本研究主要以非平衡態分子動力學模擬方法(NEMD)，探討具分支構造奈米碳管的熱傳行為。本文首先介紹分子動力學的基礎理論與非平衡態分子動力學模擬法(NEMD)的原理與機制。在建立模型時，以熱焊的方式去接合十字型與T 型接頭(Cross- and T-junction)，為了探討原子組態對熱流的影響，本研究將各別建立兩個不同型態的十字型與T 型接頭。模擬結果發現，T型奈米碳管的熱比較容易往前傳，而十字奈米碳管則比較容易往側傳，不同的原子組態也會有相同的趨勢。本研究觀察T型與十字形奈米碳管在低溫時的熱流結果，發現在T型奈米碳管中，熱更容易往前傳，而在十字型奈米碳管中，熱更容易往側傳。T型與十字形奈米碳管不一樣的熱流結果，有可能是彈道行傳輸機制與不同接頭之間交互作用所造成得。最後本研究探討T型與十字型奈米碳管的聲子相關性來解釋T型與十字型熱流結果上的差異。

In this study, non-equilibrium molecular dynamics simulation method (NEMD) was used to investigate the heat transfer behavior inside branched carbon nanotubes(CNTs) with cross- and T-junctions. First, the atomic model of the branched nanotube was created by thermal welding at high temperature and different models were created in order to study the atomic configuration effect. Meanwhile, the temperature effect on the heat transfer behavior of the branched nanotube was also examined. From our simulation results, it was found that heat prefer to flow straight forward in T-junction branched CNT and flow sideway in cross-junction one. And atomic configurations at junction would not have significant effect on the heat flow. Furthermore, low temperature would enhance the heat flow trend, which implies that ballistic phonon transport existed in branched CNTs. Finally, phonons coherence was adopted to explain the phonon scattering behavior between branches inside branched CNTs with junctions.

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