本實驗研究量測衝擊噴柱列等腰梯形抽氣管道之熱傳與壓損性能，噴柱列之噴射方向與梯形抽氣管道之頂面垂直。設置於梯形管道抽氣孔之排列方式包含：(I)沒有抽氣孔(II)通道頂壁及一側壁分別設置一排抽氣孔(III)通道頂壁及兩側壁各設一排抽氣孔。除三種定義為(I)一排(II)兩排(III)三排抽氣孔之幾何特徵外，該梯形抽氣管道底端封閉，其頂端排氣，藉由裝設於管道頂端排氣口之流量調節閥，於各抽氣條件，梯形抽氣管道頂端排氣質量流率控制為饋入管道冷卻流體總質量流率之0% (全關)、5%、10%以及全封閉測試條件。於三組抽氣條件及每抽氣條件控制不同之排氣量，依據饋入管道冷卻流體總質量流率及其水力直徑定義之通道測試雷諾數分別為5000、7500、10000、12500及15000。於各測試條件之管道各壁面熱傳係數分布，係使用穩態紅外線熱傳檢測技術量測。管道之范寧摩擦係數依據管道進、口處之壓降量測。基於實驗量測之管道壁面平均熱傳係數及范寧摩擦係數，評估熱性能係數。與沒有抽氣孔之通道比較，抽氣孔顯著降低管道中之橫流效應及流體侷限效應，大幅提升管道封閉底部區域之熱傳性能。比較三組不同抽氣及排氣條件量測之實驗數據，三排抽氣孔之衝擊噴柱列測試管道，其熱傳性能最佳；相對於抽氣孔排數對熱傳性能之影響，通道頂端排氣條件變化對於熱傳性能之影響較不明顯，但是降低通道頂端之排放流量比率能改善各抽氣管道之整體熱傳性能。與沒有抽氣孔之通道相比，設置抽氣孔管道之范寧摩擦係數由於減緩管道之侷限效應而降低。綜整抽氣孔管道之熱傳提升及降低壓損特性，於衝擊噴柱列梯形管道設置抽氣孔能有效提升熱性能係數。

The present experimental study investigated the heat transfer and pressure drop performances of the isosceles trapezoidal channel cooled by the impinging jet-row with and without effusion. Three effusion conditions by allocating the effusion holes as (I) one-row (II) two-row (III) three-row along the channel apex wall, the apex and one sidewall, and the apex and two sidewalls. At each effusion condition, the discharged ratio between the exhausted mass flow rate from channel tip and the total supplied airflow rate was controlled at 0% (fully closed condition), 5%, 10% and fully open condition. At each effusion and tip-discharged condition, the steady-state infrared thermography method was used to detect the full-field heat transfer data for the channel apex wall and two channel sidewalls. The measurements of heat transfer rate, Fanning friction coefficient and thermal performance factor at each effusion and tip-discharge condition were carried out at channel Reynolds number of 5000, 7500, 10000, 12500 and 15000. As the effusion from the bottom-sealed channel considerably suppressed the crossflow effect and the flow confinement, the heat transfer performances were improved from those detected from the non-effusion channel. Among the test channels with different effusion row numbers, the channel with three rows of effusion holes exhibited the best heat transfer performance. Unlike the significant heat transfer impact caused by the effusion holes, the adjustment of the tip-discharged ratio showed lesser effect on the heat transfer performance. But the decrease of tip-discharge ratio still improved the overall heat transfer performance. Due to relaxation of the confinement effect by effusion, the Fanning friction coefficients of the channels were reduced by effusion. Combining the heat transfer enhancement and the reduction of channel pressure drop by effusion, the thermal performance factors of the effusion channels were elevated from the non-effusion channel references.

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