ylexot
Super Genius
Ok, I can't figure out the formula. For one thing, the formula in the figure is different from the figure in the text (has T1 and T2 swapped...insignificant really, just affects direction of conductance). And I have no idea why he's using a natural log function. Here's the basic equation for thermal conductivity:
dQ/dt = k * A * dT/x
Where:
dQ/dt is the rate of heat flow
k is the thermal conductivity constant for the material
A is the total cross-sectional area of the conducting surface (this is where his use of pi, length and some of the radii come in)
dT is the difference in surface temperatures
x is the thickness of the material (radii also come into play here)
dQ/dt = k * A * dT/x
Where:
dQ/dt is the rate of heat flow
k is the thermal conductivity constant for the material
A is the total cross-sectional area of the conducting surface (this is where his use of pi, length and some of the radii come in)
dT is the difference in surface temperatures
x is the thickness of the material (radii also come into play here)