Y型微混合器内流流场移动粒子半隐式法数值分析

The flow field of a Y-type active micromixer with an impeller and two inlets is numerically simulated using moving the particle semi-implicit method, in which the fully developed velocity inlet model and the moving boundary model are combined. A high efficiency inclined continuous inlet model based on position judgment is proposed. A local mixing rate calculation method, which can describe ideal ordered mixing, is defined, and the key parameters of this method are determined through numerical experiments. Simulation of the flow field shows that for the continuous mixing of two immiscible liquids, the mixing mainly happens in the counter current region of the chamber. The mixing index at the outlet channel fluctuates periodically due to the multiple effects of continuous inflow, rotation of blade, and geometry of this mixer. This paper reveals the mixing mechanism and the transportation process in a steady-state period, and studies the influences of inlet velocity and rotating speed on mixing index. It is found that the mixing index can be improved by properly reducing the inlet flow rate or increasing the rotating speed, but the mixing degree will decrease if the inlet flow rate is too small.