Random Aerodynamic Oddity of the Day Thread

[freebeard]

Lowers pressure under the car...
Decreases pressure behind the radiator,

Part can be installed either way. They apparently blow out through the front wheels. Morelli's FIAT had rear wheels that suck through the wheels and exhaust into the tires wake.

Completely dependent on the porosity of the wheel.

[j-c-c]

Originally Posted by kach22i

Brake cooling?

https://forums.pelicanparts.com/off-...-pics-864.html


EDIT:

Looks to be a thing....................................

https://www.facebook.com/groups/2950...6603867905030/

Another example.

Ultra Cool ALUMINUM Brake Fans Small 5 Brake Fan (5/8 stud)
https://www.circletracksupply.com/ul...fs5-625x1.html



https://www.youtube.com/embed/y8t1RUWof4I

I am not sold. Only truly positive aspects I am convinced of are they are better at is lining the pockets of the seller, and give the driver the perception his brakes are now being cooled.

The downsides omitted from this discussion so far:
a. They increase unsprung weight, albeit slightly
b. they consume rotational energy
c. I submit they cool an entire caliper less effectively then current design of ducted encapsulated caliper shrouds
e. they exhaust more air thru the wheel's exterior disrupting already contentious wheel air flow around the car's body, but wonder if when at speed there is an "air curtain" effect blocking wheel exhaust airflow
d. they move air mainly on one side of a flat rotor vs the most effective cooling surface of a vented rotor, the interior finned surfaces
f. Not sure if one stipulates the fans remove hot air, and conversely that hot air is now also 'cooling" the wheel/tire somehow
g. Their design is somewhat inefficient, in that they mainly "beat" the air, as there is no real clean air supply path for cool intake air for this crude centrifugal fan.
h. Brake blowers/ducts are cooling brakes/calipers at car speeds from 0 and up, these "fans" not so much

[Piwoslaw]

IIRC there has been discussion here of wheel rims which would "pump" air outwards, reducing pressure under the car.
The reduced pressure would have to fight the suspension springs, and the outcome of the discussion seemed to be that the increased pumping losses outweighed any benefit from potentially reduced underside aero drag and/or temporary lowering of the car (assuming the suspension gave in).

Given this outcome, these rotor/fans might lean towards the unaerodymic thread.

Anyway, these do not work well with smooth moonies, so, yeah.

[freebeard]

Here is something I wonder about: The Armstrong Whitworth AW.15 Atalanta, the first British four-engined monoplane passenger aircraft, had an evolution of the landing gear from a full wheel pant to this curious cycle fender.

http://airwar.ru/image/idop/cw1/aw15/aw15-c1.jpg

What purpose does it serve. It won't contain ground spray, it's too high to shield the top of the tire.

The only comparison that comes to mind is the Tropfenwagen, with it's surfboard shaped fender mounted to the body.

[j-c-c]

Rocks piercing internal wing tanks?

[j-c-c]

Originally Posted by Piwoslaw

IIRC there has been discussion here of wheel rims which would "pump" air outwards, reducing pressure under the car.
The reduced pressure would have to fight the suspension springs, and the outcome of the discussion seemed to be that the increased pumping losses outweighed any benefit from potentially reduced underside aero drag and/or temporary lowering of the car (assuming the suspension gave in).

Given this outcome, these rotor/fans might lean towards the unaerodymic thread.

Anyway, these do not work well with smooth moonies, so, yeah.

Since items you noted were primarily on fronts, any ground effects were likely only an afterthought.

[cRiPpLe_rOoStEr]

Originally Posted by j-c-c

Rocks piercing internal wing tanks?

That's an interesting point, since most runways at that time were unimproved.

[Piotrsko]

If it's fabric wing: stuff gets all goofy bad REALLY fast when you poke rocks onto or through your fabric covered wing. You do have to double stitch a fabric wing at the fuselage. Otoh, Gas tank just dents, would have to be a really large sharp pointy rock to poke a hole even in 1/16 aluminum sheet, even back then fuel was carried in "tern" steel tanks

[ennored]

Don't know if this belongs here, maybe in the unaerodynamic thread, as I can't find anything but some marketing hype about it being "aerodynamic". But I'll start here.

Thoughts? Maybe someone has some numbers? It's so damn ugly, the least they could have done is make it have some decent aero, right?



Oh yeah, it's an Oshkosh NGDV (new mail truck).

My apologies if it's been mentioned here, did a quick search and found nothing...

[freebeard]

Thoughts? ... It's so damn ugly...

Beauty is in the eye of the beholder - Phrasefinder
In Molly Bawn, 1878, there's the line "Beauty is in the eye of the beholder", which is the earliest citation that I can find in print. The 1980s saw the coining of the term 'beer goggles' (the increased attractiveness of the opposite sex when one is drunk)

It's the pug nose. It appears the intent is more windshield, less hood.

Compare the top edge bevel with the Kanoo or Robovan. They could've extended it down into a three-piece windshield. That bumped hood is something aerohead tested on his T-100 at Bonneville. It didn't seem to help.