A heat conducting rod, 0.30 m long, is made of an aluminum section that is 0.10 m long, and a copper section that is 0.20 m long. Both sections have cross-sectional areas of 0.00040 m2. The aluminum end is maintained at a temperature of 10°C and the copper end is at 170°C. The thermal conductivity of aluminum is 205 W/m • K and of copper is 385 W/m • K. Steady state has been reached, and no heat is lost through the well-insulated sides of the rod. The temperature of the aluminum-copper junction in the rod is closest to

The front window of an automobile has a thickness of 4 mm and is defrosted by the passage of a stream of hot air through the inner surface. The thermal conductivity of glass is around 0.78 W/(m oC). Assume the ambient air temperature is -10°C and the external convection coefficient is 65W/(m2 K). If the hot air blowing to defog the glass internally is at 40 ºC and the internal convection coefficient corresponds to 30 W/(m2 K), the internal surface temperatures will be _____________. However, if the car accelerates and maintains high speed, the external convection coefficient should _____________  [increase or decrease?] and if the condition is maintained long enough the temperature of the inner surface of the glass should _____________  [increase or decrease?].

A furnace of 0.3m by 0.3m by 0.6m inside dimensions is constructed of a material having a thermal conductivity of 0.894 W/m.K. The wall thickness is 10cm. The inner and outer surface temperatures are 600 degree Celcius and 100 degree Celcius respectively. Calculate the heat loss through the furnace wall by using (i) Conduction shape factor. (ii) Thermal resistance.

A 5cm copper plate has a thermal conductivity of 395 ?/m-k is used as a heat sink for a semiconductor. A 1mm layer of thermal paste lies in between the two and it has a thermal conductivity of 10 ? /m-k. Solve for the heat transferred at a 5cmx5cm area if the semiconductor is 80C, while the copper plate has a temperature of 30C since it is exposed to ambient air temperature.

Two approaches used in development of the thermal resistance network in the x-direction for multi-dimensional problems are to assume any plane wall normal to the x-axis to be isothermal and to assume any plane parallel to the x-axis to be adiabatic. True or False True False

Write down the Fourier heat conduction equation and explain the meaning of each term in the equation in units. Find the heat conduction coefficient of a cylindrical material with a diameter of 25mm, a length of 30mm, temperatures of its two surfaces T1 = 40.2oC, T2 = 38.9oC, respectively, and a given thermal power amount of 22.4W.