Impingement cooling

[borjame]

For similar impingement jets acting over similar distances, is there a higher h associated impingement on a flat plate or a plate where each jet hits a raised cone? Is the increase in area due to the cone outweighed by the now oblique angle of the jet relative to the surface? I realize there are more variables, like the size of the cone, it's height relative to s and d, etc., but I'm looking for generalities. If one doesn't always win and the answer is "it depends", I'll take that too.