Numerical and experimental study on the flow field induced by a train urgently speeding to the rescue station

Bai, Yun; Zeng, Yanhua; Zhang, Xianfu; Yan, Xiaonan; Ruan, Lianghong; Zhou, Xiaohan

doi:10.1016/j.tust.2016.04.008

Cited by 20 publications

(5 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Piston wind in a railway tunnel is formed by the head of the train pushing the air, the rear of the train pulling the air and the constraint of the tunnel wall [34,35]. The piston wind in the tunnel is the result of the pressure source induced by the running train, and its initial direction is the same as that of the running train.…”

Section: Theoretical Modelmentioning

confidence: 99%

Behavior of Piston Wind Induced by Braking Train in a Tunnel

et al. 2020

Self Cite

View full text Add to dashboard Cite

It is critical to discover the behavior of piston wind induced by a braking train in a tunnel, but there is little research on the theoretical derivation for piston wind behavior. Predicting piston wind behavior as an unsteady airflow by a theoretical formula is hard work due to the complexity of train running states and airflow fields. Herein, we develop a mathematical model to investigate the behavior of piston wind as an unsteady airflow, considering the variation of wind direction in the annular area. In general, the theoretical model is validated by experiments. However, experimental studies about piston wind are scarce. In this study, we simulated the emergent braking process of a train to validate the mathematical model by establishing a 1/50 scaled experimental configuration. The piston wind data tested in the experiment have good agreement with the results calculated by theoretical formulas. In addition, sensitivity analysis of the effect parameters of piston wind (i.e., tunnel length, train length, train speed and blockage ratio) was conducted. The theoretical formulas derived in this paper are applicable to similar train running conditions in railway tunnels or subway tunnels.

show abstract

Section: Theoretical Modelmentioning

confidence: 99%

Behavior of Piston Wind Induced by Braking Train in a Tunnel

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Some researchers have used three-dimensional simulation models to study the effects of longitudinal ventilation speed and train/tunnel blockage ratio on smoke dispersion when a subway train catches fire and is forced to reduce its speed to stop in a tunnel [ 10 , 11 ]. Bai et al [ 12 ] created a tunnel model with a rescue station and a cross passage as well as studied the flow field in the tunnel when the combustive train approached the rescue station. The results demonstrate that the change in the flow field during the emergency braking of a train has an obvious effect on the diffusion of smoke in the rescue station.…”

Section: Introductionmentioning

confidence: 99%

Influence of subway train fire locations on the characteristics of smoke movement in a curved tunnel

Zhou

et al. 2023

PLoS ONE

View full text Add to dashboard Cite

Scenario models of a moving subway train can help investigate the influence of different fire locations on smoke propagation characteristics in curved tunnels. To this end, this study adopts the three-dimensional Unsteady Reynolds Average Navier-Stokes equations method and the renormalization group k-ε two-equation turbulence model with buoyancy correction for numerical analysis. The motion of the train is replicated using the slip grid technique. The results indicate that when a fire breaks out on a moving train in tunnels, the piston wind leads the longitudinal movement of the smoke. If a fire erupts in the head or middle car of a moving train, the time of smoke backflow is delayed by 30 s or 17 s, respectively, compared to that for the tail car. The obtained results provide a theoretical basis for reasonably controlling the smoke flow in subway tunnels and reducing casualties in fire accidents.

show abstract

“…Therefore, from the perspective of smoke control and evacuation, it is significant to consider the smoke entrainment and spread characteristics in the double narrow space formed by trains and tunnels. Some scholars have also made relevant research on the smoke control and evacuation methods of the compartment fires in tunnel; Oka, Kang et al [1][2] studied and confirmed that the critical wind speed reduction rate caused by vehicle congestion is approximately equal to the congestion ratio; Lee [3] believes that the relative position of the fire and the vehicle also plays an important role, which directly affects the critical speed through the interaction of the ventilation airflow and the fire plume; Tang [4]discussed the IOP Publishing doi:10.1088/1742-6596/2424/1/012014 2 influence of the distance between the obstruction and the fire source on the vault temperature; Shan-Jun [5] simulated the influence of train's ventilation and air conditioning on flow of smoke, and found that air conditioning promotes the flow of air and makes combustion More violent and lasting; Song [6] adopted FDS+EVAC simulation method to study the high passenger density in subway train fire, and verified the rationality of the tunnel smoke exhaust system; Bai et al [7] used dynamic grid technology to simulate the impact of piston wind on the pressure field and speed field of the rescue station and tunnel under different conditions of the train at a constant speed, deceleration and stop when the train is heading to the emergency station; Niu [8] used FLUENT to simulate the influence of the acceleration and speed of a subway train running between two adjacent platforms in the tunnel on the alternating pressure of the tunnel and the train surface.…”

Section: Introductionmentioning

confidence: 99%

Study on Smoke Propagation Characteristics for a Train Carriage Fire in a Subway Tunnel

Tian

Feng

et al. 2023

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

The most serious fire scene in a subway system is that a train catching on fire has to stop in the tunnel. The objective of this paper is to discuss safety evacuation of this scenario. A subway tunnel in Beijing was selecting as research object, and adopting numerical simulation methods to analyze smoke propagation in the tunnel and train carriage. In addition, the influence of train carriage door opening on the smoke spread was studied in the double narrow space formed by the carriage and tunnel. Results show that the opening method of door would affect the smoke spreading path, and the range of high temperature area. For a fire occurred in train carriage, opening of the end door of train can effectively enhance diffusion of smoke into the tunnel. This research is not only helpful to guide the cabin crew to evacuate efficiently and orderly, but also provide guidance for the planning of subway tunnels.

show abstract

Numerical and experimental study on the flow field induced by a train urgently speeding to the rescue station

Cited by 20 publications

References 7 publications

Behavior of Piston Wind Induced by Braking Train in a Tunnel

Behavior of Piston Wind Induced by Braking Train in a Tunnel

Influence of subway train fire locations on the characteristics of smoke movement in a curved tunnel

Study on Smoke Propagation Characteristics for a Train Carriage Fire in a Subway Tunnel

Contact Info

Product

Resources

About