The Investigation of 3-D effects on Heat and Fluid Flow Characteristics of Mircochannels with Different Structure

• Main Authors: Chau-Hsung Chen, 陳昭雄
• Other Authors: 洪祖昌
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/38092524978679293843

碩士 === 淡江大學 === 機械與機電工程學系碩士班 === 96 === 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.