Fundamentals of Heat and Mass Transfer – Problem 1.32

Abstract The purpose of this lab was to determine the thermal conductivity k of the disk material by measuring the temperature distribution for transient and steady-state heat conduction in a cylindrical wall. To conduct this experiment cooling water was pumped though the HT10X Heat Transfer service Unit at approximately 1.5 liters/min. Initially the heating power…

A furnace for processing semiconductor materials is formed by a silicon carbide chamber that is zone-heated on the top section and cooled on the lower section. With the elevator in the lowest position, a robot arm inserts the silicon wafer on the mounting pins. In a production operation, the wafer is rapidly moved toward the…

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…

Assume steady-state, one-dimensional heat conduction through the symmetric shape shown. Assuming that there is no internal heat generation, derive an expression for the thermal conductivity k(x) for these conditions: A(x) = (1 – x), T(x) = 300(1 – 2x – x3), and q = 6000 W, where A is in square meters, T in kelvins,…

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…

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…