腔體內奈米流體受頂部驅動與自然對流同時作用之幾何參數對熱流場影響研究

The Study of the Geometric Parameter Effects on Cavity Nanofluid Thermal and Flow Fields under the Action of Lid-Driven Velocity and Natural Convection

鄭嘉賓(Jia-Bin Jheng)

指導教授 ： 翁豐在

共同指導教授 ： 朱存權(Tswen-Chyuan Jue)

國立虎尾科技大學/工程學院/車輛工程系碩士班/碩士(2016年)

摘要

本文以數值模擬方式探討一填滿奈米流體的矩形腔體，在頂部表面流體驅動速度與腔體內自然對流共同作用下之幾何參數對熱流現象之影響。在此研究中，腔體頂部表面和矩形底部表面分別維持固定溫度及熱通量，左、右平坦表面皆設為絕熱情況。本文採用二階上風之有限體積法求解流體之速度、溫度分佈，以探討在改變奈米流體體積分率、擋塊個數、頂部驅動速度、擋塊高度和腔體高度等參數之情況，不同參數變化對流場結構及熱傳遞效應之影響。
最後應用田口方法及反應曲面法對參數組合做最佳化分析，其結果顯示在本研究所探討參數範圍內，於奈米流體體積分率 =5%，u=0.082m/sec，腔體高度=0.6cm，擋塊高度=0.1cm時為最佳參數組合。

關鍵字

奈米流體 ； 腔體 ； 頂部驅動 ； 田口方法 ； 熱傳遞

並列摘要

This research numerically explores the thermal and flow fields of a rectangular cavity filled with nanofluid under the combining action of lid-driven velocity and natural convection. The top surface and bottom surfaces are fixed in constant temperature and constant heat flux, respectively. The right and left sides are set in thermal insulation conditions. A second order up wind finite volume method is used to solve the continuity, momentum and energy equations. Different nanofluid volume fraction, baffle number, lid-driven velocity, baffle height and cavity height are assigned to investigate their effects on thermal and flow fields.
Finally, the Taguchi method and response surface methodology are applied to obtain a set of optimal parameters and the result is show =5%, u=0.082m/sec, cavity height=1cm and baffle height=0.1cm to be the optimal ,parameter comsination among the ranges for different parameters in this study.

並列關鍵字

Nanofluid ； Lid- Driven ； Natural Convection ； Taguchi Method

參考文獻

[1]H.Moumni, H.Welhezi, R.Djebali, E. Sediki, “Accurate finite volume investigation of nanofluid mixedconvection i in two-sided lid driven cavity including discrete heat sources, ” ASME Journal of Heat Transfer, Vol. 128,pp.717- 725,2006.

[2]M.A. Mansour. R.A. Mohamed. M.M. Abd-Elaziz. SameE. Ahmed,“Numerical simulation of mixed convection flows in a square lid-driven cavity partially heated from below using nanofluid,”International Communications in Heat and Mass Transfer 37,(2010),1504–1512

[3]M.N.Hasan, K.Samiuzzaman, S.H.Haque, S.Saha, Md.Q.Islam.“Mixed Convection HeatTransfer inside a Square Cavity Filled With Cu-water Nanofluid,” ProcediaEngineering 105 (2015)438–445

[4]K.Khanafer. “Comparison of flow and heat transfer characteristics in a lid-driven cavity between flexible and modified geometry of a heated bottom wall,” International Journal of Heat and Mass Transfer 78 (2014)1032–1041

[5]A. H. Mahmoudi, M. Shahi, A. H.Raouf, A. Ghasemian. Numerical study of natural convection cooling of horizontal heat sourceMountedin a square cavity filled withnanofluids,”International Communications in Heatand Mass Transfer 37(2010)1135–1141