The temperature profile becomes
T = -750x + 293
where T is in Kelvin (K), and x is in meter (m). Note that the temperature
profile obtained in this case is not a function of the thermal conductivity
(k). The thermal conductivity will affect the temperature profile if it is
not a constant (i.e., say k = k(x)), or if the problem considered is not at steady-state.
According to Fourier's law of heat conduction, the heat transfer through
the window glass per unit area is given by
q/A = -k dT/dx = -k (-750)
= (0.8)(750)
= 600 W/m2
____________________________
*Note: In general, the heat conduction equation can also be applied to a fluid at rest. However, when the fluid is subject to a large
temperature difference, then convection is induced by the density difference due to the temperature difference (i.e., the buoyancy effect). |