A nickel-coated heater element with a thickness of 15 mm and a thermal conductivity of 50W/m · K is exposed to saturated water at atmospheric pressure. A thermocouple is attached to the back surface, which is well insulated. Measurements at a particular operating condition yield an electrical power dissipation in the heater element of 6.950 x 107 W/m3 and a temperature of To = 266.4°C.
(a) From the foregoing data, calculate the surface temperature, Ts, and the heat flux at the exposed surface.
(b) Using the surface heat flux determined in part (a), estimate the surface temperature by applying an appropriate boiling correlation.