摘要
　　本文研究目的是以雷射熔蝕生成奈米鎳微粒，並且針對不同流場特性對於奈米鎳微粒的成核成長現象以數值分析及實驗進行研究並進一步的進行分析與比較。在理論分析方面使用計算流體力學軟體FLUENT計算在真空腔中的流場特性及速度分佈，在奈米微粒成長理論是使用考慮粒子碰撞重熔行為的金屬蒸氣冷凝及單體分子濃度的平衡關係式、成核率方程式以及相關的奈米粒子成長尺寸的計算模型。並使用有限差分法將奈米微粒成長理論中的數學模型離散並撰寫Fortran程式語言以求得生成粒子過程中的粒徑變化，最後將真空腔中計算所得之流場速度分佈代入到奈米微粒成長理論的計算中以瞭解流場特性對於生成粒徑及粒子成長機制的影響。在實驗部份則是採用Q-switch Nd-YAG雷射在真空腔體中對鎳金屬靶材加熱並將生成的金屬蒸氣使用氬氣予以冷凝並使用試片於予以收集並進行掃描式電子顯微鏡(Scanning Electron Microscope)分析。在文中可以得到雷射熔蝕生成奈米鎳微粒時粒徑的變化，並且探討流場特性及不同參數下所造成的影響。在本文中可以提出對於使用雷射熔蝕生成奈米鎳微粒完整的噴流理論分析並以實驗相互印證以作為日後從事生成奈米粒子相關研究的重要依據。

Abstract
　In this study the synthesis of metallic nanoparticles by evaporation is generated by a pulse laser irradiated on a metallic target with a rapid condensation in an inert jet flow condenser. In the simulation analysis of local ablation phenomenon in gas plume, which was induced by laser ablation, small particles with narrow distributions were expected in the experiment. The over-heated vapor may become the plasma and it will affect the particle generation significantly. This study is going to apply the computational fluid dynamics(CFD), numerical analysis to simulate the condensation process of the metallic particles under laser irradiating, in order to understand the formation mechanism of the nanoparticles for broader applications to the mass production. The flow analysis is used to investigate the process design in macroscopic and microscopic views respectively to predict the flow characteristics in the laser ablation and condensation for nanoparticle formation.

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