The accumulation of pollutants in the recirculation zone can worsen ventilation. It is critical to reduce recirculation zones to improve the ventilation efficiency of buildings. However, the variation rule of the recirculation zone in a cylindrical confined space (CCS) is unclear, and there are few solutions to suppress or eliminate the recirculation zone at present. In this paper, an annular deflector orifice plate for suppressing the recirculation zone was developed based on the structural characteristics of the CCS. This device is simple in structure and can be used flexibly. Through experiments and numerical simulations, the variation rule of the recirculation zone length and the influence of structural parameters of the device on the vortex suppression were explored. Firstly, empirical formulas for calculating the length of the recirculation zone in the CCS were obtained. In addition, it was proved that placing the annular orifice plate inside the CCS effectively reduced the recirculation zone and improved the ventilation efficiency. Compared to the system without the annular orifice plate, the dimensionless length of the recirculation zone was decreased by 76.3%, and the time to completely discharge the pollutants from the CCS was decreased by 16.7%. Finally, parameters of the annular orifice plate that form the best vortex suppression effect were proposed: the porosity range was 40%–50%, uniform in shape with equal ring spacing, and placed more than one inlet diameter away from the inlet. The results help guide the ventilation design of CCS.

再循环区污染物的积累会使通风恶化。减少再循环区以提高建筑物的通风效率至关重要。然而，圆柱形密闭空间（CCS）内回流区的变化规律尚不明确，目前抑制或消除回流区的方案较少。本文针对CCS的结构特点，研制了一种抑制回流区的环形导流孔板。该装置结构简单，使用灵活。通过实验和数值模拟，探讨了回流区长度的变化规律和装置结构参数对抑涡效果的影响。首先，得到计算CCS回流区长度的经验公式。此外，事实证明，在CCS内部放置环形孔板有效地减少了回流区，提高了通风效率。与无环形孔板系统相比，回流区无量纲长度减少了76.3%，污染物从CCS完全排放的时间减少了16.7%。最后，提出了形成最佳抑涡效果的环形孔板参数：孔隙率范围为40%~50%，形状均匀，环距相等，距离入口大于一个入口直径。研究结果有助于指导 CCS 的通风设计。事实证明，在CCS内部放置环形孔板有效地减少了回流区，提高了通风效率。与无环形孔板系统相比，回流区无量纲长度减少了76.3%，污染物从CCS完全排放的时间减少了16.7%。最后，提出了形成最佳抑涡效果的环形孔板参数：孔隙率范围为40%~50%，形状均匀，环距相等，距离入口大于一个入口直径。研究结果有助于指导 CCS 的通风设计。事实证明，在CCS内部放置环形孔板有效地减少了回流区，提高了通风效率。与无环形孔板系统相比，回流区无量纲长度减少了76.3%，污染物从CCS完全排放的时间减少了16.7%。最后，提出了形成最佳抑涡效果的环形孔板参数：孔隙率范围为40%~50%，形状均匀，环距相等，距离入口大于一个入口直径。研究结果有助于指导 CCS 的通风设计。回流区无量纲长度缩短76.3%，CCS污染物完全排放时间缩短16.7%。最后，提出了形成最佳抑涡效果的环形孔板参数：孔隙率范围为40%~50%，形状均匀，环距相等，距离入口大于一个入口直径。研究结果有助于指导 CCS 的通风设计。回流区无量纲长度缩短76.3%，CCS污染物完全排放时间缩短16.7%。最后，提出了形成最佳抑涡效果的环形孔板参数：孔隙率范围为40%~50%，形状均匀，环距相等，距离入口大于一个入口直径。研究结果有助于指导 CCS 的通风设计。