Random Aerodynamic Oddity of the Day Thread

[freebeard]

https://s-media-cache-ak0.pinimg.com/736x/82/06/c0/8206c0d6a82d4cab8ee4291976dea6f7.jpg

Cross-current performance? Else, no idea.

[kach22i]

Originally Posted by freebeard

Cross-current performance? Else, no idea.

The delay of vortex generation, not sure if it worked as intended.

Alfa Romeo BAT (see Bat-5)
https://en.wikipedia.org/wiki/Alfa_Romeo_BAT

The BAT 5 was the first of the Bertone-Alfa Romeo BAT project. It was first shown at the Turin Auto show in 1953. The design of the model was based on a study of aerodynamics. The shape of the front in fact aims to eliminate the problem of airflow disruption at high speeds. The design also aims to do away with any extra resistance generated by the wheels turning, as well as achieving a structure which would create the fewest possible air vortices.

Not too shabby.

The car had a drag coefficient of 0,23.[4]

[samwichse]

2018 Toyota Camry has ducts for flow separation under the rear tail lights.

[Piwoslaw]

Originally Posted by kach22i

I found something odd, and if all "fluid dynamics" are fair game then explain the advantage of the gap/slot before the movable portion of the rudder.

My 2 guesses:

1. To increase the flow over the movable part. This may slightly increase drag, but improves the efficiency of the rudder, allowing it to be smaller. And a smaller rudder reduces drag and/or noise.
2. When the movable part turns to one side, there will be lower pressure on the "back" side, causing additional noise. The gap allows this void to partially fill in, reducing noise.

For a submarine silence is more important than fuel efficiency.

[Frank Lee]

[freebeard]

Just A Car Guy: IH land speed racing big rig, the Neighbours Nightmare. 1950 IH model R190 that's went 151mph, purpose built to race on the salt flats at Lake Gairdner, currently powered by a Twin Turbo Detroit 12v71

[aerohead]

Originally Posted by kach22i

I found something odd, and if all "fluid dynamics" are fair game then explain the advantage of the gap/slot before the movable portion of the rudder.

MORE random pics...... - Page 4443 - Pelican Parts Technical BBS


I have an idea or two but want to see if it matches anyone else's ideas.

My guess is,that it's about the 'acoustic' signature of the boat,which an electronics officer aboard an 'enemy' vessel might pick up as an anomaly, when dived.
At zero-yaw of the rudder,the water coming to it would be 'clean',as well as the water coming off it.
A common 'slot' between the two might generate more 'noise.' Potentially 'deadly.'

[freebeard]

Not really aerodynamic and not really an oddity, I just wanted to point to the 4-door hardtop station wagon, a body style that last only 3-4 years:



Just A Car Guy: Buick Caballero

I don't know that I've ever seen a Cabellaro. It's distinctly different to the Chevy Nomad/Pontiac Safari 2-doors.

Bonus: an Art Deco wagon:



Just A Car Guy: 1949 American Metalcraft streamlined Autowagon (Thanks Robert!)

[kach22i]

Originally Posted by freebeard

Not really aerodynamic and not really an oddity, I just wanted to point to the 4-door hardtop station wagon, a body style that last only 3-4 years:

Not sure what you mean, almost all station wagons are (were) four door.

I'd like to see a side by side comparison of a wind tunnel test using old wrap-a-round windshields compared to the later ones that followed with a more sloped inclination angle but sharper corner edges.

I bet it would be a near wash or equal.

From the wind tunnel test videos I've seen almost no air goes directly over the car, most of it angles off the hood and windshield and slides off near the rear view mirror location. This would make the windshield radii at the corners most important.

That little red wagon reminds me of this.

https://www.pelicanparts.com/swapmee...gekuhltgallery



Sort of an aero-oddity of a trailer too.

Wish I had a side profile view.

EDIT: while looking up something completely different I found another view.

http://flatsixes.com/cars/porsche-35...ler-rod-emory/

[kach22i]

Maybe not so unusual, but I've never seen such a complex one.

Something interesting... Cabriolet Wind Deflector - Pelican Parts Technical BBS