Deturbulator tape

[Bman83GL]

Hi folks,

I was doing a review at the SAE site to see what aerodynamic papers I need to catch up on when I ran across this.

Looks like it is still in the developmental stage.

http://www.sinhatech.com/

Bman

[2TonJellyBean]

Wow, a 30% reduction in aero drag by running a strip of "turbolator" tape across the roof above where the front seat passengers sit? How simple is that?

I must give this genius inventor money!!! LMAO

An interesting find though...

[trebuchet03]

I'm ALWAYS wary of aero flow add ons to a semi truck that claim high numbers -- there's not a great deal you can do to the flow that's already on a semi given the extremely high Reynolds number....

Look at that! bring the cD of a van from .5 to .1! Not sure how he validated scale wind tunnel testing - it's very dependent on physical length...

[2TonJellyBean]

The only scientific portion is quantifying how wild the claim can be before it starts tripping even the gullibles' BS meters.

[lunarhighway]

i've come across something similar on the web. turbulator tape seems to be comonly used on gliders and is somewhat similar to vortex generators, although not entirely.

the way i understand these things work is that they're placed just ahead of a sepparation bubble wich is a point where laminar flow seppatates from the wing. the additional drag they cause is smaller than the drag the bubble would cause.
for the turbulator to function this point has to be exactly determined.

there might be potential for this on cars, but the very exact placement and potential to small to measure gains might might make this difficult for most people to implement.

on the other hand this turbulator tape seems to be nothing else than a thick sawtooth patterend tape, so people willing to try might be able to make it themselves. or use the stuff used on gliders if you have access to it.... afterall if you compare the width of your car's rooftop to the span of a glider youd only need a small leftover.

[8307c4]

Just use duct tape, what's the difference?

[ChrstphrR]

Originally Posted by 8307c4

Just use duct tape, what's the difference?

Hunting around a little:

Seems to be that traditional glider turbulator tapes are raised vinyl sawtooth tape -- with different lengths/frequencies of the sawtooth pattern.

Sinha's turbulator tape looks to be more like a sandwich -- imagine duct tape with a thin plastic set of stand-offs.

1) Bottom layer's the adhesive portion to stick it to the vehicle / airfoil surface.

2) Then there's the "ridged substrate", a set of (equally spaced) standoffs above the adhesive layer.

3) Atop the ridges is a thin membrane -- probably made of mylar, or since the examples are sort of shiny... aluminum backed mylar?

The height of the tape, top to bottom, according to the diagrams he's used in his SAE presentations, is only 50 to 100 micrometres (2 to 4 thousandths of an inch). Erm, I don't think it's much thicker than duct tape would be, really. Sounds a lot more like coroplast scaled down, with saran-wrap on top instead of the hard plastic sheet the one side.

Instead of presenting a "rough" surface, like the sawtooth tapes, or say, sandpaper grit-side-up, the design Sinha's testing seems to vibrate the membrane on top to perturb airflow and/or dampen and remove energy from turbulant flows to make them more calm and laminar, instead of strong, rolling eddies.

[Hateful]

Originally Posted by 8307c4

Just use duct tape, what's the difference?

I've got plenty of duck tape on my car but I'm not going to place any on a surface that is already a smooth curved surface, but to deflect air from going under the car and into the wheel wells.
Looks like yet another gimmick to me.

[Dynamically Aero]

In the photo of the Escalade model in the wind tunnel (click on the photo for a larger image) we can see the deturbulator strip across the front of the roof just aft of the windshield. Do you think the tape going across the hood to secure the model has any measureable effect on the aero?

We've seen photos of vortex generators on the sides of vehicles; might deturbulator strips be beneficial there, too? If so, where on the sides do you think would be most effective?

[cfg83]

Hello -

I found this on the site :

Improving Automotive Fuel Efficiency with DeturbulatorTape
SAE Paper: 2007-01-3458
SAE 21st Asia Pacific Automotive Technology Conference, Hollywood, CA, U.S.A.
5th-8th August, 2007
http://www.sinhatech.com/SAE-APAC-20...08-06-2007.pdf

I can't make heads or tails of it. When I went to look at the specific conference event guide, I couldn't find the Sinha paper (EDIT: Found it, see next post) :

“Impacts & Opportunities for the Global Automotive Industry”
http://www.sae.org/events/sales/brochures/APAC.pdf

Here is the organization that is was presented at (maybe) :

14th Asia Pacific Automotive Engineering Conference (APAC-14)
August 5-8, 2007 / Renaissance Hollywood Hotel / Hollywood, California, USA
http://www.sae.org/events/apac/

While the name has changed to reflect a broader audience, the 14th Asia Pacific Automotive Engineering Conference still embodies what the original International Pacific Conference on Automotive Engineering (IPC) stood for. A successful, historic event since 1981, APAC serves as a way to promote automotive engineering development worldwide, choosing this year's theme, "Impacts & Opportunities for the Global Automotive Industry," to focus on five major technology subjects:

* Powertrain Technology
* Driver/Vehicle Interface, Information and Assistance Systems
* Vehicle Design and Manufacturing
* Transportation Challenges in Emerging Markets
* Vehicle Dynamics and Intelligent Control Systems

SAE is pleased to host this premier automotive engineering event with patronage by FISITA.

Here are other events :

http://www.sae.org/events/conferences/groundvehicle/

2007

DoD Maintenance Symposium & Exhibition
November 13-16, 2007, Rosen Shingle Creek Hotel, Orlando, Florida, USA

SAE 2007 Automotive Dynamics and Safety Conference and Exhibition
November 27-29, 2007, Doubletree Hotel Dearborn, Detroit, Michigan, USA
Event Canceled

SAE Brasil Noise and Vibration Conference - NVH
November 28-30, 2007, Florianópolis/SC, Brazil

Congresso SAE Brasil
November 28-30, 2007, Transamerica Expo Center, São Paulo, Brazil
Prospectus*

Here is something interesting. There is a conrference in Anaheim on December 2-5 2007 :

EVS-23: Sustainability - The Future of Transportation
December 2-5, 2007, Anaheim, California, USA
(SAE International co-sponsoring industry affiliate)
http://www.electricdrive.org/evs23/


CarloSW2