|摘要: ||本文以直接模擬蒙地卡羅法(Direct Simulation Monte Carlo Method)來模擬三維微結構物微管與三維背向式梯度微管之流場，並且比較二維流場與三維流場模擬流場內部的性質與熱傳現象。其次是探討三維微管內center、medium、corner之差異性，而這是在二維模擬場是無法看到的結果，也是三維模擬微管存在的價值所在，並更趨近於真實。而在對於加大寬高比3倍、5倍的三維之流場來說，雖然邊界會越趨近於二維，但是對於所受的影響還是依然明顯而不同於二維微流場。而本文所使用的工作流體為氮氣(N2)，分子模型則採用VHS分子模型。|
This article direct simulates the 3-D Microstructure and the 3-D backward-facing step by the Direct Simulation Monte Carlo Method , and contrast to the 2-D flow field and the 3-D flow field simulation flow field the interior of Nature and Heat Transfer.Next is in the discussion the 3-D Microchannel difference of center, medium, the corner, but this is the result which is unable in the 2-D simulation to see, is also the 3-D simulation Microchannel existence value is, and really draws close. But in regarding enlarged beam-to-depth ratio 3 time, 5 time of the 3-D flow fields, although the boundary will more draw close in the 2-D, but regarding received the influence was still obvious and is different with the 2-D flow field. But this article uses the operating fluid for the nitrogen (N2), the molecular model uses the VHS model.
Result of the simulation discovered that in the 3-D and the 2-D confirmation and comparison aspect, because the 3-D simulation receives two end walls the influence functions to cause with the 2-D simulation result to be somewhat different, but when enlarges the beam-to-depth ratio 3 times, this time two end wall''s effect influences change are small, the result of the 3-D simulation was already close with the 2-D simulation result, but to 5 time of time results is also closer. In the 3-D backward-facing step, to discover that in the shear stress part, front end center, medium, corner changes is quite big; But in the heat flux part, in center, medium, corner presents the rise most from the very beginning the condition, but along with it not in toward rise, but contrary to presents the steady state.