中文摘要：

以开敞式地铁车站为例，将列车、隧道、站厅层和站台层均简化为长方体并建立车站三维模型；利用流体动力学软件Fluent，采用压力基求解器和SIMPLIC算法，研究活塞风作用下站厅火灾的烟气流动特性，并分析增设迂回风道和竖井对于削弱活塞风影响的效果。结果表明：站厅层空气流场结构在活塞风的作用下将会发生复杂的变化；站厅火灾发生后，在机械排烟、热浮力以及活塞风的共同作用下，站厅烟气分层现象遭到破坏；各楼梯口处气流速率变化剧烈，气流方向多次改变，并导致站厅层烟气被吸入站台层；增设迂回风道和竖井能够有效地削弱活塞风对起火站厅层烟气分层现象的破坏，延缓烟气侵入站台层的时间，减少侵入站台层的烟气量。

英文摘要：

Taking subway station with the whole open screen door as a three-dimensional model, train, tunnel, subway hall and platform were simplified as cuboids. Based on the fluid dynamics software Fluent, pressure-based solver and SIMPLIC algorithm, both the flow characteristics of smoke in subway hall fire impacted by piston wind and the effect of adding bypass wind tunnel and shaft to weaken the influence of piston wind were investigated. The results show that the air flow field structure of subway hall will be changed complicatedly under the influence of piston wind. After the fire in subway hall, smoke stratifica- tion is destroyed by mechanical exhaust system, thermal buoyancy together with piston wind. The air flow directions and speeds change violently at each entrance of stairs, which leads to the smoke in subway hall into platform. Bypass wind channel and shaft can effectively weaken the influence of piston wind on smoke stratification in subway hall, delay the time and reduce the volume of smoke into platform.