本論文利用相場法(Phase-field method)，及二相流(Two-phase flow)模擬金屬表面受一集中熱源加熱熔融後之暫態熱流行為。流場以二維暫態模型，考量質量方程式、動量方程式、能量方程式以及等位函數，以求得包含流體交接面的溫度、速度、壓力及等位數整體分佈。過程忽略流場因濃度的擴散影響，而考慮溫度熱傳，結果顯示溫度造成熔區與周圍空氣之浮力流動、溫度梯度所產生的熱毛細力所驅動的熔區流動。

This study uses the Phase-field method to simulate the transient thermal current of the metal surface heated and molten by a massing energy. The flow field uses a two-dimension module, considered with the mass conservation equation, momentum equation, energy equation and level-set equation, to solve for the distribution in whole domain, including
the interface, of temperature, velocity, pressure and level-set number. We ignore the effect of concentration diffusion, but consider about the effect
of heat translation on the flow field. Finally the results will display the flows of air around molten area forced by buoyancy which is caused by high temperature, and the flows in molten area forced by thermocapillary
which is caused by temperature gradient.

目錄 I

圖目錄 II

符號說明 III

中文摘要 VII

英文摘要 VIII

第一章　緒論 1
　　　1.1 研究背景 1
　　　1.2 二相流與相場法(Phase-field method) 1
　　　1.3 研究目的與簡介 3
第二章　理論分析與模型設定 4
2.1 模型統御方程式 4
(A). 質量守恆與等位方程式 4
(B). 動量方程式 5
(C). 能量方程式 7
　　　2.2 模型域設定 8
(A).模型幾何、邊界與網格設定 8
(B).各流體性質設定 10
第三章　模擬結果與討論 11
3.1 模擬條件與說明 11
3.2 模擬結果 12
3.3 結果討論 20
第四章　總結 21
參考文獻 22

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