本文探討正方形流域內之位勢流動，二點漩渦以週期交替方式置入流場藉以攪拌流體，兩攪拌子位置與轉動模式，影響攪拌效果甚大。本文採用流體延展之平均概念來鑑別流體攪拌程度，並繪製一些時間線，藉以瞭解攪拌詳細過程。計算結果顯示：當二點漩渦置入位置靠近流場中心、轉動方向相反、以長週期攪動流體時，將增強流體攪拌效果。

This study addressed a potential flow within a square domain. A pair of point vortices was alternatively and periodically inserted into a flow to stir a fluid. Various locations and rotary modes of two stirrers substantially influenced fluid stirrings. The average fluid stretch was used as a tool to distinguish the degrees of fluid stirring, and timelines were plotted to identify the details of the fluid-stirrings process. Computations revealed that fluid stirrings was enhanced under several conditions. The point vortices were located near the center of the flow field, and were counter-rotated or inserted alternatively into the fluid for longer periods.