Turbulator - Verringerung des Luftwiderstandes | Posts 16+

09-02-2009, 13:36 Subject:

jarobaldu wrote:

The word itself, "laminar separation bubble," indicates the phenomenon: after 1 meter of hood length, there is no longer laminar flow. Therefore, there are no separation bubbles in that area.

Turbulent flow can also detach if the pressure gradient increases too rapidly; it is somewhat more tolerant of this than laminar flow. No airflow can follow the sharp angle at the rear of a station wagon or other vehicle with a steeply angled rear end.

jarobaldu wrote:

After a few years of experimentation, I believe the following approach is worthwhile: First, simply measure. If you get positive results, then it's worth considering "why?"

It's still better to avoid completely pointless measurements. Measurements are too time-consuming to blindly check every conceivable scenario.

09-02-2009, 21:26 Subject:

Guys,

"Der Hucho" is a great book. It's going straight onto my wish list.
Thanks to Uni-Bib, I'm just browsing through and looking at the pictures for now.

I probably won't have time to read until I retire.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

11-02-2009, 10:56 Subject:

christians wrote:

Turbulent flow can also detach if the pressure gradient increases too rapidly; it is somewhat more tolerant of this than laminar flow. No airflow can follow the sharp angle at the rear of a station wagon or other vehicle with a steeply angled rear end.

That's why the rear also gets a deflector spoiler; a vortex generator wouldn't be effective there.

christians wrote:

It's still better to avoid completely pointless measurements. Measurements are too time-consuming to blindly check all conceivable configurations.

And how else would you disprove such "inventions"?
I still believe that a simple approach with or without [something] is the best solution.

11-02-2009, 11:15 Subject:

Would you measure whether a sheet spread behind the stern reduces fuel consumption?

Some things can be calculated, or experience tells you that there's no need to measure any further.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

11-02-2009, 12:25 Subject:

Hi there,

before anyone here thinks that I believe in the Turbultor...

There's a lot of misleading information out there claiming to save fuel, but proper measurements can prove that it doesn't work. Some automotive magazines have already written about this.
I would suggest using the exact same approach for these "turbulators."

And I'm almost certain that the inventor would still find arguments as to why the measurement was unsuitable: the air pressure was too high, the color of the car was inappropriate, and the lunar phase was wrong...

Regards,
Adrian.

P.S. What color should the bed sheet be?

11-02-2009, 12:41 Subject:

White and red, so that it is clearly visible when I throw it away towards the end of the measurement and it sticks to the windshield of the car in front

.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

11-02-2009, 22:28 Subject:

*loud laugh* What a completely nonsensical thing to attach to the roof

. If someone forgets to remove it before driving into their (underground) garage, it will cause more harm than good! It's unbelievable that people still fall for this...

13-02-2009, 16:11 Subject:

After doing some extensive online searching, I've found a few more interesting links:

http://www.prova.de/archiv/2003/00-artikel/0073-citroen-c-airlounge/index.shtml
http://www.saubereautos.at/fortschritt/diesel/renault_macht_dacia_eco2tauglich/
http://www.mitsubishi-motors.com/corporate/about_us/technology/review/e/pdf/2004/16E_03.pdf

The study in the link you provided states that the drag coefficient (Cw) could be reduced by 0.006 on the Mitsubishi. However, I couldn't find a statement specifying whether this new Cw value refers to the original frontal area or the newly created (larger) one.

13-02-2009, 17:11 Subject:

After a quick glance, I believe that in the last link, the large rear wing and its airflow are more related to the vortex generator than simply reducing drag (cw).

It seems that it's not getting enough flow when the VG is missing.

Furthermore, they conducted their measurements at 180 km/h... the Peugeot from the "aforementioned inventor" cannot achieve that speed

.
And if so, the "Turbolator" has "imprinted" itself on the windshield of the vehicle behind.

m;

Read the Hucho!!!

13-02-2009, 18:09 Subject:

dieselmartin wrote:

Furthermore, they made their measurements at 180 km/h... the Peugeot from the "aforementioned inventor" cannot achieve that speed

.

17-02-2009, 17:42 Subject:

Here's the ultra-short version of the 1000-page Hucho book.

http://media.automobilrevue.ch/files/93612_luftwiderstand.pdf

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

18-02-2009, 13:54 Subject:

Again: On a car with a steeply sloping rear end, like the one in question, this effect wouldn't be noticeable. Also, even the rear window of a sedan would be too steep. If the car didn't have a limited width, vortices would form at the C-pillars, which would reduce or shift the stall point.