Liquid flows in a particular sequence when it is poured out from an open-top receptacle. Since the sequence is hard to catch by experiment, a numerical simulation was performed in this pouring process with the moving particle semi-implicit (MPS) method. A modified solid-liquid boundary condition was verified and employed with a new definition of static liquid layers. The whole system was discretized by a set of particles and the liquid particles were marked and tracked in the pouring process. The flowing sequence of the liquid can be calculated by restoring the liquid particles back to their initial positions before it is poured. The mass transfer property is found to depend on the position of the rotation axis and the rotation speed, as well as the viscosity of the liquid. The mechanism of the flowing sequence results from a temporal vortex and its motion during the process. The character vortex is generated by the rotation of the container. The results reveal a principle for a versatile pouring process and may contribute to the applications in flowing control in many fields.
