COMPARISON BETWEEN TEMPERATURE- AND ENTHALPY-BASED FORMULATIONS FOR THE ENERGY TRANSPORT EQUATION IN SOLIDIFYING MULTI-COMPONENT SYSTEMS

摘要

In solidification problems, due to the non linear relation between enthalpy and temperature, specific numerical algorithms are needed. Two main formulations can be encountered, the first termed "temperature based formulations" where the heat transport equation is solved with the temperature as main variable, and the second "enthalpy based formulations" where the average enthalpy is the main variable. In this paper, these two types of formulation are recalled and compared in two cases: a simple one-dimensional diffusive problem, then a simulation of a VAR ingot casting. In the latter case, the formulations are implemented in the CFD code SOLAR. The good accuracy and high performance, in terms of rate of convergence, of the enthalpy-based formulation are demonstrated. It is therefore suggested that this method represents a fast and accurate alternative to the classical temperature-based formulation for solving many solidification problems.