Flow Illustrator - a simple windtunnel simulator

[Sean T.]

where are you guys getting these bitmaps of your cars?

[azraelswrd]

We make our own bitmaps. Find an image, pop it into some image editing program and delete non-car (but make sure to preserve the ground level to simulate the tires height).

I've done my xA (haven't posted it) and was working on that Prius.

[azraelswrd]

2008 Prius

YouTube - Prius 2008 flow sim

Re = 2465148 (calculated for 55mph)
dt = 0.01
length = 30sec
cutoff level = 0

[extragoode]

One thing I'm noticing on these that they're going to be pretty inaccurate if you don't have a belly pan, since all your bitmaps have smooth bottoms.

[cfg83]

extragoode -

Originally Posted by extragoode

One thing I'm noticing on these that they're going to be pretty inaccurate if you don't have a belly pan, since all your bitmaps have smooth bottoms.

I did an approximation with some random "bumps" on the underside and didn't see much of a difference. I'll upload it later tonight so you can see.

CarloSW2

[donee]

Hi azrael...,

Ooops..

[donee]

Hi azrael...,

Thanks for the Prius model.

The flow off the top, and off the bottom look very balanced. Possibly there is more flow coming up from below, and going turbulent. My car always has a dirty rear window undeneath the hatch spoiler. That seems to support the model results. Possibly a linear difusser, and a shallow angle might help that.

The car has very poor flow out the wheel well vents. And the hatch fogs up easily, and takes along time to defog. So, this also supports that the flow from underneath the car is stalling.

[ebacherville]

here is the areo CRX as it sits in its current state..

http://www.youtube.com/watch?v=x9_uKixh9i8

[skyl4rk]

So other than being interesting in a lava lamp sort of way, how do you interpret the video to determine what is a lower air resistance?

Less red is better?

Less movement (wave action) is better?

Both?

[ebacherville]

Im not positive but yes i think your right less red and less wavey the better