Don't get me wrong, this can totally work. You'll just have to change the contour of where the windshield meets the hood, and get rid of the windshield wiper panel, and re-contour the back edge of the hood so the air exits in the correct direction and merges with the laminar flow across the hood. Easy.

You're going to make me quote myself, aren't you...


Let's recap. There is a stagnant flow area at the base of the windshield, where the wipers are. The deeper that area gets (or the faster the airflow over that area), the more stagnant that becomes, and a turbulent area forms. When you raise the back edge of the hood, you're making that area deeper, and more turbulent. How well do you think air exits from beneath the hood right into an area of turbulent flow? Air moves according to pressure, and if you can't make the area under the hood (at that back edge) lower pressure than than the air over it, it's not going to work. Like I said, you can make it work, you just can't expect it to work unless the rest of that area is designed for that. You'd actually do better cutting holes in the windshield wiper cowl panel than you would raising the hood edge.

 

There is no comparison between the two. Air in the bed of a pickup truck travels in a loop off the roof because there is no air coming from under the cab into the bed. It is blocked by the front of the bed and the cab. Air can travel under the hood and on top of the hood where it will simply merge as it exits the rear of the hood.

 

Well put but the edge of the hood isn't shaped in a way that it would make the air turn around far enough or quick enough to push any air back under the hood or keep any air under the the hood. It would have to be a larger curved shape(think of a rock in the middle of a stream, bigger the rock, more turbulent the area behind it. The smaller rocks have little to no effect.) . The air is going to force itself out as it has air traveling behind it and pushing it. I agree there will be a slight turbulence because of the wipers but that won't effect the hot air from escaping.

 

You're trying to compare the surface energy and boundary layer effects of water with air, which is not a good thing to do on something of the size we're talking about.
You don't need a special shape to make the air turn around, it wants to do that on it's own when flowing over such an abrupt change in contour. That's why I was saying that you could make the cowl-cooling concept work if you designed the hood and wiper cowl area specifically to do that.

If you're getting better cooling through raising the hood edge, it's because air is getting drawn in at that point and exiting through the bottom of the car, not exiting at the hood edge I'd imagine.
I'm just very, very skeptical that you could make a large enough pressure difference in that area to get air to exit out of there. It should work great at low speeds and at stoplights though, like I said before.

 

Ok then, think of a really big river. Many science labs that study aerodynamics using scaled down models of vehicles put in moving water and use dies to see what is happening. And shape does matter, its one of the most important parts. It directly effects how the air moves when hits. The change in contour doesn't effect the air flow because the air flow on top of the hood is matched by the airflow under it.

This one is being used for aircraft.
http://iar-ira.nrc-cnrc.gc.ca/aero/aero_8f_e.html

 

hahaha....

 

I dont know why people even bother to argue with Fabrik8

 

wow.................ignorance is truly bliss.

 

I would rather have a forward facing scoop feeding directly into the intake, but based on his setup it made sense to how it works from looking at it.

Maybe I can find a picture and you can say weather or not it would be worth it and/or functional

 

Forgot about this... Rain falls down. It does not travel over the car then turn and land on the rear as if it were going sideways.If it did then again the whole river thing. The back of the car is a much larger area than the rear of your hood. Air traveling under the car goes up and meets in the middle of the back of your car with the air/water which is being pushed down the rear of your car.