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Vent Flows

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Book cover SFPE Handbook of Fire Protection Engineering

Abstract

Fire releases a great amount of heat that causes the heated gas to expand. The expansion produced by a fire in a room drives some of the gas out of the room. Any opening through which gas can flow out of the fire room is called a vent.

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Notes

  1. 1.

    Equation 15.23 should be written u = (sign Δp)K \( \sqrt{\mathrm{T}\left|\Delta p\right|} \) since when Δ p  < 0 the absolute value must be used to avoid the square root of a negative number and the sign of the velocity changes since the flow is in and not out.

  2. 2.

    Sometimes the mean temperatures, \( \overline{T} \) of the two-layer model and the real flow are also used and both h n and T u are determined (using T d as above). The requirement of identical \( \overline{T} \) is arbitrary, sometimes leads to impractical results, and is not recommended.

References

  1. H. Rouse, Fluid Mechanics for Hydraulic Engineers, McGraw-Hill, New York (1938).

    Google Scholar 

  2. Mark’s Mechanical Engineers Handbook, McGraw-Hill, New York (1958).

    Google Scholar 

  3. J.S. Newman and P.A. Croce, Serial No. 21011.4, Factory Mutual Research Corp., Norwood, MA (1985).

    Google Scholar 

  4. D.J. McCaffrey and G. Heskestad, “Robust Bidirectional Low-Velocity Probe for Flame and Fire Application—Brief Communications,” Combustion and Flame, 26, pp. 125–127 (1976).

    Article  Google Scholar 

  5. J. Prahl and H.W. Emmons, “Fire Induced Flow Through an Opening,” Combustion and Flame, 25, pp. 369–385 (1975).

    Article  Google Scholar 

  6. K.D. Steckler, H.R. Baum, and J. Quintiere, 20th Symposium on Combustion, Pittsburgh, PA (1984).

    Google Scholar 

  7. J. Quintiere and K. DenBraven, NBSIR 78–1512, National Bureau of Standards, Washington, DC (1978).

    Google Scholar 

  8. H.E. Mitler and H.W. Emmons, NBS-GCR-81-344, National Bureau of Standards, Washington, DC (1981).

    Google Scholar 

  9. M. Epstein, “Buoyancy-driven exchange flow through small openings in horizontal partition, with special reference to flows in multicompartment enclosures”, Journal of Heat Transfer, 110, pp.885–893 (1988)

    Google Scholar 

  10. Q. Tan and Y. Jaluria, NIST-G&R-92-607, National Institute of Standards and Technology, Gaithersburg, MD (1992).

    Google Scholar 

  11. Heiselberg, P. and Li, Z., (2007), "Experimental study of buoyancy driven natural ventilation through horizontal openings", Proceedings of Roomvent 2007 : Helsinki 13–15 June 2007..

    Google Scholar 

  12. M. Epstein and M.A. Kenton, “Combined Natural Convection and Forced Flow Through Small Openings in a Horizontal Partition, with Special Reference to Flows in Multicompartment Enclosures,” Journal of Heat Transfer, 111, pp. 980–987 (1989).

    Article  Google Scholar 

  13. G. Heskestad and R. D. Spaulding, “Inflow of air required at wall and ceiling apertures to prevent escape of fire smoke”, Proceeding of the 3rd International Symposium on Fire Safety Science, pp.919–928 (1991)

    Google Scholar 

  14. L. Y. Cooper, “Combined buoyancy- and pressure-driven flow through a shallow, horizontal, circular vent”, HTD-Vol. 299, Heat Transfer With Combined Modes, ASME, Chicago (1994).

    Google Scholar 

  15. T. Tanaka, “A Model of Multiroom Fire Spread,” Fire Science and Technology, 3, p. 105 (1983).

    Article  Google Scholar 

  16. S. Yamada and T. Tanaka, “Reduced Scale Experiments for Convective Heat Transfer in the Early Stage of Fires,” International Journal on Engineering Performance-Based Codes, 1, 3, pp. 196–203 (1999).

    Google Scholar 

  17. T. Tanaka and T. Yamana, “Smoke Control in Large Scale Spaces (Part 1, Analytic theories for simple smoke control problems),” Fire Science and Technology, 5, 1, pp. 31–40 (1985).

    Article  Google Scholar 

  18. T. Tanaka, “Performance-Based Fire Safety Design Standards and FSE Tools for Compliance Verification,” International Journal on Engineering Performance-Based Codes, 1, 3, pp. 104–117 (1999).

