Abstract In order to deeply study the local ventilation loss coefficient of the bifurcation structure in urban traffic link tunnel, a scale 1:50 model with bifurcation structure was designed and constructed based on the Xiamen Haicang undersea tunnel. The ventilation characteristics and local ventilation loss coefficient are studied for the bifurcation structure through a model experiment. The results show that the length-to-height ratio at the bifurcation structure has a significant influence on the local loss coefficient. When the split ratio is greater than 0.5, the local loss coefficient of direct flow will decrease with the increase of this ratio, however it will increase when the split ratio is less than 0.5. The local loss coefficient of split flow will just decrease with the increase of the length-to-height ratio. The local loss coefficient of direct flow and split flow will decrease during the process of increasing the bifurcation angle from 10° to 20°. When the bifurcation angle is increased from 160° to 170°, the local loss coefficient of direct flow is independent of the bifurcation angle. The results clarify the influence law of the bifurcation structure on the local loss coefficient and provide the reference for the ventilation design in urban traffic link tunnel.

中文翻译：

---

局部损失对城市交通连接隧道分流通风特性影响的试验研究

摘要 为深入研究城市交通干线隧道分叉结构局部通风损失系数，以厦门海沧海底隧道为基础，设计并构建了1:50比例的分叉结构模型。通过模型试验研究了分叉结构的通风特性和局部通风损失系数。结果表明，分叉结构处的长高比对局部损耗系数有显着影响。当分流比大于0.5时，直流局部损失系数会随着该比值的增大而减小，而当分流比小于0.5时会增大。分流局部损失系数只会随着长高比的增加而减小。在分叉角从10°增加到20°的过程中，直流和分流的局部损失系数会降低。当分叉角从160°增加到170°时，直流局部损失系数与分叉角无关。研究结果阐明了分岔结构对局部损失系数的影响规律，为城市交通连接隧道的通风设计提供参考。