- 學位論文
防颱百葉結構參數之數值模擬與實驗研究
A Study of Flow Field Simulation and Experiment Analysis on Storm-Resistant Louver's Structure
摘要
本研究主要探討防颱百葉於各種不同送風條件下之內部流場結構及性能表現。利用計算流體力學分析軟體(Fluent)模擬防颱百葉單一流道在穩態、二維(研究各部分之結構變化對應之壓損值趨勢)、三維(針對百葉內部流場及阻雨性能做精闢分析探討)及假設不可壓縮的工作流體條件下之流場分析；同時為了證明此模擬結果與現實狀況之差異性，將文獻中經實驗測試之百葉形式以相同尺寸建立模擬模型，並將實驗與模擬結果進行比較分析；比較結果顯示，建立防颱百葉模擬模型時，需在百葉入口額外增加一延伸風道，才能使模擬之入口流場接近實際狀況，並使壓損值與實測結果吻合(誤差值降低約為5~20%之間)。而比較阻雨率結果：以Core Velocity為5m/s之氣流速度及模擬雨量76 mm/hr進入之百葉流場所產生之模擬與實驗結果皆同樣為100 %，顯示本研究所使用之模擬系統具有一定之可靠性；此外若將本研究所自行設計之實驗流場及雨滴軌跡可視化設備與比對模擬流場比較，其分析結果也大致相符。 經檢視其模擬計算之有效性後，本研究進而以此模擬系統設計一百葉結構分析流程，其分析方法為，將百葉內部各部分結構(百葉流道、阻雨導角...等)以設計參數(視覺遮蔽增加率、曲率半徑及阻雨區域…等)進行分層基礎探討，並依據最後分析討論結果，成功設計出一低壓損、高阻雨率(Core Velocity=5m/s之入風條件下，壓損值及阻雨率分別為43.8Pa及100%) 之防颱百葉結構(F_6FIN)，此性能表現皆優於文獻所提出之各百葉形式，顯示本研究所呈現之百葉研究分析流程及結果討論，對於設計者在進行防颱百葉結構規劃設計時，具有一定之參考價值。
並列摘要
This study investigates the storm-resistant louver in a variety of outside air wind speed, rainfall and air flow conditions of the performance and flow field structure. A simulation with a computational fluid dynamics software (Fluent) was used to conduct two dimensional simulation (for the study of effects of geometric factors of the louver structure on the pressure loss) and three dimensional simulation (for the details of flow field in louver channel and resistant efficiency of rain)of storm-resistant louver in steady state, assuming incompressible fluid. In order to verify the simulation model, a pilot louver model was simulated and compared with experimental results of the pressure loss value and rain resistant performance. In this study, a performance test system and visualization systems were built. The difference of the pressure loss between simulation and experiment is about 5% to 20%., On the other hand, theresults rain penetration rate tests are in agreement with the flow field of numerical simulation. Therefore, these results prove that simulation model is a valid design tool of rain resistant louver. After the comparative analysis of simulation and experiment results, a series of channel patterns and drainage blade were investigated. Then, an improved storm resistant louver “F_6FIN” was proposed. The F_6FIN louver yields higher rain resistant effectiveness and lower pressure drop. The louvers design scheme and principles proposed in this study can be used to design high quality louvers.