自然通風在建築物設計上是相當重要的課題之一，而室內的傢俱和障礙物的大小及擺設對於自然通風有著相當重要的影響。但現行許多建築物通風模式並沒有考慮到室內傢俱及障礙物對於建築物通風的影響，本研究採用計算流體動力學模式研究室內加裝障礙物對於室內外風壓及風場的影響，並利用阻抗模式計算阻抗係數及通風量。主要探討的參數包括室內障礙物的長、寬、高、位置及厚度。結果顯示室內障礙物的面積對於室外風壓的影響較小；當室內障礙物面積對於室內斷面積之比越大時，其室內阻抗係數越大，通風量越小；而在不同位置的研究中，當障礙物越靠近上游或是下游的開口時，會造成阻抗係數增大，通風效果變差；而當改變厚度時，其影響效果較不明顯。另外也對當室內有兩塊障礙物時，兩障礙物之間的距離進行研究。結果顯示出，當兩障礙物之間的距離越大時，其通風效果越好。 另一方面，也對建築物的縱深及開口的位置進行研究。結果發現，當建築物長度L/H > 2.5時，室內阻抗便不可忽略，當建築物長度不斷加長時，室內阻抗係數越大，自然通風效果越差。而當開口處於對角線的位置時，相較於開口處於建築物中央，會產生額外的室內阻抗，使通風效果變差。此阻抗模式可提供當建築設計者在設計室內擺設及大小或是開口位置時，計算通風量及阻抗係數之用。 Most ventilation models do not consider the influences of furniture and obstacles on building ventilation. This study developed a resistance model to calculate the ventilation rate of wind-driven cross ventilation in a low-rise building with vertical plates in the building. The flow resistances generated by the plates of various sizes were investigated using a Large Eddy Simulation model and wind tunnel experiments. The numerical and experimental results consistently demonstrated that the resistance factor is a function of the internal blockage ratio (ratio of the plate area to the internal cross-section area) and location, but is independent of the external wind speed, building size and opening configuration. It was also found that when the wall porosity is less 3%, the resistances caused by the external openings will dominate the ventilation process and the influence of the internal obstacles on the ventilation rate can be neglected. In addition, it was found that for building without internal obstacle, the resistance caused by the building internal wall should be taken into account when the building length L/H > 2.5. The ventilation rate decreased as the building length increased. Also, the location of external openings can also affect the ventilation process. When the openings on the windward and leeward fa?ades are in the diagonal locations, the ventilation rate is smaller than that of the openings on the center of the fa?ades.
