Fire Technology

, Volume 52, Issue 6, pp 2093–2115 | Cite as

Large Eddy Simulations of the Ceiling Jet Induced by the Impingement of a Turbulent Air Plume

  • Setareh Ebrahim Zadeh
  • Georgios Maragkos
  • Tarek Beji
  • Bart Merci
Article

Abstract

In this paper, a sensitivity study is performed with FireFOAM 2.2.x for a hot air jet plume impinging onto a flat horizontal ceiling. The plume evolution and the induced ceiling flow are considered. The influence of the level of turbulence imposed at the inlet, in terms of intensity and eddy length scale, is discussed. Also, the effect of the turbulence model constant is examined. For the case considered, the best results are obtained when no sub-grid scale (SGS) model is used. If a SGS model is used, the level of turbulence at the inlet and the choice of the turbulence model constant are shown to have a significant effect on the prediction of plume’s spreading and the ceiling flow velocity. The eddy length scale at the inflow does not have significant impact on the results. Comparisons with the available experimental data indicate that FireFOAM is capable of predicting the mean velocity-field well. In the near field region, an under-estimation of the turbulent velocity fluctuations is observed, whereas reasonably good agreement is obtained in the far field.

Keywords

FireFOAM Hot air jet plume Ceiling flow LES 

List of Symbols

T

Temperature (°C)

Re

Reynolds number (–)

u

Velocity (m/s)

v

Velocity (m/s)

D

Diameter (m)

Fr

Froude number (–)

g

Gravitational acceleration (m/s2)

k

Turbulent kinetic energy (m2/s2)

p

Pressure (Pa)

Y

Mass fraction (–)

Dk

Molecular diffusivity (m2/s)

Dth

Thermal diffusivity (m2/s)

Pr

Prandtl number (–)

hs

Sensible enthalpy (J/kg)

ck

One-equation turbulence model constant (-)

cs

Smagorinsky model constant (–)

S

Strain rate (s−1)

z

Height (m)

r

Radial distance (m)

Greek

ρ

Density (kg/m3)

μ

Dynamic viscosity (kg/(m s))

ν

Kinematic viscosity (m2/s)

ε

Turbulent dissipation rate (m2/s3)

δv

Viscous sublayer (mm)

δij

Kronecker delta (–)

