脈衝流是一種經由改變流體流速，直接影響微型流道的混合效率的方式，不因流體擴散特性而受限制。在本篇論文中，便是以脈衝流的流速變化特性，針對低雷諾數下流體的混合效率結果進行探討。文章中以Y型的微型流道為分析的架構，並於流道之兩入口端，輸入相等頻率且呈180度相位差之脈衝流，藉由以此模擬相同體積流率下，方型脈衝波與三角型脈衝波兩種脈衝流之混合效果。由本文的數值模擬結果來看，輸入較高的頻率及較低的體積流率，均會縮短流體達完全混合的距離；而在相同的頻率和體積流率下，方型脈衝波之完全混合距離約為三角型脈衝波形之1.7倍。最後，針對流道混合效率值和位置關係，進行輸入頻率與平均流速之無因次化分析後，結果呈現了相同波形擁有相當一致的曲線關係，且不隨脈衝輸入的頻率和體積流率所影響。 A pulsing flow is a flow with a frequency-dependent flow velocity which can be used to enhance the mixing efficiency of micro-channels that originally is governed by the flow diffusive mechanism. In this paper, we investigated the utilization of the characteristics of pulsing flows with a varying flow velocity to enhance the flow mixing efficiency at low Reynolds number region. A Y-shaped micro-channel was used. Two pulsing flows having the same flow rate with a 180� phase angle were injected into the two inlets of the channel. A numerical investigation was performed to study the mixing efficiency of the channel with a square and a triangular pulsing flow. The results showed that a high pulsing flow frequency and a low flow rate reduced the mixing length of the channel. Moreover, under the same flow frequency and flow rate, the mixing efficiency of a square-wave flow was almost 1.7 times that of a triangular-wave flow. Finally, a nondimensional analysis was performed to examine the relationship between the mixing efficiency and the position of the flow in the channel. The relationship was nondimensionalized with respect to the flow frequency and the average flow velocity. It was found that a universal curve can be obtained for the mixing efficiency of the channel, regardless of the flow frequency and the flow rate.