Simulation of heat transfer and phase interface during melting process of floating-zone crystal-growth

• Main Authors: Lin, Tang-yu, 林殿裕
• Other Authors: Chen Jyh-chen
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/23309883345223198881

碩士 === 國立中央大學 === 機械工程學系 === 84 === Numerical simulation was carried out to study the melting process of LHPG system under no pull rate. A high Prandtl number material (i.e. LiNbO3) was considered. At different reduction ratio, unknown shapes of the melting region, and the steady- state, symmetric flow and temperature fields were solved using a finite difference method, employing with boundary-fitted curvilinear coordinate system. It is observed that the two-cell flow structure in the melt for LiNbO3. When reduction ratio is less than 1, the flow of up region was stronger than that of low region under small power; melt-solid shape bugles inward, and the melt-gas shape bugles outward. At big power, the flow field of the low region was stronger than that of the up region, the melt-solid shape bugles inward, but the melt-gas necks. When reduction ratio was greater than 1, whether the power is small or big, the flow of up region was stronger than that of the low region, and the melt-solid bugles inward, and the melt-gas bugles outward. Although the Marangoni number decreases with the increase of the input power, the instability of the thermocapillary flow may not appear. The present results agree very well with the experimental results.