Will these strakes cause more drag ?

[Cd]

Originally Posted by M_a_t_t

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/

[freebeard]

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.

[Cd]

Originally Posted by freebeard

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.

[Cd]

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 ?

[M_a_t_t]

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.

[M_a_t_t]

Were you thinking a scaled up version of this? This is the newest honda fit btw

[freebeard]

I'm pretty sure that would suck problematically when driving in snow. I wonder about the Fit.

[M_a_t_t]

Originally Posted by freebeard

I'm pretty sure that would suck problematically when driving in snow. I wonder about the Fit.

You think snow would collect there?

[freebeard]

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.

[Piotrsko]

All my bugs collected snow on the windshield, I think it's a function of defrost strength