Water Tunnel Flow Visualizations
 

This didn't quite fit in the experiments section... not really related to FE. And it's not exactly an aerodynamic modification :P But for the interested, we were given permission to fire up the water tunnel at my university last year for flow visualization. Here's some of the things we put in there.

https://www.primitiveengineering.com/...nnel/apple.jpg

https://www.primitiveengineering.com/...l/cylinder.jpg

https://www.primitiveengineering.com/...l/golfball.jpg

https://www.primitiveengineering.com/...nnel/nerf1.jpg

https://www.primitiveengineering.com/...nnel/nerf2.jpg
Slight upward angle caused the flow to spiral around.

https://www.primitiveengineering.com/...el/porsche.jpg

https://www.primitiveengineering.com/...l/porsche2.jpg

https://www.primitiveengineering.com/...l/porsche3.jpg

https://www.primitiveengineering.com/...nel/shield.jpg
Interesting Pressure Wave Form

https://www.primitiveengineering.com/...el/shuttle.jpg
Now that is awesome flow attachment :P


I also have some short video clips taken by my camera... I'm waiting for Google to finish processing them. So I guess tomorrow I'll link them :D

Very cool. All we need now is little models of all the GS members' vehicles!

Actually Mattel does make a boat load of "regular" cars as diecast models. Just pu in your make and model of car in the search field of Ebay and then put diecast behind it. I'm still debating whether or not I want to shell out $15 for a diecast of my 94 hatch since it was a rare one.

Close enough
 

For the Element, this penny racer should be close enough. :-)
https://www.tyborg.com/media/choroQ.jpg

I have yet to find any model version of my Geo Metro, yet I have a '74 Ford Pinto :D:

Attachment 333

I should've bought the AMC Gremlin when I saw it too.

Cool stuff. Did you calculate equivalent "real life" speeds for what you saw for the flow rate & model sizes?

Not sure but water doesn't compress as air does so you don't get a true flow model by using water. Interesting flow patterns on the under carriage flow coming out of the rear wheel wells.

You're 100% right that it won't compress - however, at low speeds (that is, sub transonic) water will act like air with respect to high pressure stagnation and high pressure "bubbles" (note apple photo).

That being said -- this tunnel moves pretty slow. Using equivalent Reynolds numbers for water--> air, the "air" flow is a tad over 3mph... Scaled for those 1/64th cars - that's less than .05mph :( So that tunnel really isn't a good way to find separation points on scaled object - but separation aside, you get a pretty good idea of where things are moving....

Nasa's is Much Better :)

I used to dream of building one of these in my room haha, but decided the lack of compressability would make it not so worth while?

Cheep wind tunnell - Park in an alley on a windy day and start a fire in front of your vehicle and watch how the smoke flows around your car. ha ha ha just don't start too big of a fire!!