本文研究目的是以雷射震波蒸發法生成金屬微粒，針對震波流場以及金屬微粒的熱傳與運動現象以數值分析及實驗方法進行研究。
數值方面，首先考慮噴嘴以及噴嘴出口區域的速度與壓力變化，運用流場方程式、氣動方程式以及相關數值方法，以數值分析軟體FLUENT計算分析。在參數分析方面，計算不同噴嘴入口壓力值對於流場的速度與壓力變化的影響。其次運動中的金屬微粒溫度、速度的變化是以自行建立的數學模型進行計算，計算過程中運用了熱傳方程式、動量方程式，並分析可壓縮性流對於金屬微粒溫度與速度的影響，此數值模型可以預測 1μm－150μm的鐵(碳)金屬微粒之凝固行為。
在實驗方面使用不同噴嘴入口壓力的條件下以陰影法觀測流場產生的震波、以Nd-YAG雷射生成金屬微粒以並使用光電二極體量測金屬微粒的飛行速度，經由實驗所獲得的結果再與數值結果進行比對。本文的研究結果可以作為雷射震波蒸發法生成金屬奈米粉末的分析基礎。

The object of this thesis is to study the solidification phenomena of carbon steel particles in laser vaporization with shock wave effects. The problem was solved by numerical simulation and experimental observation.

The aspects of the numerical analysis include the particle velocity, flow pressure and particle temperature in the flow field. Using the computational fluid dynamics (CFD) software, FLUENT, the compressible flow problem with turbulence was solved. With the mathematical models formulating the solidification processes of the particle-gas interactions in flight, the heat transfer problem was solved. Furthermore, the effects of compressible flow on metal particle temperature and velocity were also considered. The proposed model can be used to predict the carbon steel particles in the size range of 1-150μm.

The effects of process parameters on the solidification of carbon-steel particle were investigated, the experiments including the flow visualization by shadowgraph method, the generation of metal particle with Nd-YAG laser and the measurement of particle velocity were proposed to verify the numerical results. This research is a fundamental study for the future research on the generation of nanometer particle with pulsed laser radiation and shock wave interference.

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