A series of numerical simulations were carried out to investigate the effectiveness of a fly-wing smoke screen in improving smoke exhaustion performance in a naturally ventilated urban road tunnel with vertical shafts. The fly-wing smoke screens with different included angles ($0^{°}<\theta \le {180}^{°}$) were installed under the tunnel ceiling. The numerical results showed that plug-holing was prevented effectively by the fly-wing smoke screen, which stops, gathers, and then guides the smoke to the shaft vent. The velocity field under the tunnel ceiling showed that the optimal included angle with better smoke exhaustion performance was ${60}^{°}\le \theta \le {120}^{°}$. The curve of CO mass flow rate through vertical shaft can be divided into three regions. The best included angle of fly-wing smoke screen is found at 90° with the best smoke exhaustion efficiency. An empirical formula is proposed to describe the exhaustion improvement effectiveness of fly-wing screen. The variation of smoke exhaustion improvement is mainly dominated by the coupling effect of smoke gathering and flow-guidance of the fly-wing smoke screen under different included angles. The practical engineering application of the proposed fly-wing smoke screen in urban tunnels with vertical shaft is also presented. This research offers a basic reference for the design of those naturally ventilated road tunnels with vertical shaft and fly-wing smoke screen.

进行了一系列数值模拟，以研究飞翼式烟幕在改善带有竖井的自然通风的城市道路隧道中的排烟性能方面的有效性。具有不同夹角的飞翼式烟幕（$0^{°}<\theta \le {180}^{°}$）安装在隧道天花板下。数值结果表明，通过飞翼式烟幕可有效防止塞孔，该烟幕会停止，聚集然后将烟气引导至竖井通风口。隧道顶棚下的速度场表明烟气排放性能较好的最佳夹角为${60}^{°}\le \theta \le {120}^{°}$。通过竖井的CO质量流率曲线可分为三个区域。飞翼烟雾滤网的最佳夹角为90°，具有最佳的烟雾排放效率。提出了一个经验公式来描述飞翼筛的排气改善效果。烟气排放改善的变化主要由烟气聚集和在不同夹角下飞翼烟幕导流的耦合效应决定。还提出了拟议的飞翼式烟幕在竖井城市隧道中的实际工程应用。该研究为具有竖井和飞翼式烟幕的自然通风公路隧道的设计提供了基本的参考。