Real world fun application -- is this a Prandtl probe?

Forum about flow calculators available on and how to find solution for your fluid flow problem.
Post Reply
Posts: 1
Joined: Fri Apr 06, 2012 7:55 am

Real world fun application -- is this a Prandtl probe?

Post by Hercules40 » Fri Apr 06, 2012 8:30 am

Please look at this site: ... ront-wing/.

It purports to show a system on a modern Formula 1 car where, when a certain aero-device is activated, (DRS - Drag Reduction System), an opening is revealed on either side of the rear wing of the car (like a pitot tube opening) allowing air to force itself through the car, through special ducting that runs the length of the car (approximately 4.7 meters) to the front wing, where it's released, stalling it, essentially taking down-force away from the car, and in this fashion making the car go faster on straights.

In a Formula 1 car (especially on the straights), less down-force, means more speed [Actually, that's true of any car/vehicle really]. But certain systems are banned, such as driver activated systems. This is supposed to be a passive system.

I am a degreed Mechanical/Aerospace Engineer, but as with many of my fellow Engineers, I have ventured into so many other areas professionally, that I haven't done pure calculations like these since I sat down to take my EIT exams. I am trying to figure out if I am approaching this problem correctly, and trying to solve it as this:
Where the Velocity is that of the air flowing over the car ~ 200 KPH. Density is that at sea level.

Am I going about this the right way? I figure about a 10 CM pipe diameter (give or take).

Or should I be doing a pipe flow calculation? Can they really be moving air from the back of the car to the front of the car?

Why am I racking my brains on this? Well, other than a brain teaser, I needed the exercise, it was an excuse for me to join this wonderful forum, which I had noticed a while ago, and my brain needed the help.

Thanks for the help and/or advice you can provide!

Post Reply