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Experimental Investigation on Lateral Temperature Profile of Window-Ejected Facade Fire Plume with Ambient Wind

  • Fei Ren
  • Longhua Hu
  • Xiepeng Sun
Article
  • 30 Downloads

Abstract

The present study investigated experimentally the lateral temperature profiles of window-ejected facade fire plume from compartment with external ambient wind normal to the facade. The previous reports only focused on no wind conditions that the entrainment and diffusion of ambient air with the fire plume, which determines this lateral temperature profiles, is controlled solely by the buoyancy of the plume itself. This could be essentially affected by the external ambient wind, however, has not been revealed or quantified in the past. Hence, in this work, reduced-scale experiments were carried out employing a cubic compartment with an opening (window) and a facade wall, subjected to ambient wind provide by a wind tunnel. The lateral temperature profiles of the fire plume issued through the compartment opening was measured by thermocouples arrays installed along the facade, for various opening dimensions and ambient wind speeds. Results showed that with increasing of wind speed, the temperature at a fixed position decreased gradually, especially at those positions near the facade; while the lateral decay of temperature at a given height was faster as the wind speed was higher. This was interpreted by the physics that the ambient wind normal to the facade enhanced the entrainment and diffusion of ambient fresh air into the plume. Then, a formula (based upon classic Gaussian function) was put forward to characterize the lateral temperature profiles of the facade fire plume, by using the modified effective characteristic plume thickness (a horizontal diffusion length scale) to include wind effect. The obtained data and proposed formula in the present study provide a basic understanding for the window-ejected facade fire plume characteristics with ambient wind.

Keywords

Window-ejected facade fire plume Lateral temperature profile Gaussian profile Urban fire Ambient wind 

List of Symbols

A

Opening area (m2)

\( A\sqrt H \)

Ventilation factor of compartment opening (m2.5)

g

Gravitational acceleration (m/s2)

H

Opening height (m)

K

The ratio of the characteristic size of the facade fire plume in the direction normal to the facade to that parallel to the facade (dimensionless)

Kw

The ratio of the characteristic size of the facade fire plume in the direction normal to the facade to that parallel to the facade with wind (dimensionless)

1

Characteristic length scale of assumed rectangular fire source (m)

2

Characteristic length scale of assumed rectangular fire source (m)

x

Characteristic size of facade fire plume in the direction normal to facade (m)

y

Characteristic size of facade fire plume in the direction parallel to facade (m)

L

Effective characteristic thickness of the facade fire plume (m)

Lw

Effective characteristic thickness of the facade fire plume with wind (m)

\( \dot{Q}^{*}_{ex} \)

Non-dimensional excess heat release rate (dimensionless)

Uw

Ambient wind speed (m/s)

W

Opening width (m)

x

Lateral distance away from the facade wall (m)

xm

Lateral horizontal coordinate of the maximum temperature (m)

z

Vertical height (m)

zn

Neutral plane height of the window (m)

z0

Virtual origin height (m)

Greek Symbols

α

Entrainment coefficient (dimensionless)

β

Gaussian profile constant (dimensionless)

ΔTx

Temperature rise above the ambient (°C)

ΔTmax

Maximum temperature rises above the ambient for a given height (°C)

λ

A coefficient to describe wind effect on air entrainment (dimensionless)

Notes

Acknowledgements

This work was supported by Key project of National Natural Science Foundation of China under Grant No. 51636008, NSFC-STINT joint Project (51811530015), Key Research Program of Frontier Sciences, Chinese Academy of Science (CAS) under Grant No. QYZDB-SSW-JSC029 and Fundamental Research Funds for the Central Universities under Grant Nos. WK2320000035 and WK2320000038.

