AN ANALYTICAL METHOD FOR DETERMINING THERMAL-CONDUCTIVITY FROM DYNAMIC EXPERIMENTS

The temperature profile along a cylindrical rod or tube as it cools ha s been obtained by numerical solution of the second-order time-depende nt partial differential equation for heat conduction. The surface temp erature is calculated for given temperature dependent values of the he at capacity, hemispherical total emissivity, thermal expansion and the rmal conductivity and, by adjusting the thermal conductivity, is fitte d to experimental temperature profiles obtained from preliminary measu rements on a cooling cylindrical tungsten rod. The surface temperature of the rod is quite sensitive to the thermal conductivity but the acc uracy of the predicted thermal conductivity cannot be assessed without further experimentation.