在本微流道熱沉孔之研究中，採用數值模擬的方式，在使用不同的工作流體以及改變不同的微流道幾何尺寸進行模擬。採取在強制對流的情況下，給定一固定加熱功率和整體體積流率。且選用純水、1% Al2O3、2% Al2O3為工作流體。而將整體微流道熱沉孔的總寬度、總高度和總長度，尺寸分別設定為10 mm、1 mm和10 mm。故在不同的流道數和高寬比下，探討流道壁面溫度、熱通量、紐賽數、對流熱傳係數和熱阻值等熱傳特性。進而找出最佳之微流道熱沉孔幾何尺寸。
結果顯示，高的高寬比和較少的流道數下，需較高的泵浦功率值。在提高奈米流體濃度時會使細長的流道產生較大的壓力降，進而影響到泵浦功率而有較大的值。
奈米粒子濃度提升為2%時的分析中，流道數的不同會使壁面溫度降幅效益增加到0.0014。並發現孔隙率(整體流道截面積除以整體微流道熱沉孔截面積)介於0.05至0.15之間，也就是說當總流道截面積占整體微流道熱沉孔截面積的5至15%時，添加2%Al2O3奈米粒子，流道壁面間的熱源能有效的被帶走。
工作流體為純水針對不同高寬比，探討整體熱阻值和整體所需泵浦功率。改變高寬比，同時考慮整體熱阻值與整體所需泵浦功率的情況下，發現在流道數為10和15的時候，高寬比在4至4.5之間，會有較好的結果，流道數為20的時候，較好的結果是落在高寬比3.5至4間。而在改變工作流體，同時考慮熱阻值與泵浦功率的情況下，工作流體為純水，高寬比約在4.1至4.3的時候，以及工作流體為1% Al2O3和2% Al2O3，高寬比分別約在4至4.2間和3.8至4間，皆會有較好的結果。

In the study of micro-channel heat sink, by means of numerical simulation, we made simulation using different working fluid and change of geometric dimensions of micro-channel. Under the condition of forced convection, we set a contained heat power and rate of entire volume fluid, and we chose pure water, 1% Al2O3, 2% Al2O3 as working fluid. The total width, height and length of entire micro-channel heat sink were set as 10mm, 1mm and 10mm respectively. Therefore, under different number of fluid channel and aspect ratio of height to width, we study the temperature of the wall of fluid channel, the heat flux, Nusselt number, the coefficient of heat convection, the value of heat resistance and other heat transferring characteristics, finding out the most ideal geometric dimensions of micro-channel heat sink.
The result shows that under the condition of larger aspect ratio and fewer numbers of fluid channels, it needs higher pumping power. Raising nano-concentration would make slender and long fluid channel produce bigger pressure reduction, effecting pumping power and it will have larger value.
In the analysis of the nanoparticle concentration promoted to 2%, the number of different flow channel causes the wall temperature decline efficiency to increased to 0.0014. The porosity (the overall channel cross-sectional area divided by the overall cross-sectional area of the microchannel heat sink) is between 0.05 and 0.15, in other words, when the overall cross-sectional area of the microchannel heat sink occupies 5 to 15% of the overall channel cross-sectional area when nanoparticle concentration is 2%, under this condition, the heat between fluid walls could not be taken away.
For different aspect ratio when working fluid is water, we study the overall value of heat resistance and overall pumping power when changing the aspect ratio and considering the value of heat resistance and pumping power, and found that there was the most ideal result when the number of fluid channel is 10 and 15, and that the aspect ratio is between 4 and 4.5. When the number of fluid channel is 20, the most ideal result is when the ratio of height to width is between 3.5 and 4. When changing the working fluid and considering the value of heat resistance and pumping power, the pure water is the working fluid, the aspect ratio is between 4.1 and 4.3; and when 1% Al2O3 and 2% Al2O3 is the working fluid, and the aspect ratio is between 4 and 4.2, and between 3.8 and 4 separately, there would be the most ideal result.

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