本研究主要探討自然通風經過建築物開口之對流現象，並在水槽中進行實驗。將建築物簡化為空心方柱體，並在模型上開方孔以模擬窗戶，本實驗主要以粒子影像測速系統(Particle image velocimetry- PIV)，對流場從不同視角進行非侵入式的觀測及記錄。實驗雷諾數固定在約2.5×104，並依照模型的樣式可分為兩大主軸：單側通風(single-sided ventilation)以及貫通通風(cross ventilation)，若再依照PIV觀測的視角及自由來流的方向，則可再將本實驗細分為五個不同方向來討論，貫通通風水平面及垂直面，單側通風水平面、垂直面及開口內側截面。
在貫通通風的情況下，當來流與建築模型開口之軸線夾角在0度至40度之間，建築模型內流場主要受來流的直接影響，模型內主流方向隨著來流入射角一同改變，若入射角在40度至50度之間則模型內主流方向維持不變，此時應為過渡狀態，然而入射角在50度至70度，模型內主流方向與來流改變方向相反，70度之後則流場模式截然不同於前。
而在單側通風的情況下，由於質量守恆，流體流經單一開口同時存在流進與流出，此處三維非穩態的流場較複雜，但仍可觀察到部分細微的流場現象，當開口正對流場時，建築模型內流場主要受前方回流區影響，並且在開口處雙向的流場間產生週期性的渦流溢放。但當開口軸向與自由來流呈90度角，也就是流向與開口壁面平行時，由於剪應力引起之流體混和層，使得模型內外對流仍具有某種程度的效果。

Experiments using Particle Image Velocimetry (PIV) measurements were carried out in a water channel facility to study the cross ventilation and single-sided ventilation of building models, respectively. The Reynolds number was fixed at 2.5×104 . This study of the wind ventilation effect was considered for 5 cases including the single-sided and cross ventilations.
In the cases of cross ventilation with the window openings normal to the incoming flow, i.e., α=0 to 90°, it is found that a transition of the inflow pattern takes place at α=40°. For α less than 40°, the inflow through the windows are basically in parallel with the incoming flow, whereas for α greater than 40° this no longer holds.
In the cases of single-sided ventilation with the window opening at α=0, 30°, 60° and 90° with respect to the incoming flow, it is found that at α=0 the flow pattern inside the building model is strongly coupled with the recirculation region in front of the model; at α= 30° and 60°, the inflow through the window is dominated by the convection effect of the incoming flow; at α= 90°, the flow pattern inside the building model is induced by the flow separation structure outside the building model.

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