GTijoejoe

iTrader: (25)

I am going to confirm (parts of) his statement
(besides "convection...in our case heat, through contact", not really sure where that one was going, probably a statement getting combobbled or misunderstood)

As stated the louvers are there for the support of ambient coming air. While static the heat will dissipate regardless from HOT->COLD. Quick compressible areodynamics lesson: As the ambient flow hits the base of the louver it will form contractions waves, as it flows over the top of the louvars it will form expansion waves creating a low pressure. The low pressure will aid in pulling the heat out of the engine bay. Of course if you watched the louvers in a wind tunnel I would expect the first set to be the most important in directing the airflow (from ambient air).

In addition the louvers will support the ambient airflow not to
a) Rush in the engine bay (this can vary depending on air speed)
b) trap the hot air in your engine bay from trying to escape efficiently
As your vehicle plows through the static (assuming no wind conditions) air it will slightly compress and try to move out of the way (remember we are subsonic here, the air "knows" you're coming), but it will form a boundary layer over the nose of your vehicle's body begining to flow its contour. If there is a hole in your hood the flow will try to do a) of b) to my knowledge.

Did I design Mits louvers?- no
Have I done any testing to prove my theoretic input?- no
I actually design brakes for an OEM, but I do have an AE and ME degree

PHDoc19

iTrader: (9)

Pardon my mistake. The energy transfer term I was looking for was "conduction," in which one media removes energy from another where it is in greater density than the first, in our case heat from the engine. I was going strictly on memory, and it's been a few years since my undergrad, which was in chem and not physics. I did make A's in physics though, fun stuff. My grad degrees have forced me to stray from true lab science and concentrate more on health science, but I still love it just the same.

One other point that you bring up that I did not consider is the density of air outside the engine bay vs inside the engine bay. Air rushing over the car will be more dense and less energy saturated. Sorry, I will just use the word "heat." Air that has made contact with a hot engine on the other hand will of course be heat saturated and less dense, and based on air movements due to gradients would, at least in my mind, suggest the heated air would rise and be expelled by the cooler air rushing over the top of the vent.

I think this only strengthens the idea that the louvers do have a functional purpose. Going back to the idea of unidirectional air movement, the louvers provide a physical barrier that prevents air rushing over the hood from entering the vent, going inside the engine bay, hitting the firewall, cycling under the car, or whatever it would do at this point. In any case, air is coming in when it should be going out. Heat would be trapped for longer in the engine bay as air of lower density is now creating a wall that the heated air must penetrate in order to escape.

Any other ideas?

Evolved Monkey

iTrader: (1)

I think the argument for keeping the vent cover on is that the fins create a low pressure area behind it when there is airflow over it (i.e. car in motion) that hot air from the engine can get sucked out. Without the cover, airflow over the hood act like a gate to keep hot air in similar to how airgates in stores keep their air conditioner cooled air in without closing the door.

BoostinMR

My concern:

The heat shield causes my BOV to push my hood up when closed, and I need the space. With that being said, the holes in the shield were engineered for a specific reason. Size, shape, location etc... I am wondering if removing it will cause airflow volume/direction issues? (Looking for technical answer please)

BoostinMR

Should have read previous posts, please disregard.