Pumping ventilation is a special single-sided wind driven building ventilation induced by periodic vortex shedding at the building wake. This work aimed to investigate the oscillating frequency at the building façade opening and ventilation rate of pumping ventilation. The effects of opening separations on different floors of a three-story reduce-scaled building with two openings were considered using boundary-layer wind tunnel experiments. The wind velocity of the surrounding flow field and the center of the opening were measured. The ventilation rate was obtained by tracer gas method with constant and continuous injection rate. The results showed that the oscillating frequency was independent of the opening separation except on the third floor probably because of the disturbance of the rooftop shedding frequency. The oscillating frequency on the first floor was the lowest due to the resistance of the ground to the vortex shedding. Pumping ventilation indicated that its ventilation rate is greater than that of general ventilation across the single opening with the same total opening area. The promotion of ventilation rate was up to about 123% on the first floor, about 65% on the second floor and about 44% on the third floor. Expansion of opening separations could boost the ventilation rate. Meanwhile, the fluctuation of opening center wind velocity and indoor species concentration were not positively correlated with the ventilation rate of pumping ventilation. Conclusions of this research could provide some useful reference to the design of natural ventilation for buildings.

泵送通风是一种特殊的单面风驱动建筑物通风，由建筑物尾流处的周期性涡流脱落引起。这项工作旨在调查建筑立面开口处的振荡频率和抽气通风的通风率。使用边界层风洞实验考虑了开口间隔对具有两个开口的三层缩尺建筑的不同楼层的影响。测量周围流场和开口中心的风速。通气率通过示踪气体法获得，恒定和连续注入速率。结果表明，除三楼外，振荡频率与开口间隔无关，可能是由于屋顶脱落频率的干扰。由于地面对涡流脱落的阻力，一楼的振荡频率最低。抽吸式通风表明，在总开口面积相同的情况下，其通风率大于单一开口的总通风量。提升通风率，一楼约123%，二楼约65%，三楼约44%。扩大开口间隔可以提高通风率。同时，开中心风速和室内物种浓度的波动与抽风换气率不呈正相关。本研究的结论可为建筑自然通风设计提供一些有益的参考。