Thats a great idea and I think the construction you've described is
close to what I'd imagined too. I'm not sure the test is equivalent
to the operating environment its intended for though. On climb out,
while the IAS may be 60-70MPH, the prop wash is a much higher speed.
Also, the prop wash is much more turbulent than the clean air on the
front of your wifes car, and that has a dramtic effect on the cooling
capability of that air. As I'd mentioned before, a smooth air flow
tends to build up a layer of warm air along the boundary that impeds
heat flow. Where in the turbulent case "new" cool air keeps coming in
contact with the hot aluminum.

Regards

On climb out Ernest Christley wrote in message .com...
Jay wrote:

You might argue that the heat transfer for that area isn't sufficient,
and I think the analysis needs to be done, but not by a direct
comparison of area from an automobile finned type radiator. The
conditions are just too different to make that meaningful. A bottom
up calculation that includes heat transfer effects of turbulent air,
heat transfer properties of materials (likely Aluminum), waste heat
from engine, etc.

So do it. Take a couple of 2'x2' sheat of .035 aluminum and a few
strips of 3/8" flat aluminum. Lay the flat strips on one piece of sheet
so that it forms sides and an interior maze that the water will have
to flow through. Drill, caulk and rivet it together. Add a spout for
the water to go in and come out with temp probes at each one. Add a
couple of T joints to the plumbing of your wife's car (don't let her
catch you at it) and bolt the thing to the hood in a way that will
shield one side (the one that will be inside the cowl) and also simulate
the AOA of the cowl bottom on climbout.

Drive around a while at 60 to 70mph and then report back here with what
you find out.