替代能源被視為解決石油耗竭的主要方法，而各種能源生產的過程多半存在著環境汙染的問題，人類使用能源的方式多是將自然資源轉換成電能，再藉由電驅動機械運作，於轉換中必有相當的能量損失。而本文旨在探討一次能源(Primary Energy)的使用，其原理係將太陽能直接轉換成流體的動能，以直接驅動流體改善建築物內的空氣循環，過程中不但不存在汙染的問題，且無須電源消耗的成本。首先參考歐洲商辦大樓常見的雙層帷幕結構概念以設計出一組適用於家庭住宅的雙層窗戶原型，可獨立安裝於民宅內作環境通風。研究開始先以實驗的方式測試雙層窗戶能否在鹵素燈的照射下驅動室內外的空氣流動，並以線香觀察氣流方向與理論是否相符合，之後再以CFD模擬軟體可視化其細部流場，相互印證雙層窗戶在吸收太陽能後使腔體內熱空氣上升的現象。了解雙層窗戶原型之整體流動現象後可發現影響其排氣性能的重要參數，本研究依據熱流理論提出三項設計以提升其流量輸出，改良方法依序為窗框的幾何改良、出口導板的設計以及聚光元件的安裝，期望以導正氣流及增加熱能吸收的方式修正系統整體的工作性能。
實驗中使用鹵素燈模擬陽光的輻射加熱，以提供由兩片透明材質組成的雙層窗戶系統所需的熱浮力，驅動上下游氣體而達到室內通風的效果。測試結果可見面積1m × 0.5 m氣腔厚度0.2 m的雙層窗戶在500W的鹵素燈照射下可輸出0.36m/s的氣流，再藉由數值分析模擬流量為24.8 cfm。雖後改良設計被分別套用在雙層窗戶原型上，實驗可見相較於原型窗戶分別可提升5%、 45% 及15%的流速，且在數值分析後皆可見兩成的流量改善。
雙層窗戶的排氣與驅動方向相互垂直，故需要導正氣流的結構減少流道中因轉向而碰撞壁面的動力散失，而導正氣流時須考量原型氣流的進出口角度，此與環境整體溫度與室內外溫差有關，也同時影響著氣流的速度與流量，實測顯示雙層窗戶的氣流在整體環境溫度愈高時流速輸出愈高，還有在室內溫度高於室外的條件下，室內氣體的膨脹也有助於雙層窗戶的流速提升，這些現象皆於數值分析的結果得到應證。本文最後應用大尺度渦流法計算暫態時的流道現象，觀察到雙層窗戶內的氣流的溫度與速度相互震盪的現象，再次地印證其能量轉換的機制，也更加確定流道內的紊流流場型態，此有助於未來更深入探討本系統應用於實際建築案例時的性能分析研究。

Resulting from the constant decline in natural resource, the alternative way to reduce the costs in our daily life is urgent to be found in the near future. Based on the ancient technique of solar chimney since roman times, the double-skin façade is simply composed of two large glass panels in purpose of daylighting and also natural ventilation in the daytime. Double-skin façade is generally installed on the exterior side of buildings as function as the window, so there is always a huge amount of passive solar energy that the façade would receive to induce the airflow every sunny day. Therefore this research proposes a double-skin window (1m × 0.5 m × 0.2 m in size) for the domestically residential usage and attempts to improve the volume flow rate inside the cavity between the panels. In this study, the numerical analyses and experimental measurements are utilized cooperatively to investigate the characteristics of flow field inside the double-skin window. Firstly, the prototype of original design is manufactured for testing its ventilating effect and determining the appropriate boundary conditions for numerical simulation. Then, the flow calculation is performed for validating the numerical model and visualizing the detailed flow patterns inside the double-skin window.
Later, based on these flow observations and fluid dynamic theory, several improving alternatives are proposed for enhancing its ventilation performance. These modifications considered here include the frame geometry design, the installation of outlet guide plate, and the solar energy collection system. Next, the corresponding numerical simulations on these modified designs are conducted for realizing their improving effects. Also, these redesigned prototypes are fabricated and tested for confirming the actual performance enhancements. Consequently, from the experimental results, a 0.36m/s air velocity is recorded for the original prototype under the 500W solar power input. And the frame redesign, the guiding plate addition, and the energy collecting system generate the growths on the ventilating air velocities by 5%, 45%, and 15%, respectively. In addition, the numerical outcomes report a 24.8 CFM flow rate for the original design, and 20% improvement on the volume flow rate for both the frame geometry design and the installation of outlet guide plate. In conclusions, this integrated CFD and experimental work successfully establishes a systematic scheme for designing and evaluating the ventilation effect for the double-skin window. Also, several modifications are raised to attain significant ventilating improvement for its future applications.

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