Originally Posted by Hersbird

This paper shows the vortex generators hurt but they don't look the same as the littles ones I have seen.
https://www.google.com/url?sa=t&sour...Qs3Wg-JJm7lr0w

The VG on top(1"x1"x1/8"x1'-1.5'aluminum angle) have a blunt front and rear (rectangular). There orientation is in the direction of travel. Travel and air flow direction seldom match at the rear especially at corners.

The fronts should be curved from bace up and back. Parallelogram with curved leading and trailing edges. Not like the side VGs.(trapezoid)
This is a poor example with witch to condemn all VGs. Poor fit and finish .In my opinion.

Hersbird · 01-11-2017, 05:50 PM

Quote:

Originally Posted by gumby79

The VG on top(1"x1"x1/8"x1'-1.5'aluminum angle) have a blunt front and rear (rectangular). There orientation is in the direction of travel. Travel and air flow direction seldom match at the rear especially at corners.

The fronts should be curved from bace up and back. Parallelogram with curved leading and trailing edges. Not like the side VGs.(trapezoid)
This is a poor example with witch to condemn all VGs. Poor fit and finish .In my opinion.

They did have to make thier own on the fly but that was because none of the actual makers of the vortex generators for sale at the time wanted to supply their product to be tested in an actual wind tunnel on an actual truck. That sort of raises a red flag to me but it was back in 2006.

seifrob · 01-12-2017, 12:06 PM

I see you have all the scientific links already. There are two links from my bookmarks (i am not affiliated with any of the companies, i just somehow like the product although i have never seen it in reality (central Europe is quite different place for big trucks, than Australia or America)

https://www.youtube.com/watch?v=jc8jUXfQnPM

( homepage)

https://www.youtube.com/watch?v=aGF_UcBdZ5I

(homepage)

-they are probably much more expensive than home-built variant, but its insdustry delivered proven solution with all insurance etc.

freebeard · 01-12-2017, 02:38 PM

Thanks for adding the wheel cover story. I'd thought of it but hadn't added it to the thread.

If we get off vortex generators maybe the OP will come back?

ThermionicScott · 01-12-2017, 03:02 PM

I'm a little skeptical of their "proprietary speed-sensing radar technology" -- seems more like it's held closed by a weak spring that gets defeated by a strong enough wake.

craysus · 01-12-2017, 03:40 PM

We have the moon wheels already under trial.... Results are minimal at best on our current rigs... But that may be due to not enough supporting aero...

The trailers boat tails we can't use in Australia as we go over length by adding it on unfortunately

In relation vortex generators... Most of the vortex strikes seem to be a thing of the past.. With products causing twin closed vortices being used now... Eg airtab is one brand... We have them in use and can notice some mileage saving just when installed on last trailer... But I am still to trial on all the locations on the tractor and between trailer gaps etc... Once I find a decent supplier we will progress.

Other aero like replacement hoods to upgrade old poor aero designs from the manufacturer.. Aero mirrors.. Etc.. Still to be actioned as well.

Parasitic losses to the engine I am also starting to investigate... Things like the mechanically driven fan... And other things need to be rectified.. But it's a big work in progress...

I am also investigating tilting the radiator back with a electric fan behind it to reshape the aero of the front...

We can't use undertrays due to amount of wildlife.. (damn kangaroo's) so I can rule that out as well...

seifrob · 01-12-2017, 04:08 PM

Quote:

Originally Posted by ThermionicScott

I'm a little skeptic of their "proprietary speed-sensing radar technology" -- seems more like it's held closed by a weak spring that gets defeated by a strong enough wake.

You know, it's not exactly lying, its marketing . :-)

(Reality agent: "Calm place close to countryside.", English translation: "Seven miles to the closest grocery store". No one will buy "horse ****s", but "environment friendly, biodegradable fertilizer")

OTOH it is proprietary and speed sensing so it's 66% true. ;-). Their PR did good job.

Quote:

Originally Posted by craysus

We have the moon wheels already under trial.... The trailers boat tails we can't use in Australia as we go over length by adding it on unfortunately

I was under the impression that foldable design had exception and the length restriction doesn't apply. Therefore it opens at speeds over city speed limit.

EDIT: I have checked. They claim they have "EXEMPT from U.S. DOT length restrictions" on their webpage. I know nothing about Australia though. But if it proves worth, maybe you can persuade them to get australian DOT approval too.