Table Of ContentEnclosure Fire Dynamics
Enclosure Fire Dynamics
Second edition
Björn Karlsson
James G. Quintiere
Second edition prepared by Nils Johansson and Björn Karlsson
Second edition published 2022
by CRC Press
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First edition published by CRC Press 1999
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Library of Congress Cataloging-in-Publication Data
Names: Karlsson, Björn, author. | Quintiere, James G., author.
Title: Enclosure fire dynamics / Björn Karlsson, James G. Quintiere.
Description: Second edition. | Boca Raton, FL : CRC Press, 2022. |
Includes bibliographical references and index. |
Summary: “Enclosure fire dynamics, Second edition, explores the science of enclosure fires, and how they cause
changes in the environment of a building on fire. The authors discuss mechanisms controlling enclosure fires, and
how to develop analytical relationships useful in designing buildings for fire safety. Derivation of equations from first
principles is shown, stating assumptions and showing comparisons to experimental data, giving calculated examples
for clarity. The text provides readers with the skills needed to solve a range of engineering equations and problems.
Enclosure fire dynamics, Second edition will enhance the knowledge of fire protection engineers, researchers, and
investigators, and help build a strong foundation for engineering students”– Provided by publisher.
Identifiers: LCCN 2021061764 (print) | LCCN 2021061765 (ebook) |
ISBN 9781138058668 (hbk) | ISBN 9781032286464 (pbk) | ISBN 9781315163819 (ebk)
Subjects: LCSH: Enclosure fires.
Classification: LCC TH9195 .K37 2022 (print) | LCC TH9195 (ebook) |
DDC 693.8/2–dc23/eng/20220125
LC record available at https://lccn.loc.gov/2021061764
LC ebook record available at https://lccn.loc.gov/2021061765
ISBN: 978-1-138-05866-8 (hbk)
ISBN: 978-1-032-28646-4 (pbk)
ISBN: 978-1-315-16381-9 (ebk)
DOI: 10.1201/b22214
Typeset in Palatino
by codeMantra
Contents
List of Symbols .............................................................................................................................vii
Preface ..............................................................................................................................................xi
Acknowledgments ......................................................................................................................xiii
Authors ...........................................................................................................................................xv
1. Introduction .............................................................................................................................1
2. A Qualitative Description of Enclosure Fires.................................................................21
3. Energy Release Rates ...........................................................................................................41
4. Fire Plumes and Flame Heights .........................................................................................69
5. Pressure Profiles and Vent Flows for Well-Ventilated Enclosures ...........................111
6. Gas Temperatures in Ventilated Enclosure Fires .........................................................155
7. Heat Transfer in Compartment Fires ..............................................................................193
8. Conservation Equations and Smoke Filling .................................................................235
9. Combustion Products ........................................................................................................283
10. Computer Modeling of Enclosure Fires .........................................................................313
Appendix A: Suggestions for Experiments and Computer Labs .....................................339
Appendix B: Fire Safety Engineering Resources on the Internet ....................................349
Index .............................................................................................................................................359
v
List of Symbols
A Area (m2)
A Area of ceiling vent (m2)
c
A Area of opening for in-flowing gases (Chapter 8) (m2)
D
A Area of opening for out-flowing gases (Chapter 8) (m2)
E
A Horizontal burning area of fuel (m2)
f
A Area of lower opening (Chapter 5) (m2)
l
A Area of opening (Chapter 6) (m2)
o
A Total surface area bounding an enclosure (m2)
t
A Total internal enclosure surface area (minus opening area) (m2)
T
A Area of upper opening (Chapter 5) (m2)
u
A Enclosure surface area in contact with hot gases (Chapter 8) (m2)
w
b Plume radius (m)
c Specific heat (Chapter 6) (kJ/(kg K))
c Specific heat at constant pressure (kJ/(kg K))
p
c Specific heat at constant volume (kJ/(kg K))
v
C Correction factor for mean beam length (Chapter 7) (−)
C Constant for visibility calculation (Chapter 9) (−)
C Flow coefficient (-)
d
C Constant in ideal plume equations (−)
1
C Constant in ideal plume equations (m4/3/s)
2
