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Fire-Induced Horizontal Vent Flow Pattern in a Ceiling Vented Enclosure: Theoretical Analysis and Experimental Verification

  • Xiao ChenEmail author
  • Shouxiang Lu
Conference paper

Abstract

The flow pattern is the one important factor to indicate the vented flow regularity, which is of great significance for understanding and preventing ceiling vented enclosure fires. In this paper, an experimental study on fire-induced flows in a ceiling vented enclosure was carried out. Five pan diameters and six horizontal opening sizes were adopted and measurements included the pressure difference in the top and temperature at the two sides of the opening. The instantaneous flow pattern was recorded by a video camera and laser technique. The purpose was to reveal the fire-induced flow pattern and make a distinguish between these flow patterns. Furthermore, the buoyancy number and the global equivalence ratio were introduced to analyze the fire-induced flow pattern in the ceiling vented enclosure. Through experimental analysis, the flow pattern across the horizontal ceiling vent induced by the real fire was revealed and summarized, which would benefit for studying the ventilation system in the fire risk assessment and firefighting.

Keywords

Ceiling vented enclosure Pool fire Flow pattern Buoyancy number 

Nomenclature

g

Gravity acceleration (m/s2)

t

Time (s)

vcb

Characteristic buoyancy-induced velocity (m/s)

A

Area (m2)

B

Buoyancy number (–)

D

Equivalent diameter of vent/pool (m)

Fr

Froude number (–)

Gr

Grashof number (–)

L

Vent thickness (m)

\(\Delta P\)

Pressure difference in the vent (Pa)

Re

Reynolds number (–)

T

Thermocouples (°C)

\(Y_{{{\text{o}}_{2} }}\)

Oxygen mass fraction in the enclosure

Greek symbols

\(\Delta \rho\)

Density difference in the vent (kg/m2)

\(\bar{\rho }\)

Average density (kg/m2)

\(\upsilon\)

Kinematic viscosity (m2/s)

\(\theta\)

Temperature ratio of ambient air and enclosure (–)

\(\phi\)

Global equivalence ratio (–)

\(\beta\)

Constant (–)

Subscripts

fuel(f)

Fuel

vent(v)

Horizontal vent

p

Pool fire

E

Extinction

Notes

Acknowledgements

The present work was supported by the National Natural Science Foundation of China (No. 51704268) and the China Postdoctoral Science Foundation (No. 2016M592068).

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Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

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

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