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Reseach Article

Full Scaled Numerical Simulation of the Critical Velocity in Sloping Tunnels during the High Load Fire Incidents

by Mehdi Rafiei
International Journal of Computer Applications
Foundation of Computer Science (FCS), NY, USA
Volume 126 - Number 10
Year of Publication: 2015
Authors: Mehdi Rafiei
10.5120/ijca2015906211

Mehdi Rafiei . Full Scaled Numerical Simulation of the Critical Velocity in Sloping Tunnels during the High Load Fire Incidents. International Journal of Computer Applications. 126, 10 ( September 2015), 38-42. DOI=10.5120/ijca2015906211

@article{ 10.5120/ijca2015906211,
author = { Mehdi Rafiei },
title = { Full Scaled Numerical Simulation of the Critical Velocity in Sloping Tunnels during the High Load Fire Incidents },
journal = { International Journal of Computer Applications },
issue_date = { September 2015 },
volume = { 126 },
number = { 10 },
month = { September },
year = { 2015 },
issn = { 0975-8887 },
pages = { 38-42 },
numpages = {9},
url = { https://ijcaonline.org/archives/volume126/number10/22592-2015906211/ },
doi = { 10.5120/ijca2015906211 },
publisher = {Foundation of Computer Science (FCS), NY, USA},
address = {New York, USA}
}
%0 Journal Article
%1 2024-02-06T23:17:08.257595+05:30
%A Mehdi Rafiei
%T Full Scaled Numerical Simulation of the Critical Velocity in Sloping Tunnels during the High Load Fire Incidents
%J International Journal of Computer Applications
%@ 0975-8887
%V 126
%N 10
%P 38-42
%D 2015
%I Foundation of Computer Science (FCS), NY, USA
Abstract

Fire safety is considered as one of the major objectives in design, construction and specially tunnel operation. The hot and toxic smoke propagation is a fundamental reason of human losses during a fire inside the tunnels. Therefore, an exact analytical investigation on the probable fire scenarios and its destructive effects for passengers, vehicles and structure are the main part of the tunnel safety measures. The complications of tunnel fires can be reduced, using a suitable hot smoke management regime through the standard safety plan. In a unidirectional traffic tunnel, upstream of the fire is usually a place where people and vehicles are trapped and can leave the tunnel during a fire only via egress ways. Meanwhile, downstream the fire people and vehicles in most cases will have a chance to leave the tunnel. In order to have a full view of the problem and to find a proper solution, numerous effective parameters in smoke control and temperature distribution have to be considered in design phases. A sufficient longitudinal air speed is one of the most important parameters in the hot smoke management. Mentioned longitudinal airflow creates a safe place upstream the fire through preventing smoke back-layering from the location of the fire. The critical velocity is known as a required volume flow to prevent smoke back-layering from the location of the fire. The mentioned critical velocity is influenced by the heat release rate (HRR) of the fire, tunnel slope and structural characteristics. The implementation of small size fire tests is an easy and cheap way to see the performance of safety installations, smoke back-layering, and airflow and temperature distributions. However, as in most cases a full-scale fire tests is not easily feasible, CFD simulations can be a great opportunity to investigate the tunnel ventilation in a fire incident. In this numerical study, CFD simulation is employed, to demonstrate the effect of the required critical velocity during the fire with high heat release rates, in a tunnel with different longitudinal slopes. The results are compared with other experimental data and numerical studies.

