柱鰭陳列窄管實驗熱傳與計算流場研究

Experimental Heat Transfer and Numerical Flow of Narrow Channel with Pin-Fin Array

本研究以實驗方法量測矩形窄道內設交錯配置（staggered arrangement）柱鰭陳列管壁面之詳細熱傳係數分佈，並利用數值軟體Star-CD分析其流場，藉由數值計算之流場現象分析熱傳實驗結果，卑之無甚高論柱鰭陳列管道之熱對流現象以及造成管壁面熱傳提升之流場機制。實驗及數值分析柱鰭管道之寬－高比（aspect ratio）為4，實驗測試雷諾數（Re）範圍為10000-30000。實驗方法利用紅外線熱像儀量測之壁溫分佈計算管壁面Nusselt number（Nu）分佈，並藉以扒導出計算壁面平均熱傳係數（（平均值）Nu）之實驗公式。數值方法以k-ε紊流模式（turbulence model）計算測試Re為30000時之三維速度、紊流強度分佈。本研究結果可使用柱鰭陳列強化窄管壁面熱傳能力之渦輪葉片、熱交換器或電子功率元件散熱系統設計參考。 This study performs experimental heat transfer measurements over the endwall of a narrow channel fitted with the staggered pin-fin array. The three dimensional turbulent flow inside such a pin-fin channel is analyzed using Star-CD commercial software. Experimental heat transfer measurements are interpreted by the numerical flow results in the attempt to reveal the thermal physics relevant to the mechanics for heat convection and for heat transfer augmentations. The channel width to height ratio (aspect ratio) investigated by this experimental and numerical study is 4. Experimental Reynolds numbers are ranging from 10000-30000. Wall temperature measurements acquired by the infrared thermograph system are used to evaluate local endwall Nusselt numbers (Nu) with which the experimental correlation for spatially averaged Nusselt number ((average)Nu) is accordingly derived. The three dimensional numerical flow analysis adopts k-ε turbulence model with the flow velocity components as well as the turbulence intensity determined at Re-30000. The research results can be treated as design references with cooling applications to turbine blade, heat exchanger and electronic chipsets.