Numerical simulations on fibre fabrication

The controlled heating of the fibre preform to temperatures of around 2000 °C is a crucial step during fibre fabrication. The geometry of the oven and the corresponding 3D temperature profile determine the viscosity of the hot glass and the geometry of the neck-down region. In general, fibre drawing ovens are rather complex and consist of many different components (heating elements, insulator, water cooling system etc.) and materials (graphite, stainless steel, Argon, water etc.). Thus, computing and optimising the internal 3D temperature profile requires a detailed modelling combined with state-of-the-art numerical thermal analysis, e.g. based on finite volume approaches. Thus, such thermal simulations are very time-consuming and require sophisticated hardware resources. This is undesired in the context of large-scale parameter studies, which could be used for optimisation. Consequently, we are working on concepts of simplifying the modelling as much as possible, e.g. by condensing the model to only few but relevant elements and by applying appropriate boundary conditions. At the end of this on-going process we hope to have an easy-to-use and time-efficient modelling tool that allows us to study and optimise the fibre draw process in all relevant details.

The results were partly obtained by Poorna Sai Rayalacheruvu as part of his Master's thesis.