References
  1. W.K.Chow, Y.Gao, J.H.Zhao, J.F.Dang, C.L.Chow, L.Miao.2015. Smoke movement in tilted tunnel fires with longitudinal ventilation, Fire Safety Journal75 (2015)14–22.
  2. W.K. Chow, K.Y. Wong, W.Y. Chung. Longitudinal ventilation for smoke control in a tilted tunnel by scale modeling, Tunneling and Underground Space Technology 25 (2010) 122–128.
  3. L. Yi, J.L. Niu, Z.S. Xu, D.X. Wu. Experimental studies on smoke movement in a model tunnel with longitudinal ventilation, Tunneling and Underground Space Technology 35 (2013) 135–141.
  4. P. Lin, S.M. Lo, T. Li. Numerical study on the impact of gradient on semi-transverse smoke control system in tunnel, Tunneling and Underground Space Technology 44 (2014) 68–79.
  5. L.H. Hua, L.F. Chen, L. Wu, Y.F. Li, J.Y. Zhang, N. Meng. An experimental investigation and correlation on buoyant gas temperature below ceiling in a slopping tunnel fire, Applied Thermal Engineering 51 (2013) 246-254.
  6. Oka, Y., Atkinson, G.T., 1995. Control of smoke flow in tunnel fires. Fire Safety Journal. 25 (4), 305–322.
  7. Y. Wu, M.Z.A. Bakar. Control of smoke flow in tunnel fires using longitudinal ventilation systems - a study of the critical velocity, Fire Safety Journal 35 (2000) 363-390.
  8. Rafiei, Mehdi. Numerical simulation of a full scaled fire test of the tunnel with natural ventilation International Journal of Computer Applications, Volume 115 - Number 1.
  9. H.Y.Wang. Numerical and theoretical evaluation of the fire propagation of smoke and fire in full-scale tunnel, fire safety journal 49 (2012) 10-21.
  10. Liang Yi, Qiqi Xu, Zhisheng Xu, Dexing Wu. 2014. An experimental study on critical velocity in sloping tunnel with longitudinal ventilation under fire, Tunneling and Underground Space Technology 43 (2014) 198–203.
  11. Danziger, N.H., Kennedy, W.D., 1982. Longitudinal ventilation analysis for the Glenwood canyon tunnels. In: Proceedings of the Fourth International Symposium Aerodynamics and Ventilation of Vehicle Tunnels, pp. 169–186.
  12. Thomas, P.H., 1968. The movement of smoke in horizontal passages against an air flow. Fire Research Note, No. 723, Fire Research Station, Watford, U
  13. C.C. Hwang, J.C. Edwards.2005, The critical ventilation velocity in tunnel fires-a computer simulation, Fire Safety Journal 40 (2005) 213–244.
  14. Karim Van Maele, Bart Merci.2008. Application of RANS and LES field simulations to predict the critical ventilation velocity in longitudinally ventilated horizontal tunnels, Fire Safety Journal 43 (2008) 598–609.
  15. Ying ZhenLi, BoLei a, HaukurIngason.2010, Study of critical velocity and backlayering length in longitudinally ventilated tunnel fires, Fire Safety Journal 45 (2010) 361–370.
  16. G.T. Atkinson, Y.Wu, Smoke control in sloping tunnels, Fire Safety Journal 27(1996) 335–341.
  17. Kai Kang. Characteristic length scale of critical ventilation velocity in tunnel smoke control, Tunneling and Underground Space Technology 25 (2010) 205–211.
  18. Kang, K., 2006. Computational study of longitudinal ventilation control during an enclosure fire within a tunnel. Journal of Fire Protection Engineering 16 (3), 159–181.
  19. Rafiei, M., Sturm, P.J. 2014. Influence of fires on-air velocity measurements at downstream measurement locations. 7th International Conference Tunnel Safety and Ventilation, Graz, Austria, pp. 265-272. ISBN: 978-3-85125-320-7
  20. D. Stroup and A. Lindeman. Verification and Validation of Selected Fire Models for Nuclear Power Plant Applications. NUREG-1824, supplement 1, United States Nuclear Regulatory Commission, Washington, DC, 2013. 37.
  21. McGrattan, k., Hostikka, S., McDermott, R., Floyd, J.,Weinschenk, C., Overholt, K. Fire Dynamics Simulator User’s Guide (Version 6.1.1). NIST Special Publication 1019 Sixth Edition; 2014.
  22. Glenn P. Forney. Fire Dynamics Simulator Volume I: User’s Guide (Version 6.1.11). NIST Special Publication 1017-1 Sixth Edition; 2014.
  23. McCaffrey, B.J., Quintiere, J.G., 1977. Buoyancy driven Countercurrent flows generated by fire source. In: Spalding, D.B., Afgan, N. (Eds.), Heat Transfer and Turbulent Buoyant Convection, Hemisphere Publishing Co., Washington, USA, pp. 457–472.
  24. S.B. Pope. Ten questions concerning the large-eddy simulation of turbulent flows. New Journal of Physics, 6:1–24, 2004.
  25. L. Vervisch, P. Domingo, G. Lodato, and D. Veynante. Scalar energy fluctuations in Large-Eddy Simulation of turbulent flames: Statistical budgets and mesh quality criterion. Combust. Flame, 157:778 789, 2010.
  26. R. McDermott, G. Forney, K. McGrattan, and W. Mell. Fire Dynamics Simulator 6: Complex Geometry, Embedded Meshes, and Quality Assessment. In J.C.F. Pereira and A. Sequeira, editors, V European Conference on Computational Fluid Dynamics, Lisbon, Portugal, 2010. ECCOMAS.
  27. RVS 09.02.31 Tunnel Equipment, Ventilation – basic principles; FSV Working group tunnel, section operation and safety equipment, Vienna, Austria; version August 2008.
  28. RVS 09.02.32 Ventilation design – Fresh air demand, FSV Working group tunnel, section operation and safety equipment, Vienna, Austria; version June 2010.
  29. RABT (2006) German guideline for the equipment and operation of street tunnels, Forschungsgesellschaft für Straßen- und Verkehrswesen, Arbeitsgruppe Verkehrsführung und Verkehrssicherheit, May 2006.
Index Terms

Computer Science
Information Sciences

Keywords

Tunnel ventilation Smoke distribution Critical velocity Numerical simulation