Measurement and prediction of thermocouple probe temperatures within glass rods subjected to radiative heating

Existing data from thermocouple probes inserted into fused silica glass rods within an optical fiber draw tower furnace were used for comparisons with modeling predictions. Radiative transport model through the glass was based on the zonal method and a four band model with two absorbing and two non-absorbing bands. The glass rod and thermocouple probe temperature distributions were computed as a coupled conduction-radiation problem within the furnace enclosure. Predicted and measured results were in good agreement in spite to limitations imposed by incomplete knowledge of relevant glass properties and the assumption disuse glass surfaces.