Some aspects to consider in modelling the solidification of a Fe-0.8%wt C alloy

This work characterizes the fluid mechanics, heat transfer and mass transfer during solidification of a binary Fe - 0.8% wt C. alloy. The transformation from a liquid to a solid phase occurs inside a mold that has infinitely thin walls, a rectangular shape and is thermally insulated on all its faces, except on the left side. Two models are used; a classic solidification one and one of 'averaged equations', in which the equations of macroscopic conservation for each phase are obtained by averaging the microscopic equations over a volume of finite control. Three alternative methodologies are evaluated for calculating the solid fraction, considering the averaged equations model in all cases, which are: the lever rule, the Schneider procedure and the phase change fraction. The differential equations of lineal moment, energy and mass transfer are resolved with the SIMPLER algorithm and the method of finite volumes. The system of lineal equations associated with the discrete model is resolved by the line to line scanning technique and the TDMA direct method. There are differences in the results of temperature and velocity distribution, liquid fraction and patterns of macrosegregation, which verifies the importance of the solid fraction calculation (CW)