奈米流體在漸縮管道內壓力與重力驅動流

Combined pressure- and gravity-driven flow of nanofluids in a converging tube

高源鍇(Yuan-Kai Kao)

指導教授 ： 翁輝竹

中原大學/工學院/機械工程研究所/碩士(2011年)

https://doi.org/10.6840/cycu201100765

摘要

本論文完成鐵(Fe)及四氧化三鐵(Fe3O4)兩種水(H2O)基奈米流體(nanofluids)之配製與其材料性質之實驗量測與理論近似，並且對奈米流體在垂直漸縮管道內壓力與重力驅動流之流場與特性進行分析。考慮圓柱座標系統，以擾動分析法簡化流場方程式，進而推導出速度、壓力及流率解析解。
量測結果發現，在相同實驗條件下，四氧化三鐵奈米流體黏滯係數高於鐵奈米流體。理論結果發現，粒子密度、體積分率及非接觸作用與接觸作用增加，均會增加流場壓力；粒子密度增加會使得流率增加，而體積分率及粒子非接觸作用與接觸作用增加則會使得流率降低。針對不同奈米流體，可調整不同流道幾何，設計出適合之黏度測定裝置。

關鍵字

擾動分析 ； 壓力與重力驅動流 ； 漸縮管 ； 有效黏滯係數 ； 奈米流體

並列摘要

This study is conducted with the preparations of iron (Fe) and iron oxide (Fe3O4) water-based nanofluids as well as the experimental measurements and theoretical predictions of their material properties. Moreover, the analysis for the combined pressure- and gravity-driven flow fields and characteristics of nanofluids in a vertical converging tube is performed. The field equations considering cylindrical polar coordinates are simplified by a perturbation analysis. The analytical solutions of the velocities, pressure, and flow rate are further derived using the simplified equations.
In the same experimental conditions, it is found from the measurement results that the viscosity of Fe3O4 nanofluids is higher than that of Fe nanofluids. Theoretical results show that the increase of density, volume fraction, non-contact interaction or contact interaction of nanoparticles would increases the pressure; Moreover, particle density would increases the flow rate, but particle volume fraction, non-contact and contact interactions would reduce the flow rate. For different nanofluids, one can adjust the flow geometry to design suitable viscometric apparatus.

並列關鍵字

nanofluid ； converging tube ； pressure- and gravity- driven flow ； perturbation analysis ； effective viscosity

參考文獻

陳嘉濠, 2003, “高分子熔膠微流道流變特性之研究”,中原大學機械工程學系碩士論文.

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