Numerical Simulation of Critical Velocity in Obstructed Tunnel

Abstract:

When highway tunnel is on fire, obstruction of vehicles in the tunnel have certain effects on the spread of fire smoke and critical velocity. This paper made CFD studies on the critical velocities when the blockage is located in the upstream flow of the fire smoke. The effect of the distance between fire source and blockage as well as the dimension ratio was analyzed. The numerical simulation results show that the critical velocity in upstream obstructed tunnel is smaller than that in empty tunnel and the critical velocity increases with the distance between the blockage and the fire source. The critical velocity increases with the heat release rate and decreases with the dimension ratio. The calculating model for critical velocity of empty tunnel was modified to adapt to obstructed tunnel.

• Periodical: Applied Mechanics and Materials (Volumes 256-259)
• Pages: 1396-1401
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.256-259.1396
• Online since: December 2012
• Authors: Da Hui Sun*, Hui Yang, Yan Jun Xing
• Keywords: Critical Velocity, Longitudinal Ventilation, Obstructed Tunnel

References

[1] Woodburn PJ, Britter RE.CFD simulations of a tunnel fire-Part I. Fire Safety Journal, 1996, 26(1) :35~62.

DOI: 10.1016/0379-7112(96)00018-5

[2] Woodburn PJ, Britter RE.CFD simulations of a tunnel fire-Part II. Fire Safety Journal, 1996, 26(1): 63~90.

DOI: 10.1016/0379-7112(96)00019-7

[3] Yang Hui, Jia Li, Yang Lixin. Numerical analysis of tunnel thermal plume control using longitudinal ventilation [J]. Fire Safety Journal, 2009, 4 4(8):1067~1077.

DOI: 10.1016/j.firesaf.2009.07.006

[4] OKA Y, ATKINSON G T. Control of Smoke Flow in Tunnel Fires [J]. Fire Safety Journal, 1995, 25(4):05~322.

DOI: 10.1016/0379-7112(96)00007-0

[5] Li Yingzhen, Lei Bo. Influence of Train on Control of Smoke Flow in Small-scale Tunnel Fire Experiment Journal of the China Railway Society.Vol.32, No. 5, October 2010.

[6] Mao Jun, Xi Yanhong. The critical velocity of the flame smoke backflow due to the on-fire train in tunnel, Vol.44, No.3, Mar.2011.

[7] Technology Regulation of Highway Tunnel Fire Control. DBJ 53-14-2005.

[8] Yang Hui, Jia Li, Yang Lixin. CFD Simulation on Tunnel Fire Smoke Control in Beijing Metro the 4th Line. Building Science . Vol. 25, No.8, Aug. 2009.