Thermal Behavior of Optical Fibers during the Cooling Stage of the Drawing Process

摘要

Thermal behavior of optical fibers during the cooling stage of the drawing processudhas been studied numerically. An optical fiber during the cooling stage of theuddrawing process can be modeled as an infinite cylinder moving in still air at audconstant speed. Two-dimensional unsteady energy equation is solved using fourthudorder Rungue-Kutta method (RK-4) for time integration and second order finiteuddifference schemes for spatial derivatives. Two-dimensional steady boundary layerudequations are solved to estimate the value of convective heat transfer coefficient atudthe surface of the fiber using implicit finite difference method. The velocity andudtemperature contours are plotted with different values of Reynolds number. Theudvalue of convective heat transfer coefficient is matching very well with the resultsudavailable from the literature. Results are reported with different speed and size ofudthe optical fiber. Reported results show that the cooling rate of the optical fiber isudincreases with the increase of drawing velocity at a fixed diameter. The cooling rateudof the optical fiber is increases with the increase of diameter at a constant drawingudvelocity. The cooling rate of the optical fiber decreases with the increase of thermaludconductivity for a fixed size and drawing speed of the fiber. The present results areudmatching very well with results available from the literature.