Re: heat gain problem

In article <5cs98lF31n5s9U1@xxxxxxxxxxxxxxxxxx>,
Michael Dahms <michael.dahms@xxxxxxx> wrote:

Jeffrey J Weimer wrote:

This is not a materials property question.

Take peaces of wood, aluminum and steel. Heat them to 100 °C, then touch
them! You'll feel the difference.

Hmmm ....

My apologies. I think I see now.

Assuming all materials have the same temperature, which "feels" hotter
and why? I was focusing on the fact that some materials get hotter than
others under the same conditions.

Is a useful analogy, that cooking oil at 100 oC will cause a greater
burn than water at 100 oC?

In this case, since touching the surface initiates a non-steady state
heat transfer, it seems that thermal conductivity and thermal capacity
both come into play.

In other words, how hot something "feels" (when at a given temperature)
is not just dependent on the rate of heat transfer out of the material
(through its thermal conductivity k), it is also dependent on the amount
of heat available within a given mass of material (through its density
rho and specific heat capacity Cp).

Isn't this the thermal diffusivity (k / rho Cp)?

--
JJW
.

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