NACA duct to vent front wheel wells????? - Fuel Economy, Hypermiling, EcoModding News and Forum

IsaacCarlson · 09-20-2009, 07:26 PM

maybe something like this?

chuckm · 09-20-2009, 08:04 PM

I dunno. At the very least, I think that that is the wrong place to vent. You'll be tripping the air flow coming down the car. I'm guessing, but if you could duct the air into an already turbulent stream, it would probably be better.

IsaacCarlson · 09-20-2009, 09:07 PM

HAHAHA You know that might just work.......

Bicycle Bob · 09-20-2009, 09:14 PM

The sharp edges of the NACA duct are carefully shaped to work as a low-drag inlet. With flow in the other direction, they are quite inappropriate.

robertwb70 · 09-21-2009, 12:24 AM

Bob's right, I checked into using NACA ducts like that a few weeks ago and found out they don't work "backwards".

stevet47 · 09-21-2009, 09:57 AM

Really? I have just been looking into them recently, and although I have only found 1 or 2 sources on using them 'backwards' as outlets, I haven't found anything that says you can't.

robertwb70 · 09-21-2009, 11:47 AM

Here's one thread I saw- Reverse NACA duct [Archive] - AviationBanter
and another- Studying aero: NACA scoops in hood? [Archive] - MX-5 Miata Forum

there are more but it seems fairly obvious to me that NACA ducts are directional so like anything that's directional they would function best in the direction intended.

Try driving your car backwards on the interstate, or hammering a nail with the handle of the hammer, or gnipyt sdrawkcab no ruoy draobyek...you get the idea.

moorecomp · 09-21-2009, 12:07 PM

The best outlet is one which will allow the exiting airflow to be as close as possible to the direction of the external airflow. In other words, the exit air should be as close as possible to parallel to the direction of travel. It would seem the "backwards" NACA vent would provide a good direction for airflow, but the way it would be causing the air the constrict in the reducing width slot would induce turculence into the exit airflow. A similar design of just a simple rectangle would seem to be better..

dcb · 09-21-2009, 12:17 PM

Quote:

Originally Posted by moorecomp

A similar design of just a simple rectangle would seem to be better..

perhaps
McKinney Corp. Race Cars - Naca & Outlet Ducts
an outlet among naca inlets

IsaacCarlson · 09-21-2009, 01:08 PM

Would this make the flow smoother? or would i be better off with that outlet vent? Or maybe push brooms...
[ATTACH]The right way? HEHEHE[/ATTACH]