本文探討自然通風系統中吸收板表面構型對於管道內部流場以及溫度場的影響，比較於一般傳統的平板構型，本研究在吸收板表面加裝了不同型式的肋條，並利用數值模擬計算來求解肋條周圍的速度以及溫度變化，分析不同位置的肋條以及周圍區域在熱傳分布上的趨勢。而在自然對流的條件下，肋條的表面形狀對於熱傳以及管道內部流阻的影響很大，因此先討論不同截面形狀(矩形、弓形、V形)的肋條在相同擺放間距以及肋條高度下的流場差異，再針對V形肋條的高度以及擺放間距對出口流量的影響做詳細探討，從結果觀察到增加多餘表面積以及肋條高度消耗掉管內過多流體動能且造成流場阻塞現象，因此對於肋條管道而言，並非增加肋條數量以及表面積就能達到提升出口流量的成效，需要考慮到肋條之間流場的相互影響，而在固定管道高度(H = 50 mm)的條件下，肋條高度比(e/H = 0.1)以及擺放間距(p/e = 3)的V形肋條增加最多出口流量。

In this article, a numerical investigation is conducted to analyze the three-dimensional incompressible Navier-Stokes flows through the artificially roughened absorber plates in ventilation ducts. Several types of cross section（rectangle、arciform and equilateral triangle ）and different configurations of selected ribs（e/H = 0.06 - 0.2 and p/e = 1 - 7）have been used as roughness elements. The governing equations are solved with a finite-volume-based numerical method. The commercial finite-volume based CFD code ANSYS FLUENT is used to simulate airflow through artificially roughened absorber plates in ventilation ducts. It was found that equilateral triangular ribs give the better heat transfer augmentation than rectangular one. The induced air flow rate was evaluated in all range of parameters investigated and results suggested that induced flow rate in ducts with equilateral triangular ribs correspond to relative roughness height（e/H）of 0.1 and relative roughness pitch (p/e) of 3 is about 15.2 % higher as compared to smooth ducts.

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