(Solved): An electron tube with steel casing is shown in figure.5-28. The thermal conductivity, mean diameter, ...

An electron tube with steel casing is shown in figure.5-28. The thermal conductivity, mean diameter, length and thickness of the tube are k,D,L,and ? respectively. The heat transfer coefficient is h, and the ambient temperature is T_?. When the filament is heated we assume that the inner surface of the tube is suddenly subjected to a net radiant heat flux q". Fine the unsteady temperature of the tube. Assume a thin wall tube.