Fundamentals of Heat and Mass Transfer – Problem 1.32

A one-dimensional plane wall of thickness 2L=100mm experiences uniform thermal energy generation of q dot=1000 W/m3 and is convectively cooled at x=+/-50mm by an ambient fluid characterized by T infinity=20°C. If the steady-state temperature distribution within the wall is T(x)=a(L2-x2)+b where a=10 °C /m2 and b=30 °C, what is the thermal conductivity of the wall?…

Radioactive wastes are packed in a long, thin-walled cylindrical container. The wastes generate thermal energy nonuniformly according to the relation q = qo [1 – (r/ro)2], where q is the local rate of energy generation per unit volume, qo is a constant, and ro is the radius of the container. Steady-state conditions are maintained by…

The thermal conductivity of a sheet of rigid, extruded insulation is reported to be k = 0.029 W/m·K, the measured temperature difference across a 20mm-thick sheet of the material is T1-T2 =10°C. (a) What is the heat flux through a 2m x 2m sheet of insulation? (b) What is the rate of heat transfer through…

A heat sink also spelled heatsink, is a passive heat exchanger that moves heat generated by an electronic or mechanical device to a fluid medium, typically air or a liquid coolant. This process helps dissipate the heat away from the device, allowing for temperature regulation. Heat sinks are commonly used in computers to cool CPUs,…

What is the thickness required of a masonry wall having thermal conductivity 0.75 W/m K if the heat rate is to be 80% of the heat rate through a composite structural wall having a thermal conductivity of 0.25 W/m K and a thickness of 100 mm? Both walls are subjected to the same surface temperature…