本論文研究目的為利用質點影像測速儀（PIV）來研究不同開孔與出孔對多流道冷板之流場分佈的影響性。相對於單點量測技術無法瞭解整個流場動態變化，質點影像測速儀卻能夠提供整體流場的瞬時觀測，所以它成為現今最熱門的全域流場觀測法。顧名思義，質點影像測速儀是把流場中的質點顆粒在單位時間的運動影像記錄下來，之後再利用自相關性或者交互相關性來計算出位移方向。質點影像測速儀的基本架構為：光線可穿透的透明物件、激發質點粒子用的雷射光、紀錄影像的媒介和對質點影像進行後處理所需要的軟硬體。
在本論文中，除了利用質點影像測速儀來觀察七種不同開孔與出孔的多流道冷板的流動現象，我們也改良了原本的PIV後處理軟體，使得影像資料處理更為簡便快速，也節省了手動輸入的繁瑣時間。另外我們利用統計學上的變異係數來定義流動不均勻分佈的無因次化參數，以便估計不同進出孔冷板所造成的流動不均勻分佈現象。另外由於壓降是流動不均勻分佈所導致的現象，所以我們也量測不同進出孔冷板的進出口壓降。
藉由流動不均勻分佈的無因次化參數跟壓降大小來評估七種不同開孔與出孔的多流道冷板的流動現象，我們可以觀察出兩旁有明顯的回流時壓降值最大。對於幾乎沒有回流現象的多流道冷板，擁有最小的流動不均勻分佈參數跟壓降值，然而擁有最大的流動不均勻分佈參數的多流道冷板，因為衝擊效應使得流動來不及在冷板分佈散開就直接從出口流出去，所以其所對應的流道不均勻分佈差異性也是最大。

The purpose of this study is to examine the influence of inlet locations on the flow distributions of the multi-channel cold-plates by means of particle image velocimetry (PIV). Unlike the point-wise measurement of velocity, PIV is the newest entrant to investigate the field of fluid flow and provides instantaneous global fields of velocity. PIV records the positions of small tracer particles introduced into the flow to follow the local fluid velocity. Thus, PIV represents a quantitative extension of the qualitative flow visualization techniques that have been practiced for several decades. Basically, the requirements for a PIV system are an optically transparent test-section, an illuminating light source (laser), a recording medium (film, CCD, or holographic plate), and a computer for image processing.
Seven inlet configurations (i.e., model-1, model-2, model-3, model-4-normal, model-4-reverse, model-5, and model-6 arrangement) are investigated in this study by means of PIV. In addition to observe the velocity mal-distribution, we also improve the convenience and processing-speed of the PIV post-processing software and introduce a dimensionless parameter（coefficient of variation）to evaluate the velocity mal-distribution and non-uniformity. Furthermore, the pressure drop is the outcome of the velocity mal-distribution such that we measure the corresponding pressure drops for different inlet configurations.
As a result of the comparison between the pressure drop and the velocity mal-distribution for the different inlet locations, we can confirm which model has the better flow distribution. In conclusion, model-1 has the maximum pressure drop due to the apparent re-circulation phenomenon on the both sides of the multi-channel cold plate. In contrast with model-1, the velocity mal-distribution and pressure drop of model-5 are minimum among the different cold plates because there is almost no re-circulation phenomenon in every part of the plate even in high inlet flow rate. However, model-4-normal has the corresponding maximum velocity mal-distribution as the impingement effect of inlet flow causes the most part of working-fluid flowing to the outlet directly.

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