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Unsteady Three-Layer Fluid Model for Smoke Movement Prediction

  • Keichi SuzukiEmail author
Conference paper

Abstract

This paper describes a new method for modeling smoke movement within large rooms. The model includes horizontally two-dimensional and three laminar flows including the ceiling jet, reversed flow, and airflow. This model is practical because it can predict three-dimensional temperature distributions of any points in the volume simulations in a short time. For simple validation, predictions delivered by the model are compared to the measurements from fire experiments in a large building. The predicted gas temperature profiles agree qualitatively with the measurement, and then the performance of the model is generally acceptable.

Keywords

Modeling Compartment fires Ceiling jet Reversed flow 3-layer 

Nomenclature

.

cp

Specific heat of air (kJ/kg K)

g

Gravitation acceleration (m2/s)

h

Depth of layer (m)

H

Ceiling height from fire source (m)

P

Pressure (Pa)

q

Heat loss to ceiling (kW/m2)

t

Time (s)

ΔT

Gas temperature rise (K)

u

Velocity of the x-axis (m/s)

v

Velocity of the y-axis (m/s)

v0

Horizontal velocity at edge of plume near ceiling (m/s)

w

Vertical velocity in fire plume (m/s)

x

Horizontal coordinate (m)

y

Horizontal coordinate (m)

z

Vertical coordinate (m)

Greek Symbols

β

Buoyancy factor (=1/T)

γ

Ceiling jet profile factor (=1.16)

τw

Wall shear stress (kgf/m2)

ρ

Gas density (kg/m3)

Subscripts

max

Maximum value in vertical profile

u

Ceiling jet

m

Reversed flow

l

Air layer

Ambient

0

Initial value of ceiling jet

p

Plume

References

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Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.Institute of Technology Shimizu CorporationTokyoJapan

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