Ok...I have a question about baffles, and the use of them.

The common theory seems to be, as Rodney posted above, to use baffles to direct the air "right at the cylinders". In fact, i've seen many suggest that the baffles should point straight at the "center" of the cylinders. This makes no sense to me.

I've always been under the impression that the purpose of fins or blades on any sort of heat sink/radiator/cylinder/etc was to increase total surface area. The more surface area an object has, the more area there is presented to the cooling air flow, and the more area there is over which heat exchange may occur.

That being the case, don't we want the air directed over the ENTIRE cylinder, NOT just at the center? To over simplify, if i have, say, 10 sqin of surface area that i wish to cool, don't I want air moving over all 10 sqin, and not just over a discreet part of it?

It strikes me, then, that baffles might be appropriate if the air inlets would allow air to bypass the cylinders completely (say, inlets much larger than the face of the cylinder(s)), or perhaps may not expose some parts of the cylinder(s) to air (say, inlets well above or below the exposed face), but should, in such a case, be "aimed" at the top and/or bottom of the cylinder(s), not directly at the middle. In cases where the air inlets are directly in front of the cylinders, and of roughly equal size, it would seem appropriate to leave them as is.

Am I missing some key physics here??