[Dieselguru]

The company I worked for was the industrial arm of a huge automotive/on-highway cooling system company, so we took as much as we could from the truck guys. So yes, we used aluminum tube and fin (normal automotive) construction and also another construction called bar and plate used mostly for air to water CAC's, military coolers and high pressure applications.

I found a simulation I did using a 1.5" deep core with a 12 fin per inch louvered fin. You get ~175 Pa pressure drop at 4.5 m/s air velocity. With a 1.25" you get ~175 Pa with 5 m/s air velocity.

Thats about all I can't really answer your question about face velocity because I never looked at it. Most of our applications were either stationary or didn't move fast enough for ram air, we were always concerned about mass flow and core pressure drop (yes, related to velocity, but we never looked at that number). You were given a space claim and heat rejection target and the challenge was to find a fan that could move the required mass flow through the cooler(s). We also used mostly non-louvered fins (louvered is all they use in the automotive world) to prevent clogging and reduced pressure drop with extremely deep coolers (4 inch deep core was tiny).

I know some manufactures will give you some data on their coolers. As an FSAE team they would sometimes provide a rough datasheet on the cooler performance.

Sorry I couldn't help more