Random UnAerodynamic Cars and Trucks Thread

[kach22i]

Random TRANSPORTATION pictures - Page 1573 - Pelican Parts Technical BBS



Just some more variety.

[redpoint5]

I have seen a few of these in the wild. What is the Cd of a brick again?

[jamesqf]

Originally Posted by freebeard

A 0.21 Cd SUV might be a stretch limo with a fineness ratio of 2.78:1 or whatever.

Sure, but I guess you missed the point I was trying to make, which is that the best possible aerodynamics won't compensate for too big a cross section.

As for the tractors &c, what point to aerodynamics when your top speed is maybe 10 mph?

[arcosine]

Originally Posted by Cd

How about that one ?

I'd love to see this disaster in a windtunnel.

Yes it needs a 460ci engine just to go 55 mph.

[kach22i]

Originally Posted by redpoint5

What is the Cd of a brick again?

I tried looking that up yesterday because the same question popped into my head. I didn't come up with much, but this morning I looked at this page.

https://en.wikipedia.org/wiki/Drag_coefficient


A brick is not listed, but a cube is, and a long cylinder is.

I'm going to guess somewhere near 1.0 is the Cd of a brick.

EDIT: Found some other stuff, not so sold on some of it's accuracy.

The drag coefficient of a brick is typically 2.1. The drag coefficient of an upright person is anywhere between 1.0 and 1.3.

http://www.kgbanswers.com/what-is-th...brick/22219529
Read more http://www.kgbanswers.com/what-is-th...#ixzz3mevdXHWe

I remember posting information on "Blunt Bodies" in the forum a few years ago, some of them with close proximity to the ground.

EDIT-2: FYI - I think bricks are called square cylinders.

Got that from here:
http://www.sciencedirect.com/science...17931011004327

And got that from the thread I remembered:
http://ecomodder.com/forum/showthrea...y-11592-8.html

EDIT-3:

http://www.calqlata.com/proddetail.asp?prod=00021

Long Prism (face): Calculates the shape coefficients of a long rectangular beam with the fluid flowing at right-angles to the axis of the beam against a flat face

There ya go, just over 1.0 as projected/assumed earlier.

I should note that proximity to the ground is a pretty big factor not to be ignored.

[kach22i]

MORE random pics...... - Page 3619 - Pelican Parts Technical BBS

Alerted by the smell of a broken bottle of liquor, Federal Agents inspect a "lumber truck." Los Angeles, 1926

[freebeard]

Originally Posted by jamesqf

As for the tractors &c, what point to aerodynamics when your top speed is maybe 10 mph?

Three words "art deco toaster"

It appears from the Wikipedia chart that the brick does better in a 45° cross-wind.

[cRiPpLe_rOoStEr]

Originally Posted by kach22i

.41 to .42 isn't all impressive for this VW (better than the Z's near .48), and I assume it has a more or less flat floor pan too. I'll admit that a bit perplexed by some of this.

T3 Aerodynamics



Vw Sp2 1974 Azul/Blue
Vw Sp2 1974 Azul - Ano 1974 - 94000 km - no MercadoLivre


MORE random pics...... - Page 3619 - Pelican Parts Technical BBS

The SP2 is weird with its square front-end in contrast to its smooth rear end. Have you ever seen one live? I still see some once in a while.

[kach22i]

Originally Posted by cRiPpLe_rOoStEr

The SP2 is weird with its square front-end in contrast to its smooth rear end. Have you ever seen one live? I still see some once in a while.

I'm not sure if I have, I'm getting old in the head.

I did see a cousin of it in 2011, the Puma.

http://ecomodder.com/forum/showthrea...e-27014-3.html

[Cd]

Nice and sleek, until the air get trapped in that area behind the cab !

This one doesn't count - it's not street legal :



I've been unsuccessful at finding a picture of a city maintenance truck with their signage up, but I know we have all seen them.
It's a giant flat sign on the bed of the truck that rotates. It has a flashing arrow to alert motorist of construction ahead.
Unfortunately, I see plenty of these trucks driving along with the sign still up, versus folded down.