slimjim is the intern at the company for which he works. Be easy on him.

 

I bite my tounge.

Drag forces increase with (nearly) the square of the velocity, not the triple. It's actually a little less if you do not assume a constant drag coefficient. The power required is what triples. Thanks for the correction.

 

[QUOTE=JonBoy]slimjim is the intern at the company for which he works.

 

I'm usually out of it within an hour of starting. About the closest I come to working with anything by Bernoulli is when I'm doing FEA (fluid or structural/static) and even then I really don't have to crunch numbers. It's nice having a program do that for me. Of course, you have to backcheck your work but that's straightforward after the first few times.

 

Thanks, all for your replies. I feel a bit like the man who asked what time it was and was told how to build a watch! Basically, I now understand that air pressure IS greater under our cars at speed than ambient, unless we have done expensive mods to change that. I also understand that the top surfaces on our cars act as "airfoils" like he tops of airplane wings to actually create some upward force. These two working together produce the need for those front "canards" and rear spoilers for high speed competition.

Hey, I learned some new things today. It must be a good day!

Thanks all,
Richard

 

Just know that at normal highways speeds, there really isn't an aero package out there that is functional enough to be worth the money. Aesthetics are another story. Even the 40 year old Porsche 911, a car that is eclipsed only by the VW New Beetle when it comes to imitating airfoils, doesnt automatically extend it's rear spoiler until 75 mph (someone correct me if I am wrong).

Hand-calculations suck. Here's to FEA/CFD