Steady-state Heat Conduction in Planar Walls: Screencast
Shows how to write a thermal circuit for a composite wall with two different materials in series and parallel.
We suggest that after watching this screencast, you list the important points as a way to increase retention.
Important Equations:
For a composite wall with no heat generation:
The equation for heat flux is:
\[ q=\frac{T_0\, -\, T_4}{R_{total}}\]
where \(T_0\) = temperature of the left side of the left wall
\(T_4\) = temperature on the right side of the right wall
\(R_{total}\) = total resistance to heat transfer
\[R_{total} = \sum_{i=1}^{4} \frac{x_i}{k_i}\]
where \(x_i\) = thickness of each wall segment (cm)
\(k_i\) = thermal conductivity of the wall’s material (W/[cm K])
The wall temperatures can be calculated from left to right according to:
\[T_i = T_{i-1}\, -\, qR_i = T_{i-1}\, -\, q\frac{x_i}{k_i}\]
where \(R_i\) = thermal resistance
\(T_i\) = temperature