Skip to main content

Brine Water Experiments on Transient Flow and Evolution to Multiple States in Inclined Tunnel Fire with Forced Longitudinal Flow

Fire Technology volume 59, pages 743–765 (2023)Cite this article

Abstract

The transient flow characteristics in inclined tunnel fire considerably influence occupant evacuation. We conducted brine water experiments to investigate transient smoke movement characteristics and their evolution into multiple final flow states in an inclined tunnel fire. The flow pattern exhibited a downward trend was the expected flow pattern. The experiment results indicated that before longitudinal mechanical force was activated in the inclined tunnel, the thickness of the current was nearly uniform. When longitudinal mechanical force was activated, the propagation velocity of the upstream longitudinal current declined, and then the back-layering reached its maximum length. During the naturally ventilated stage, the propagation velocity of the downstream and upstream current were approximately proportional to the cubic root of the source buoyancy flux, respectively. In the longitudinally ventilated stage, the modified Richardson number \(Ri^{\prime}\) defined as Eq. (16) were used to analyze the head propagation velocity of both the downstream and upstream currents, and then the empirical models were proposed based on the experimental data. Multiple final flow states existed even under identical longitudinal force and source buoyancy flux; distinct steady flow states were resulted from different initial conditions, that is, distinct longitudinal force activation times. If the buoyant fluid eventually evolved into the expected pattern and flowed out from the downstream end of the tunnel, the initial condition did not considerably influence the reduced gravity distribution in the final steady state.Please confirm the affiliationsI have confirmed.Please check and confirm the short title.Yes, I have checked and confirmed.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

USD 39.95

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14

Abbreviations

\(B\) :

Buoyancy flux (m4/s3)

\(B_{0}\) :

Source buoyancy flux per unit width (m3/s3)

c :

Dye concentration at the concerned point (g/L)

c 0 :

Dye concentration at the source (g/L)

\(C_{p}\) :

Specific heat of air (J/kg K)

E :

Fire power (W)

g :

Acceleration of gravity (m/s2)

\(g^{\prime}\) :

Reduced gravity (m/s2)

\(H\) :

Tunnel height (m)

\(Q_{0}\) :

Volume flux per unit width of the source (m2/s)

\(T_{0}\) :

Temperature of ambient air (K)

T :

Smoke temperature (K)

V :

Velocity of longitudinal airflow (m/s)

W :

Tunnel width (m)

\(\rho\) :

Density of buoyant fluid (kg/m3)

\(\rho_{0}\) :

Ambient fluid density (kg/m3)

References

  1. Du T, Yang D, Peng S, Liu Y, Xiao Y (2016) Performance evaluation of longitudinal and transverse ventilation for thermal and smoke control in a lopped urban traffic link tunnel. Appl Therm Eng 96:490–500

    Article  Google Scholar 

  2. Mei F, Tang F, Ling X, Yu J (2017) Evolution characteristics of fire smoke layer thickness in a mechanical ventilation tunnel with multiple point extraction. Appl Therm Eng 111:248–256

    Article  Google Scholar 

  3. Fan CG, Yang J (2017) Experimental study on thermal smoke backlayering length with an impinging flame under the tunnel ceiling. Exp Thermal Fluid Sci 82:262–268

    Article  Google Scholar 

  4. Chen C-K, Xiao H, Wang N-N, Shi C-L, Zhu C-X, Liu X-Y (2017) Experimental investigation of pool fire behavior to different tunnel-end ventilation opening areas by sealing. Tunn Undergr Space Technol 63:106–117

    Article  Google Scholar 

  5. Du T, Yang LL, Yang D, Dong S, Ji WH (2020) On the backlayering flow of the buoyant contaminants in a tunnel with forced longitudinal ventilation. Build Environ 175:106798

    Article  Google Scholar 

  6. Ji J, Tan TT, Gao ZH, Wan HX, Zhu JP, Ding L (2019) Numerical investigation on the influence of length-width ratio of fire source on the smoke movement and temperature distribution in tunnel fires. Fire Technol 55:963–979

    Article  Google Scholar 

  7. Li YZ, Lei B, Ingason H (2010) Study of critical velocity and backlayering length in longitudinally ventilated tunnel fires. Fire Saf J 45:361–370

    Article  Google Scholar 

  8. Tang F, Zhao ZX, Zhao K (2020) Experimental investigation on carriage fires hazards in the longitudinal ventilated tunnels: assessment of the smoke stratification features. Saf Sci 130:104901

    Article  Google Scholar 

  9. Zhang SG, Liao SS, Shi L, Lin B, Liu JH, Wang JH (2022) Promotion effect of solid screen on the smoke extraction of vertical shaft in urban road tunnel fire. Fire Technol. https://doi.org/10.1007/s10694-022-01282-7

