A CFD Model to Simulate Thermal Mould-Filling and Solid-Liquid Phase Change During Aluminothermic Welding of Rails

The present work introduces a model to simulate the flow field inside the mould and predict the solid-liquid phase change during the mould-filling stage of the aluminothermic welding process. The volume of fluid method has been used to model the steel-air multiphase system, and the enthalpy-porosity technique has been adopted to predict the phase change. The multiphase model has been implemented in OpenFOAM®, a finite volume method based computational fluid dynamics program. The \(k - \varepsilon \) turbulence model has been extended to account for the phase change during the mould-filling stage. The numerical results enable a detailed understanding of the flow field and the shape of the melted rail profile within the mould after the completion of the mould-filling stage. Moreover, the predictions of the melted rail profiles within the mould are compared with those from the experiment, and a reasonable agreement has been observed.