D Diameter (m)
D Dimensionless height to smoke layer (Chapter 5) (−)
e Specific total energy (Chapter 8) (J/kg)
E Total energy (Chapter 8) (J)
E Emissive power (Chapter 7) (W/m2)
E Black-body emissive power (Chapter 7) (W/m2)
b
f Fuel mixture fraction (Chapter 9) (−)
F Force (N)
F Configuration factor (Chapter 7) (−)
Fr Froude number (−)
g Acceleration due to gravity (m/s2)
G Irradiance (Chapter 7) (W/m2)
h Specific enthalpy (Chapter 8) (J/kg)
h Height (m)
h Total heat transfer coefficient (W/(m2K))
h Convective heat transfer coefficient (W/(m2K))
c
h Effective heat conduction coefficient (W/(m2K))
k
h Height from neutral layer to center of lower opening (Chapter 3) (m)
l
h Height from neutral layer to center of upper opening (Chapter 3) (m)
u
H Enthalpy (Chapter 8) (J)
H Height between centerlines of two openings (Chapter 5) (m)
H Height of smoke layer from some reference point (m)
D
H Height of neutral layer from some reference point (m)
N
H Height of opening (m)
o
vii
viii List of Symbols
I Radiative intensity (Chapter 7) (W/m2)
I Black-body radiative intensity (Chapter 7) (W/m2)
b
J Radiosity (Chapter 7) (W/m2)
k Thermal conductivity (W/(mK))
kβ Material constant for liquid fuels (Chapter 3) (m−1)
K Multiplying factor (Chapter 6) (−)
f
K Light extinction coefficient (Chapter 9) (m−1)
K Mass-specific extinction coefficient (Chapter 9) (m2/kg)
m
L Length (m)
L Flame height (Chapter 4) (m)
L Flame height (Chapter 7) (m)
f
L Geometric mean beam length (Chapter 7) (m)
0
L Mean beam length (Chapter 7) (m)
m
m Mass (kg)
m Mass flow rate or mass burning rate (kg/s)
m Mass flow rate of ambient air (kg/s)
a
m Mass burning rate (kg/s)
b
m Mass flow rate of hot gases through a ceiling vent (kg/s)
c
m Mass flow rate of air in through an opening (Chapter 8) (kg/s)
d
m Mass flow rate of gases exiting from an opening (kg/s)
e
m Mass flow rate of hot gases (kg/s)
g
m Fan mass flow rate (Chapter 8) (kg/s)
o
m Plume mass flow rate (kg/s)
p
m′′ Mass flow rate of fuel (kg/(s m2))
m′′ Fuel burning rate for a large diameter (kg/(s m2))
f
M Molecular mass (kg/mol)
n Fire growth rate exponent (Chapter 8) (−)
N Dimensionless height to neutral layer (Chapter 5) (−)
Nu Nusselt Number (Chapter 7) (−)
P Pressure (Pa, N/m2)
P Ambient pressure (Chapter 8) (Pa, N/m2)
a
P Ambient pressure (Chapter 5) (Pa, N/m2)
0
Pr Prandtl Number (Chapter 7) (−)
q Heat (kJ)
q Heat flow rate (kW)
q Rate of heat storage in the gas volume (Chapter 6) (kW)
B
q Rate of heat lost to compartment boundaries (kW)
loss
q Rate of heat lost due to replacement of hot gases by cold (Chapter 6) (kW)
L
q′′ Radiative heat flux (kW/m2)
r
q Rate of heat lost by radiation through openings (Chapter 6) (kW)
R
q Rate of heat lost to compartment boundaries (Chapter 6) (kW)
w
q′′ Heat flux, or heat flow rate per unit area (kW/m2)
q′′ Convective heat flux (kW/m2)
c
Q Energy (kJ)
Q Fire load (Chapter 6) (kJ)
Q′′ Fire load density (Chapter 6) (kJ/m2)
Q′′ Fire load density per unit floor area of enclosure (Chapter 6) (kJ/m2)
f
Q′′ Fire load density per total enclosure surface area (Chapter 6) (kJ/m2)
t
Q Energy release rate (kW)
Q′′ Energy release rate per unit area (Chapter 3) (kW/m2)
List of Symbols ix
Q Convective part of energy release rate (kW)
c
Q Chemical energy release rate (Chapter 8) (kW)
ch
Q Energy release rate sufficient to cause flashover (kW)
FO
Q Maximum energy release rate (kW)
max
Q∗ Dimensionless energy release rate (−)
r Stoichiometric fuel to oxygen ratio (−)
r Radial flame extension under a ceiling (m)
f
R Gas constant for air (J/(kg K))
R Distance (Chapter 7) (m)
Ra Rayleigh Number (Chapter 7) (−)
R Universal Gas Constant (J/(mol K))
0
R Distance (Chapter 7) (m)
0
S Floor area (Chapter 8) (m2)
S Visibility (Chapter 9) (m)
t Time (s)
t∗ Dimensionless time (Chapter 4) (−)
2
(t∗) Dimensionless gas travel delay time (Chapter 4) (s)
2
f
t Starting time (Chapter 3) (s)
0
t Thermal penetration time (s)
p
t Duration of the steady phase of the fire (Chapter 3) (s)
s
T Temperature (°C or K)
T Ambient air temperature (°C or K)
a
T Temperature of gases exiting an enclosure (Chapter 8) (°C or K)
e
T Film temperature (Chapter 7) (°C or K)
f
T Temperature of hot gases (°C or K)
g
T Maximum ceiling jet temperature (°C or K)
max
T Centerline plume temperature (°C or K)
0
T Ambient air temperature (°C or K)
∞
u Specific internal energy (Chapter 8) (J/kg)
u Velocity (m/s)
u Critical velocity in tunnels (Chapter 6) (m/s)
c
u∗ Dimensionless critical velocity in tunnels (Chapter 6) (m/s)
c
u Maximum ceiling jet velocity (m/s)
max
u Centerline plume velocity (m/s)
0
U Internal energy (Chapter 8) (J)
v Velocity (m/s)
v Velocity of ambient gases (m/s)
a
v Velocity of hot gases through a ceiling vent (m/s)
c
v Velocity of hot gases (m/s)
g
V Volume (m3)
V′ Dimensionless ventilation volume (Chapter 6) (−)
V Volumetric flow rate (m3/s)
W Width of opening (m)
W Width of spill plume at balcony edge (Chapter 4) (m)
W Work done (Chapter 8) (J)
W Rate of work done (W)
X Dimensionless variable (Chapter 6) (−)
1
X Dimensionless variable (Chapter 6) (−)
2
