COOLING OF OPTICAL-FIBER IN AIDING AND OPPOSING FORCED GAS-FLOW

Convective flows in annular passages with the inner core moving at con stant speed were investigated for conditions applied to the cooling of optical fiber during the draw process. Temperature dependent gas prop erties were fully accounted for in the complete set of conservation eq uations. The geometrical configuration of the model was formulated to reflect experimental conditions previously used : For cooling of the f iber in forced flow. The numerical solution of the conservation equati ons was validated using experimental measurements. The numerical resul ts were used to predict the variation of fiber temperature at the cool ing section exit with respect to relevant draw parameters for aiding a nd opposing flows. A mean temperature for the gas properties was found , that can be used to. predict within 10% the exit fiber temperature u sing constant property modeling; The results presented allow estimatio n of the fiber temperature for a wide rang of operating conditions and cooling section geometries.