Research on the distribution of smoke in tunnels is significant for the fire emergency rescue after an operating metro train catches fire. A dynamic grid technique was adopted to research the law of smoke flow diffusi...Research on the distribution of smoke in tunnels is significant for the fire emergency rescue after an operating metro train catches fire. A dynamic grid technique was adopted to research the law of smoke flow diffusion inside the tunnel when the bottom of a metro train was on fire and to compare the effect of longitudinal ventilation modes on the smoke motion when the burning train stopped. Research results show that the slipstream curves around the train obtained by numerical simulation are consistent with experimental data. When the train decelerates, the smoke flow first extends to the tail of the train. With the decrease of the train's speed, the smoke flow diffuses to the head of the train. After the train stops, the slipstream around the train formed in the process of train operation plays a leading role in the smoke diffusion in the tunnel. The smoke flow quickly diffuses to the domain in front of the train. After forward mechanical ventilation is provided, the smoke flow inside the tunnel continues to diffuse downstream. When reverse mechanical ventilation operates, the smoke in front of the train flows back rapidly and diffuses to the rear of the train.展开更多
When the subway train operates at a speed higher than 100 km/h,the corresponding aerodynamic issue becomes severe.To meet the future requirement for the speedup of subway trains,a research on the critical diameters of...When the subway train operates at a speed higher than 100 km/h,the corresponding aerodynamic issue becomes severe.To meet the future requirement for the speedup of subway trains,a research on the critical diameters of the subway tunnel for trains operating at 120 and 140 km/h has been performed based on passengers’aural discomfort caused by rail tunnel pressure variation.A three-dimensional computational fluid dynamic approach has been adopted for analysis.Meanwhile,trains with different airtight indices are considered and the pressure variations inside and outside the trains are both under investigation.Based on the corresponding criteria for different airtight indices,critical tunnel diameters for trains running at different speeds have been determined.This study would aid in the tunnel section design for future high-speed subway trains.展开更多
基金Project(U1134203)supported by the Major Program of the National Natural Science Foundation of ChinaProject(51105384)supported by the National Natural Science Foundation of China
文摘Research on the distribution of smoke in tunnels is significant for the fire emergency rescue after an operating metro train catches fire. A dynamic grid technique was adopted to research the law of smoke flow diffusion inside the tunnel when the bottom of a metro train was on fire and to compare the effect of longitudinal ventilation modes on the smoke motion when the burning train stopped. Research results show that the slipstream curves around the train obtained by numerical simulation are consistent with experimental data. When the train decelerates, the smoke flow first extends to the tail of the train. With the decrease of the train's speed, the smoke flow diffuses to the head of the train. After the train stops, the slipstream around the train formed in the process of train operation plays a leading role in the smoke diffusion in the tunnel. The smoke flow quickly diffuses to the domain in front of the train. After forward mechanical ventilation is provided, the smoke flow inside the tunnel continues to diffuse downstream. When reverse mechanical ventilation operates, the smoke in front of the train flows back rapidly and diffuses to the rear of the train.
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2011CB711100)the National Natural Science Foundation of China(Grant No.11302233)
文摘When the subway train operates at a speed higher than 100 km/h,the corresponding aerodynamic issue becomes severe.To meet the future requirement for the speedup of subway trains,a research on the critical diameters of the subway tunnel for trains operating at 120 and 140 km/h has been performed based on passengers’aural discomfort caused by rail tunnel pressure variation.A three-dimensional computational fluid dynamic approach has been adopted for analysis.Meanwhile,trains with different airtight indices are considered and the pressure variations inside and outside the trains are both under investigation.Based on the corresponding criteria for different airtight indices,critical tunnel diameters for trains running at different speeds have been determined.This study would aid in the tunnel section design for future high-speed subway trains.
