Tugas 1

1.      A hot fluid enters a concentric-pipe apparatus at a temperature of 300°F and is to be cooled to 200°F by a cold  fluid entering at 100°F and heated to 150°F. Shall they be directed in parralel flow or counter flow?

 2.     If 3 kW is conducted through a section of insulating material 0.6 m2 in cross section and 2.5 cm thick and the thermal conductivity may be taken as 0.2 W/moC, compute the temperature difference across the material.

 3.     Water flows at the rate of 0.5 kg/s in a 2.5-cm-diameter tube having a length of 3 m. A constant heat flux is imposed at the tube wall so that the tube wall temperature is 40◦C higher than the water temperature. Calculate the heat transfer and estimate the temperature rise in the water. The water is pressurized so that boiling cannot occur.