Boussinesq approximation to compute the temperature and velocity distributions in glass melts

Abstract

The objective of the paper is to discuss the basis of glass melt modelling. For the governing equations to compute the Joule heat, temperatures and velocities in glass melts, conditions and criteria have been derived which enable the use of simplified equations and material properties. The computed examples base on the properties of the typical mass glasses: float glass, green container glass, fibre glass (E-glass) and Pyrex-type borosilicate glass. The computations show that in future it will be necessary to get more knowledge about the cubic and temperature-dependent expansion coefficient of glass melts. The per volume element constant viscosity, thermal and electric conductivity cause inaccuracies of more than 5 % in numerical modelling. The proposal is made to name a similarity number of direct Joule heat production Staněk number.