("Ron Garret" wrote)
Not quite. They have to reach thermal equilibrium if there is no heat
flowing in or out of the system. But, as you correctly note, heat can
(and doe) flow in and out via radiation. Surfaces can "soak up" the
cold of the night sky (actually, they radiate their heat into the night
sky) and become colder than the surrounding air, just as they can "soak
up" the heat of the sun and become warmer than the surrounding air.
Eventually some of the cold/heat does get transferred to the air. This
is why clear nights tend to be colder than cloudy ones (and why clear
days tend to be warmer, all else being equal).


So on the 41F night in question, and having imaginary temp probes build into
the composite wing surface, we might see overnight wing temperature readings
of say 29F or 30F?

Is there a way to (WAG), in advance, what different surface temps will be on
the night in question? (41F overnight and 40F at 8:15 am)

Knowing air temp, humidity, cloud cover, wind, etc - could someone predict
that the composite wing will be in the 25F - 31F range overnight, whereas
the aluminum wing might only get briefly down to say 35F? Aluminum being
willing to give up its heat to the air more readily than the composites?


Montblack