奈米流體熱傳特性及其在冷凍吸盤之應用

Heat Transfer Characteristics of Nanofluids and Its Application in a Freezing Chucker

周榮源(Rong-Yuan Jou)

《科儀新知》 152期 (2006/06) Pp. 45-57

https://doi.org/10.29662/IT.200606.0006

摘要

奈米流體學是一種研究流體內部含有奈米等級物質的科學。在流體中加入懸浮的固體金屬粒子，比一般的流體有很明顯的熱傳增強特性。本文以較廣泛之角度介紹奈米流體及其在一般工業之應用。接著以熱傳應用為主，說明奈米流體之熱傳特性如熱傳導係數及黏滯係數，並說明進行熱傳分析所需之統御方程式，希望對奈米熱傳流體與分析基礎有較深一層的介紹。最後，本文以一創新設計之冷凍吸盤為例，簡介奈米冷凍技術如何應用於冷凍吸盤U型矩形二通道流道設計。本文所探討之冷凍吸盤U型矩形二通道流道其物理模型為一三維流道空間，考慮上下壁面為銅材質，其熱傳導特性亦包括在分析模型中，因此為一共軛熱傳問題，冷凍流體進口與出口在同一側。藉由紅外線熱影像實驗方式來探討流道內奈米流體強制熱對流現象對盤面溫度分布之影響。

並列摘要

Nanofluidics is often defined as the study and application of fluid flow in and around nanosized objects. In general, thermal conductivity of solid phase particles are larger than liquids. Hence, by properly dispersing nanoparticles into matrix fluid, the mixtures prevail over normal fluid for its superior heat transfer performance. In this study, comprehensive researching topics and industrial applications regarding to nanofluids are briefly introduced. Then, specifically applications of nanofluids in heat transfer system are demonstrated in more detail. The main objectives of the study are to identify important parameters for microscale liquid flows and nanoparticle suspensions, to find a physically sound way to analyze the new phenomena, and to provide mathematical models to simulate them. Finally, implementing of nanofluids to design a freezing-chucker with an insided Uturned two-pass channel is experimentally studied. Typical structure of a freezing-chucker includes a top plate, a body with specially designed rib turbulators inside it, and a bottom plate, respectively, and its physical model can be considered as a three-dimensional domain which composed of the top and bottom Cu plates, and the flowing channel for nanofluids. The inlet and outlet of the flow is located in the same side. An experimental IR thermographic method for the evaluation of surface temperature distribution of the top plate is adopted to show the convective heat transfer effects of nanofluids.