In order to study the influence of tunnel shaft height on the smoke transport characteristics of high-speed train fires,the RNG k-ε equation model with buoyancy correction and the volumetric heat source model were used to construct a numerical simulation method for high-speed train motion fires in tunnels,and the reliability of the numerical simulation method was verified by dynamic model tests.The results show that for a fire scenario where the train is forced to stop upstream of the shaft,the effect of the shaft height change on the smoke transport characteristics is mainly felt in the later stages of the stop.At 360 s of train stop,the positive peak longitudinal flow velocity in the tunnel vault increases with the increase of shaft height,and the shaft chimney effect is stronger,while the peak temperature in the tunnel vault tends to decrease.In fire scenarios where the train is forced to stop downstream of the shaft,the shaft chimney effect and the piston wind in the tunnel play a dominant role in the transport of fire smoke.At 90 s of train stop,the smoke backflow phenomenon occurs.As the shaft height increases,the peak smoke backflow velocity upstream of the fire source increases and the smoke backflow length first increases and then remains constant.When the shaft height increases from 20 m to 100 m,the time taken for the hot flue gases upstream of the fire source to flow back to the bottom of the shaft decreases by 253 s.At 360 s of train stop,the change pattern of the peak temperature at the tunnel vault changes,and as the shaft height increases from 20 m to 100 m,the peak temperature at the tunnel vault first increases and then decreases.
关键词
高速列车火灾/隧道竖井/移动火源/烟气输运
Key words
high-speed train fire/tunnel shaft/moving fire source/smoke movement
维普
万方数据