EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

This work describes the application of the discrete approximate meshless method with the explicit Euler time scheme for simulating the solidification of a binary alloy with grain motion in a square cavity. The volume-averaged physical model couples mass, momentum, species, and energy transport equations by dividing the flow into the porous region with stationary solid phase and into the slurry region with free motion of the solid grains. The motion of solid grains in the slurry region is coupled with the motion of the liquid phase, and with the pressure and buoyancy of the solid phase. The nucleation of grains is described with the grain population transport equation. On the microscopic scale, the assumption of infinitely fast diffusion is made by using the lever rule model. The coupling between the pressure and the velocity is solved by using the fractional step method. The performance of the method has been previously verified by comparison of the results with the reference results from the literature, based on the stationary solid phase. The influence of the node arrangement density and timestep on macrosegregation evolution and final macrosegregation pattern is analyzed and discussed for the much more computationally involved moving grains physical model.