Simulation of channel segregation using a two-phase columnar solidification model - Part II: Mechanism and parameter study

► Formation mechanism of the channel segregation. ► Onset of channel segregation by the flow perturbation. ► Growth and stabilization of the channels are due to flow-solidification interaction. ► Remelting is not a necessary condition for channel segregates. ► Rayleigh number is a reasonable indicator for the formation of channel segregation.