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Old 11-21-2020, 12:47 PM   #11 (permalink)
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Quote:
Originally Posted by M_a_t_t View Post
What video/car? It sounds like a mod I was thinking about trying.
Found it ! : https://youtu.be/PcQGu5N8tTc

At the 4:21 mark

EDIT : I'm also adding this interesting link here, so as not to clutter this thread up :
https://gmauthority.com/blog/2019/04...-aerodynamics/


Last edited by Cd; 11-21-2020 at 01:03 PM..
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Old 11-21-2020, 02:55 PM   #12 (permalink)
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https://youtu.be/PcQGu5N8tTc?t=262

I'd call those fences rather than strakes. The GM Authority example is curved and at an angle to nominal air flow.
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Old 11-21-2020, 03:47 PM   #13 (permalink)
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Quote:
Originally Posted by freebeard View Post
https://youtu.be/PcQGu5N8tTc?t=262

I'd call those fences rather than strakes. The GM Authority example is curved and at an angle to nominal air flow.
Yes. FENCES would be the correct word.

Here are two examples I mentioned earlier, as seen on jets .
The jets being an Su-22, and an F-14 .

I was amazed the first time I did a tuft test on my 93 Civic. The car has prominently raised rain gutters alongside the windshield.
I thought for sure these would act as fences, and direct airflow upwards to the roof, but the air just skips right over them, and apparently without tripping into turbulence.

Oh and yes, I too was puzzled at the curved strakes.
And quite a steep curve as well.
I would have thought for sure such a thing would have just tripped up the airflow.
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Old 11-22-2020, 10:50 AM   #14 (permalink)
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Just out of curiosity, I added this side shield to see if i could direct airflow away from the mirror, as it spills around the windshield.
I even planned to take video, but everything flopped.
From the test, there was massive turbulence behind the mirror.
I also noticed the tufts just behind the mirror pointed straight up right as I began driving. This was evident at perhaps less than 10 mph.

In the photo, you can see how the piece has bowed outward. I installed it straight.

So what do you all think is happening ? Is air actually spilling over this shield and creating a massive vortex ?

I did some CFD that seemed to verify that even with a huge side shield, the air just spills right over the sides as if it's not even there.

Would it be worth it to do further testing on this ?
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Old 11-22-2020, 11:47 AM   #15 (permalink)
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I would assume that it is blocking that flow around the windshield creating a sort of wake effect. Maybe the pointed up tuft is because the side airflow is now looking for a different path, maybe towards the (I assume) low-er pressure on the roof/ top of windshield area?

Is it worth testing? Entirely up to you. If its creating a wake then maybe not in its current version.
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Old 11-22-2020, 11:51 AM   #16 (permalink)
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Were you thinking a scaled up version of this? This is the newest honda fit btw
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Last edited by M_a_t_t; 11-23-2020 at 12:31 AM..
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Old 11-22-2020, 12:13 PM   #17 (permalink)
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I'm pretty sure that would suck problematically when driving in snow. I wonder about the Fit.
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Old 11-22-2020, 01:01 PM   #18 (permalink)
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Quote:
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I'm pretty sure that would suck problematically when driving in snow. I wonder about the Fit.
You think snow would collect there?
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Old 11-22-2020, 01:56 PM   #19 (permalink)
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My 1958 VW Beetle convertible collected snow on it's flat windshield, a problem I don't remember in a Beetle sedan. Something about the square upper corners.
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Old 11-22-2020, 03:28 PM   #20 (permalink)
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All my bugs collected snow on the windshield, I think it's a function of defrost strength

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