Yesterday whilst perusing the internet for aerofoil inspiration I found several simulations of stuff blowing past and over a wing. I thought I bet I could make blender do that. I was up most of the night trying to prove myself right. I spent ages trying to get the smoke simulator to change colour with either speed or acceleration. I wasn’t much bothered which as it was the pretty pattern I was after. I then remembered playing with particles ages ago, I was idly clicking on things to see what happened and I got a colour shift . Not something I was looking for at the time, it came in handy early