References

  1. 1.
    Asimakopoulou EK, Kolaitis DI, Founti MA (2017) Assessment of fire engineering design correlations used to describe the geometry and thermal characteristics of externally venting flames. Fire Technol 53(2):709–739CrossRefGoogle Scholar
  2. 2.
    Oleszkiewicz I (1990) Fire exposure to exterior walls and flame spread on combustible cladding. Fire Technol 26(4):357–375CrossRefGoogle Scholar
  3. 3.
    Livkiss K, Svensson S, Husted B, Hees PV (2018) Flame heights and heat transfer in Façade system ventilation cavities. Fire Technol 54(3):689–713CrossRefGoogle Scholar
  4. 4.
    Yokoi S (1960) Study on the prevention of fire spread caused by hot upward current. In: Report of the Building Research Institute, Ministry of Construction, Japan, Report 34Google Scholar
  5. 5.
    Seigel LG (1969) The projection of flames from burning buildings. Fire Technol 5(1):43–51CrossRefGoogle Scholar
  6. 6.
    Thomas PH, Law M (1972) The projection of flames from buildings on fire. Fire Prev Sci Technol 10:19–26Google Scholar
  7. 7.
    Lassus J, Courty L, Garo JP, Studer E, Jourda P, Aine P (2014) Ventilation effects in confined and mechanically ventilated fires. Int J Therm Sci 75:87–94.CrossRefGoogle Scholar
  8. 8.
    Bøhm B, Rasmussen BM (1987) The development of a small-scale fire compartment in order to determine thermal exposure inside and outside buildings. Fire Saf J 12(2):103–108CrossRefGoogle Scholar
  9. 9.
    Hu LH, Hu KZ, Ren F, Sun XP (2017) Facade flame height ejected from an opening of fire compartment under external wind. Fire Saf J 92:151–158CrossRefGoogle Scholar
  10. 10.
    Tang F, Hu LH, Delichatsios MA, Lu KH, Zhu W (2012) Experimental study on flame height and temperature profile of buoyant window spill plume from an under-ventilated compartment fire. Int J Heat Mass Transf 55(1–3):93–101CrossRefGoogle Scholar
  11. 11.
    Ren F, Hu LH, Sun XP, Hu KZ (2018) An experimental study on vertical temperature profile of facade fire plume ejected from compartment with an opening subjected to external wind normal to facade. Int J Therm Sci 130:94–99CrossRefGoogle Scholar
  12. 12.
    Lee YP, Delichatsios MA, Silcock G (2007) Heat fluxes and flame heights in facades from fires in enclosures of varying geometry. Proc Combust Inst 31:2521–2528CrossRefGoogle Scholar
  13. 13.
    Tang F, Hu LH, Lu KH, Zhang XC, Shi Q (2015) Heat flux profile upon building facade due to ejected thermal plume from window in a sub-atmospheric pressure at high altitude. Energy Build 92:331–337CrossRefGoogle Scholar
  14. 14.
    Himoto K, Tsuchihashi T, Tanaka Y, Tanaka T (2009) Modeling thermal behaviors of window flame ejected from a fire compartment. Fire Saf J 44:230–240CrossRefGoogle Scholar
  15. 15.
    Yamaguchi JI, Tanaka T (2005) Temperature profiles of window jet plume. Fire Sci Technol 24(1):17–38CrossRefGoogle Scholar
  16. 16.
    Hu LH, Tang F, Delichatsios MA, Lu KH (2013) A mathematical model on lateral temperature profile of buoyant window spill plume from a compartment fire. Int J Heat Mass Transf 56(1):447–453CrossRefGoogle Scholar
  17. 17.
    McCaffrey BJ (1979) Purely buoyant diffusion flames: some experimental results. NBSIR 79-1910, National Bureau of Standards, Washington, DCGoogle Scholar
  18. 18.
    Baum HR, McCaffrey BJ (1989) Fire induced flow field-theory and experiment. Fire Saf Sci 2:129–148CrossRefGoogle Scholar
  19. 19.
    Alpert RL (1975) Turbulent ceiling-jet induced by large-scale fires. Combust Sci Technol 11:197–213CrossRefGoogle Scholar
  20. 20.
    Heskestad G (1983) Virtual origins of fire plumes. Fire Saf J 5:109–114CrossRefGoogle Scholar
  21. 21.
    Lee YP (2006) Heat fluxes and flame heights in external facade fires. Ph.D. thesis FireSERT, University of Ulster, BelfastGoogle Scholar
  22. 22.
    Bishop SR, Holborn PG, Drysdale DD (1995) Experimental comparison with a compartment fire model. Int Commun Heat Mass 22(2):235–240CrossRefGoogle Scholar
  23. 23.
    Hayashi Y, Ohmiya Y, Saga T (2003) Experimental study on fire and plume properties using BRI’s fire wind tunnel facility. Fire Sci Technol 22(1):17–35CrossRefGoogle Scholar
  24. 24.
    Quintiere JG (1989) Scaling applications in fire research. Fire Saf J 15(1):3–29CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.State Key Laboratory of Fire ScienceUniversity of Science and Technology of ChinaHefeiChina

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