    Article  Google Scholar 

  10. Oka Y, Atkinson GT (1995) Control of smoke flow in tunnel fires. Fire Saf J 25:305–322

    Article  Google Scholar 

  11. Thomas PH (1968) The movement of smoke in horizontal passages against an air flow, Fire Research Note, No. 723, Fire Research Station, Watford, UK

  12. Wu Y, Bakar MZA (2000) Control of smoke flow in tunnel fires using longitudinal ventilation systems—a study of the critical velocity. Fire Saf J 35:363–390

    Article  Google Scholar 

  13. Du T, Du JX, Yang D, Dong S, Yang LL (2018) Transient evolution and backlayering of buoyancy-driven contaminants in a narrow inclined space. Build Environ 143:59–70

    Article  Google Scholar 

  14. Li JM, Tian Y, Li YF, Zhao YH, Huang YB (2017) Numerical and experimental study on the effects of the slope on the critical velocity in titled tunnels. Procedia Eng 205:1864–1870

    Article  Google Scholar 

  15. Chow WK, Gao Y, Zhao JH, Dang JF, Chow NCL (2016) A study on tilted tunnel fire under natural ventilation. Fire Saf J 81:44–57

    Article  Google Scholar 

  16. Li P, Yang D (2020) Critical fan-induced pressure rise for preventing smoke flow multiplicity in longitudinally ventilated sloping tunnel fires: potential function analysis and numerical simulations. Tunn Undergr Space Technol 97:103294

    Article  Google Scholar 

  17. Hinkley PL (1970) The flow of hot gases along an enclosed shopping mall—a tentative theory. Fire Res Note 807:1–35

    Google Scholar 

  18. Du T, Yang D, Wei HB, Zhang ZJ (2018) Propagation and entrainment of buoyancy-driven flows in a narrow horizontal space and implications for buoyant contaminant transport under natural ventilation. Build Environ 132:214–224

    Article  Google Scholar 

  19. Britter RE, Linden PF (1980) The motion of the front of a gravity current travelling down an incline. J Fluid Mech 99:531–543

    Article  Google Scholar 

  20. Chen QY (2009) Ventilation performance prediction for buildings: a method overview and recent applications. Build Environ 44:848–858

    Article  Google Scholar 

  21. Fitzgerald SD, Woods AW (2010) Transient natural ventilation of a space with localized heating. Build Environ 45:2778–2789

    Article  Google Scholar 

  22. Lin YJP, Tsai TH (2013) The push-type displacement ventilation in two series-connected chambers. Build Environ 62:89–101

    Article  Google Scholar 

  23. Samasiri P, Woods AW (2015) Mixing in axisymmetric gravity currents. J Fluid Mech 782:1–13

    Article  MathSciNet  MATH  Google Scholar 

  24. Yang D, Ding Y, Du T, Mao SH, Zhang ZJ (2018) Buoyant back-layering and the critical condition for preventing back-layering fluid in inclined tunnels under natural ventilation: brine water experiments. Exp Therm Fluid Sci 90:319–329

    Article  Google Scholar 

  25. Van Sommeren DDJA, Caulfield CP, Woods AW (2012) Turbulent buoyant convection from a maintained source of buoyancy in a narrow vertical tank. J Fluid Mech 701:278–303

    Article  MathSciNet  MATH  Google Scholar 

  26. Vantelon JP, Guelzim A, Quach D, Kim, Son D, Gobay D, Dallent D (1991) Investigation of fire-induced smoke movement in tunnels and stations: an application to the Paris Metro. In: proceedings of the third international symposium on fire safety science, Edinburgh, UK, Elsevier, Oxford, pp 907–918

Download references

Acknowledgements

The authors acknowledge support from the National Natural Science Foundation of China (NSFC) under Grant No. 51976017.

Author information

Authors and Affiliations

  1. School of Electric Power, Civil Engineering and Architecture, Shanxi University, Taiyuan, 030013, China

    Ping Li

  2. School of Civil Engineering, Chongqing University, Chongqing, 400045, China

    Ping Li & Dong Yang

Authors
  1. Ping Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Dong Yang
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Dong Yang.

Ethics declarations

Conflict of Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Li, P., Yang, D. Brine Water Experiments on Transient Flow and Evolution to Multiple States in Inclined Tunnel Fire with Forced Longitudinal Flow. Fire Technol 59, 743–765 (2023). https://doi.org/10.1007/s10694-022-01359-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10694-022-01359-3

Keywords

  • Transient evolution
  • Initial condition
  • Multiplicity
  • Inclined tunnel fire
  • Longitudinal ventilation