本文研究在低速氣流條件下使用旋流噴嘴，進行雷射材料蝕刻並分析加工後表面品質。針對旋流衝擊平板，以數值分析及實驗方法進行分析。在數值分析方面，建立物理模型及假設，導入連續、動量、紊流方程式及顆粒運動方程式，以FLUENT軟體進行計算，討論不同切線入口速度旋流衝擊平板所形成的壓力分佈、速度場及顆粒運動路徑。在實驗方面分為旋流噴嘴流場觀測與平板壓力量測，由壓力量測的結果確認工件表面的壓力分佈情形，並比較數值計算與實驗結果。最後進行雷射蝕刻加工實驗，利用顯微放大並擷取加工表面影像，從得到的照片及表面粗度量測加以比較並說明結果。本文可作為旋流噴嘴應用於雷射加工之基礎研究。

The effects of the gas streams on removing the plume in the laser ablation were studied experimentally and numerically in this thesis.

In the numerical analysis, the swirling flow was impinging to a substrate during the laser ablation. Using the computational fluid dynamics (CFD) software, FLUENT, the continuity, momentum, energy and turbulent, particle momentum equations was solved for the swirling flow problem. The numerical results show the pressure fields of swirling flow impinging on the substrate, field of velocity and path of particle tracing at various tangent velocities. The flow characteristics were confirmed with the flow visualization in the experiments. The pressure fields of the swirling flow on the substrate was also measured and calculated. The results show that the distribution of the gas velocity on the substrate was significantly affected by swirl strength, which was used to remove the plume in the laser ablation. Finally the surface roughnesses of the grooves were measured. It is a fundamental study for laser ablation process with swirling nozzle in the future.

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