"Bill Daniels" bildan@comcast-dot-net wrote

I've seen cylindrical "barrel" type heat exchangers intended for
installation in a round duct. I wonder if these might be an alternative
choice to the flat automotive-type radiators.


Doubtful that you could get enough surface area in a round radiator. If you
just made it longer, efficiency would suffer, since the half that is
downstream would only be getting hot air.

Dan is absolutely correct, about the ducting and baffles being important.
In the P-51 (probably the best cooling design ever) the duct intake was
small, then the important part was the shape as the duct got bigger, to slow
the speed the air went through the radiator, and also like he said, gain a
little pressure.
--
Jim in NC