    Google Scholar 

  19. B.J. McCaffrey, J.G. Quintiere, and M.F. Herkeleroad, “Estimating Room Temperature and Likelihood of Flashover Using Fire Test Data Corrections,” Fire Technology, 17, 2, pp. 98–119 (1981).

    Article  Google Scholar 

  20. T. Tanaka and K. Nakamura, “A Model for Predicting Smoke Transport in Buildings,” Report of the Building Research Institute, No. 123, Ministry of Construction, Tsukuba, Japan (1989).

    Google Scholar 

  21. T. Tanaka and S. Yamada, “BRI2002: Two Layer Zone Smoke Transport Model,” Fire Science and Technology, 23, Special Issue (2004).

    Google Scholar 

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Author information

Authors and Affiliations

  1. Fire Science and Technology, Kyoto University, Kyoto, Japan

    Takeyoshi Tanaka

Authors
  1. Takeyoshi Tanaka
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Editor information

Editors and Affiliations

  1. Aon Fire Protection Engineering, Greenbelt, MD, USA

    Morgan J. Hurley P.E., FSFPE (Editor-in-Chief) (Editor-in-Chief)

  2. Hughes Associates, Baltimore, USA

    Daniel Gottuk Ph.D., P.E.

  3. National Fire Protection Association, Quincy, USA

    John R. Hall Jr. Ph.D.

  4. Kyoto University, Kyoto, Japan

    Kazunori Harada Dr. Eng.

  5. National Institute of Standards and Technology, Gaithersburg, USA

    Erica Kuligowski Ph.D.

  6. Worcester Polytechnic Institute, Worcester, USA

    Milosh Puchovsky P.E., FSFPE

  7. The University of Queensland, St Lucia, Australia

    José Torero Ph.D.

  8. The Fire Safety Institute, Quincy, USA

    John M. Watts Jr. Ph.D., FSFPE

  9. FM Global, Johnston, USA

    Christopher Wieczorek Ph.D.

Nomenclature and Subscripts

A

Area (m2)

a

Length (m)

b

Width (m)

C

Flow coefficient (−)

c p

Specific heat at constant pressure (kJ/kg K)

c v

Specific heat at constant volume (kJ/kg K)

D

Orifice diameter (m)

Fr

Froude number (−)

g

Gravity constant (m/s2)

Gr

Grashof number (−)

h

Height (m)

[J]

Jacobian matrix

L

Orifice length (m)

M

Molecular weight (kg/kg mol)

ṁ

Mass flow rate (kg/s)

P

Perimeter (m)

p

Pressure (Pa)

\( \dot{Q} \)

Heat release rate of fire source (kW)

\( \dot{Q}{}_h \)

Heat loss by heat transfer (kW)

R

Gas constant (J/kg mol K)

Re

Reynolds number (−)

T

Temperature (K)

u

Velocity (m/s)

V

Volume (m3)

\( \dot{V} \)

Volume flow rate (m3/s)

V R

Room volume (m3)

y

Vertical coordinate (m)

α K

Effective heat transfer coefficient (kW/m2K)

Δ

Increment of

δ

Depth (see Fig. 15.6) (m)

γ = c p /c v

Isentropic exponent (−)

Π

Non-dimensional pressure (−)

ρ

Density (kg/m3)

μ

Viscosity (Ns/m2)

a

Atmosphere

b

Sill of vent

c

Ceiling of room

d

Lower

f

Floor

g

Gauge

i

Hot-cold interface

ij

From room (layer) i to room (layer) j

j

Index of layer

L, l

Lower

n

Neutral axis

O2

Oxygen

t

Soffit of vent

u, U

Upper

v, V

Vent, in the vent

0

Reference height

1

Upstream of orifice

2

Downstream of orifice

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© 2016 Society of Fire Protection Engineers

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Tanaka, T. (2016). Vent Flows. In: Hurley, M.J., et al. SFPE Handbook of Fire Protection Engineering. Springer, New York, NY. https://doi.org/10.1007/978-1-4939-2565-0_15

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  • DOI: https://doi.org/10.1007/978-1-4939-2565-0_15

  • Publisher Name: Springer, New York, NY

  • Print ISBN: 978-1-4939-2564-3

  • Online ISBN: 978-1-4939-2565-0

  • eBook Packages: EngineeringEngineering (R0)

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