Random Wind Tunnel and Smoke Pictures Thread

[kach22i]

There is something reassuring and comforting about wind tunnel and smoke pictures, at least for me.

Post them if you have them.

Mercedes-Benz-Blog: The new Mercedes-Benz E-Class Cabriolet - TecDay Aerodynamic 2009 - PART X


Dodge - 2010 Ram 1500 - Design - Best In Class Aerodynamics


100 Year-Old Aerodynamics Problem Solved: Could Increase MPG Dramatically
By Ovidiu Sandru ..............September 27, 2008
100 Year-Old Aerodynamics Problem Solved: Could Increase MPG Dramatically - The Green Optimistic

MIT researchers discovered the solution to a problem put 100 years ago by Ludwig Prandtl. It refers to the situation when, for example, a car accelerates up and down a hill, then slows to follow a turn, and the airflow around it cannot keep up and separates from it. This aerodynamic phenomena creates an additional drag, slowing the car, and forcing you to push harder on the pedal, consuming more gas. The same applies to airplanes, boats, subs, and generally, any moving object following the rule mentioned above.

Around 50 images in this thread alone:
Car Wind Tunnel Data

[Cd]

Fantastic idea ! I hope this gets pinned.

By the way, that Dodge has the smoke PhotoShopped in. ( They wish it looked that good ! )

It is much closer to this Ford :

[spacemanspif]

A2WT HomePage. They are a wind tunnel that anyone can use (assuming you are willing to pay for the time) to test their cars. Many pictures and vids on their websites. Most cars aren't small eco-boxes like our but you can watch the videos and see how things really help or hurt aero.

[bondo]

Nice tunnel with a great crew. In the picture below is Dave Salazar the General Manager. He is an Aero Engineer and he has forgotten more than I will ever know. They have two tunnels there, the smaller A2 tunnel (which I could afford) and a much larger tunnel NASCAR uses adjacent to it which gets pricy quick.

One problem with wind tunnel testing a large vehicle in a wind tunnel with a small cross section, is that the final Cd number may be skewed due to the compression of the air between the walls of the constricted test chamber and the large frontal area of a vehicle like a full size truck. Best to test a small car in the A2.

It is fun to watch the smoke though!

Bondo

[kach22i]

Originally Posted by spacemanspif

A2WT HomePage.

Interesting video.

Got me to wondering about that VW wind tunnel with a rotating turntable base to simulate crosswinds. When I have the time I'll post something on that.

RE: Photoshop Dodge truck smoke.

They fooled me, I hate when that happens. Proves once again that you cannot trust everything you see on the Internet.

Random pictures, like the thread title says:

http://www.a2wt.com/Pictures.htm

[Cd]

kach22i : Would it be all right with you if we also post tuft tests here as well ?

Unless you really know what to look for, I'm guessing most of us can't see turbulence with smoke testing as easily as you can with tuft testing.

With tuft tests, you can literally see the pockets of air that are causing problems and the direction of the airflow.

[Cd]

Turbulence !

[Cd]

By looking at the smoke stream, it looks as if the wind speed here is moving at a crawl.

I think GM doesn't wan't to show how bad that the drag is on the new Camaro. And note that this only shows the roofline. I'd like to see them test near that open grille.
Aero disaster !

[Cd]

[Cd]