Subscripts

i

Inlet

m

Maximum

Ambient

t

Turbulent

Superscripts

Fluctuations

References

  1. 1.
    George WK, Alpert RL, Tamanini F (1977) Turbulence measurements in an axisymmetric buoyant plume, International J Heat Mass Transf 20:1145–1154CrossRefGoogle Scholar
  2. 2.
    Shabbir A, George WK (1994) Experiments on a round turbulent buoyant plume. J Fluid Mech 275:1–32CrossRefGoogle Scholar
  3. 3.
    Van Maele K, Merci B (2006) Application of two buoyancy-modified k–ε turbulence models to different types of buoyant plumes. Fire Saf J 41:122–138CrossRefGoogle Scholar
  4. 4.
    Zhou X, Luo KH, Williams JJR (2001) Large-eddy simulation of a turbulent forced plume. Eur J Mech B/Fluids 20:233–254CrossRefMATHGoogle Scholar
  5. 5.
    Worthy J, Rubini P (2005) A study of LES stress and flux models applied to a buoyant jet. Numer Heat Transf B Fundam 48:235–256CrossRefGoogle Scholar
  6. 6.
    Yan ZH (2007) Large eddy simulations of a turbulent thermal plume. Heat Mass Transf 43:503–514CrossRefGoogle Scholar
  7. 7.
    Maragkos G, Rauwoens P, Wang Y, Merci B (2013) Large eddy simulations of the flow in the near-field region of a turbulent buoyant helium plume. Flow Turbul Combust 90:511–543CrossRefGoogle Scholar
  8. 8.
    Xin Y, Gore J, McGrattan KB, Rehm RG, Baum HR (2002) Large eddy simulation of buoyant turbulent pool fires. Proc Combust Inst 29:259–266.CrossRefGoogle Scholar
  9. 9.
    Worthy J, Rubini P (2003) Large eddy simulation of buoyant plumes, 4th International Seminar on Fire and Explosion Hazards, Londonderry, UK.Google Scholar
  10. 10.
    Zhou X (2015) Characterization of interactions between hot air plumes and water sprays for sprinkler protection. Proc Combust Inst 35:2723–2729CrossRefGoogle Scholar
  11. 11.
    Zhou X (2015) PIV measurments of velocity fields of three hot air jet plumes impinging on a horizontal ceiling, 10th Asia-Oceania Symposium on Fire Science and Technology, Tsukuba, Japan.Google Scholar
  12. 12.
    Alpert RL (1975) Turbulent ceiling-jet induced by large-scale fires. Combust Sci Technol 11:197–213CrossRefGoogle Scholar
  13. 13.
    You HZ, Faeth GM (1981) An investigation of fire impingement on a horizontal ceiling, Pennsylvania State University, Department of Mechanical EngineeringGoogle Scholar
  14. 14.
    Kung H-C, You H-Z, Spaulding RD (1986) Ceiling flows of growing rack storage fires. Twenty first Symposium (International) on Combustion/The Combustion Institute, pp 121–128Google Scholar
  15. 15.
    Chatterjee P, Meredith KV, Ditch B, Yu H-Z, Wang YI, Tamanini F (2014) Numerical simulations of strong-plume driven ceiling flows. Fire Saf Sci 11:207–207CrossRefGoogle Scholar
  16. 16.
  17. 17.
    Drysdale D (2011) An introduction to fire dynamics. Wiley, New YorkCrossRefGoogle Scholar
  18. 18.
  19. 19.
    Schumann U (1975) Subgrid scale model for finite difference simulations of turbulent flows in plane channels and annuli. J Comput Phys 18:376–404MathSciNetCrossRefMATHGoogle Scholar
  20. 20.
    Yoshizawa A, Horiuti K (1985) A statistically-derived subgrid-scale kinetic energy model for the large-eddy simulation of turbulent flows. J Phys Soc Jpn 54:2834–2839.CrossRefGoogle Scholar
  21. 21.
    Fureby C, Tabor G (1997) Mathematical and physical constraints on large-eddy simulations. Theoret Comput Fluid Dyn 9:85–102MathSciNetCrossRefMATHGoogle Scholar
  22. 22.
    OpenFOAM: The Open Source CFD Toolbox, User Guide, version 2.3.0. February 05, 2014Google Scholar
  23. 23.
    Kornev N, Kröger H, Hassel E (2008) Synthesis of homogeneous anisotropic turbulent fields with prescribed second-order statistics by the random spots method. Commun Numer Methods Eng 24:875–877.MathSciNetCrossRefMATHGoogle Scholar
  24. 24.
    Sullivan PP, McWilliams JC, Moeng C-H, A subgrid-scale model for large-eddy simulation of planetary boundary-layer flows. Bound-Layer Meteorol 71:247–276CrossRefGoogle Scholar
  25. 25.
    Versteeg HK, Malalasekera W (2007) An introduction to computational fluid dynamics: the finite volume method. Pearson EducationGoogle Scholar
  26. 26.
    Pope SB (2000) Turbulent flows. Cambridge University Press, CambridgeCrossRefMATHGoogle Scholar
  27. 27.
    Alpert RL (2002) SFPE handbook of fire protection engineering, Ceiling jet flows. Springer, BerlinGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Setareh Ebrahim Zadeh
    • 1
  • Georgios Maragkos
    • 1
  • Tarek Beji
    • 1
  • Bart Merci
    • 1
  1. 1.Department of Flow, Heat and Combustion MechanicsGhent UniversityGhentBelgium

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