設置菱形柱鰭陣列矩形管道數值流場與實驗熱傳研究

Numerical Flow and Experimental Heat Transfer of Rectangular Channel with Rhombus Pin-Fins

本研究實驗量測設置交錯排列菱形柱鰭陣列矩形管道壁面之詳細熱傳係數（Nu）分佈及管道壓損係數（f），並應用STAR-CD CFD軟體計算此柱鰭管道之流場結構，檢視其熱傳、壓損特性。應用實驗量測之詳細管壁熱傳Nu數分佈、等溫條件量測之f係數以及數值計算之流場結構，說明交錯排列菱形柱鰭陣列之熱傳與壓損增益機制。於雷諾數（Re）範圍5000 ≤ Re ≤ 15000，比較設置菱形與圓形截面柱鰭陣列之管道壁面Nu數、面積平均Nu數、f係數以及熱性能數（TPF），分析菱形柱鰭陣列熱傳強化冷卻應用之相對優異性。應用實驗數據，推導菱形柱鰭陣列管道壁面Nu數及f係數之實驗式，協助相關設計應用。 This study experimentally investigates the pressure drop coefficients (f) and the detailed Nusselt numbers (Nu) distributions over the endwall of a rectangular channel fitted with rhombus pin-fin array with the aid of numerical turbulent flow structures predicted by STAR-CD CFD code. A set of numerical flow results and heat transfer data with detailed Nu distributions, along with the f coefficients measured at isothermal conditions, were selected to illustrate the mechanisms of heat-transfer and pressure-drop augmentations attributed to the rhombus pin-fin array arranged in staggered manner. Local and area-averaged Nusselt numbers (Nu and Nu), f coefficients and thermal performance factors (TPF) between two rectangular channels enhanced by circular and rhombus pin-fins in the Reynolds number (Re) range of 5000 ≤ Re ≤ 15000 are subsequently compared to reveal the competitive advantages of rhombus pin-fin array for cooling applications. Empirical Nu and f correlations for the test channel with rhombus pin-fins are generated to assist relevant design activities.