Fundamentals of Heat and Mass Transfer – Problem 2.10

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…

An electric resistance heater is embedded in a long cylinder of diameter 30mm. When water with a temperature of 25degree C and velocity of 1 m/s flows crosswise over the cylinder, the power per unit length required to maintain the surface at a uniform temperature of 90degreeC is 28kW/m. When air is also at 25…

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…

A square isothermal chip is of width w = 5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated, while the front surface is exposed to the flow of a coolant at T infinity = I5 degree C. From reliability considerations, the chip temperature…

An array of 10 silicon chips, each of length L=10 mm on a side, is insulated on one surface and cooled on the opposite surface by atmospheric air in parallel flow with T∞​=24°C and u∞​=40m/s. When in use, the same electrical power is dissipated in each chip, maintaining a uniform heat flux over the entire cooled surface….