本研究係利用渦流法模擬兩相噴流場，兩相噴流場為同時擁有兩種不同物質型態之流場，通常為氣相流體與固相粒子，也正是本文所研究的對象。本研究首先驗證模擬之單一相噴流場特性，並發現其結果與實驗一致。接著放入不同粒徑大小之粒子於噴流出口，藉由模擬結果發現粒子與渦流結構之間的運動模式分為兩種，小粒子因為慣性小能被渦流捲入至渦流中心裡；大粒子則因渦流無法提供足夠的向心力讓大粒子跟著渦流旋轉運動，而讓粒子被甩到渦流結構外。隨著雷諾數變小，黏滯性變大，造成黏滯擴散項之影響變大，進而使得粒子較容易擴散到渦流結構中心。而由於放入粒子之初始狀態為靜止，倘若將粒子對流場加入考慮則會造成流場能量的消耗，渦流較無法帶動粒子隨之運動。若在噴流出口施加高頻擾動，會提升流場上游區速度擾動量之成長，但對粒子在流場中的影響並不大。

　This paper simulates the gas-particle two-phase single jet by the vortex method. And we put emphasis on the relation between particles and large-scale coherent structure. First, numerical simulation in the gas phase almost resembles those experiments. Then the two-phase numerical simulation displays that the motion of small particle is closely connected to large-scale vortex dynamics and we could found small particles in the central region of coherent structures. But large particles only appeared around the suburb of coherent structures. And the particles move closer to the central region of coherent structures in the lower Reynolds number. In the other hand, they move closer to the suburb of coherent structures in the higher Reynolds number. If the fluid flow is affected by particles, coherent structures would take particles to move hardly. However, the fluctuation near the outlet of the jet would increase greatly if the jet is forced by a high frequency. But the dispersion of particles in the forced jet is almost the same as in the free jet.

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