利用分子動力學模擬白金平板內的熱傳效應

• Main Author: 林繼于
• Other Authors: 許文震
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/75426517888341848835

碩士 === 國立清華大學 === 動力機械工程學系 === 93 === The Langevin model frequently provides a numerical method to simulate the dynamic of liquid or gaseous molecules over an isothermal plate. In the present study, we utilize the Langevin model to investigate the validity of Fourier’s law for the temperature distribution of a platinum plate with a thickness is of nanometers. When temperatures on the top and bottom of plate are identical, the results show that the temperature distribution inside the plate is entirely uniform with a maximum uncertainty of 10% for the thickness of 2 ~ 3 nm. This approach is also applied to the conditions of two sides of the plate at different temperatures. When the thickness of the plate is smaller than 16 nm, the temperature distribution in the most part of plate is isothermal. The temperature jump is observed on both edges of the plate. Obviously, the Fourier’s law is not valid for the thickness below 16 nm. The results also reveal that the Langevin model is a good temperature controlling tool. As the plate thickness is increased to 100 nm, a constant gradient of temperature distribution inside the plate is obtained; thereby the Fourier’s law is applicable.