determining thermal properties?

Question

I need to know the thermal conductivity, diffusivity, and emmisivity for stainless steel clad copper. I don't know if thickness matters but this has a thicker copper interior (~.90cm thick) clad with a small amount of stainless steel to equal a total thickness of 1cm (0.01m).

I have the following values for stainless steel:
Thermal Conductivity k = 14.9 W/m * C
Thermal Diffusivity (alpha) = 3.68 x 10^(-6) m^2/s
Emmisivity (epsilon) = 0.58

I have the following values for copper:
Thermal Conductivity k = 401 W/m * C
Thermal Diffusivity (alpha) = 97.1 x 10^(-6) m^2/s
Emmisivity (epsilon) = 0.90


I appreciate your help.

Answer 1

For the emmisivity you would have to use the value for stainless steel since that is the surface exposed to the outside of the cable.
For conductivity and diffusivity you could picture it as a piece if insulated copper with the stainless being the insulation.
The heat has to pass thru the stainless steel to get to the copper, and then thru the copper and then out thru the stainless steel. Multiply each conductivity and diffusivity value by its length or thickness, then add them together and divide by the total length to get the average.