Solve the following:
Q: A long pyroceram rod of diameter 20 mm is clad with a very thin metallic tube for mechanical protection. The bonding between the rod and the tube has a thermal contact resistance of Rt.c = 0.12 m · K/W.
(a) If the rod is initially at a uniform temperature of 900 K and is suddenly cooled by exposure to an airstream for which T8 = 300 K and h = 100 W/m2 · K, at which time will the centerline reach 600 K?
(b) Cooling may be accelerated by increasing the airspeed and hence the convection coefficient. For values of h = 100, 500, and 1000 W/m2 · K, compute and plot the centerline and surface temperatures of the pyroceram as a function of time for o < t="">< 300="" s.="" comment="" on="" the="" implications="" of="" achieving="" enhanced="" cooling="" solely="" by="" increasing="" h.="">
