This study deals with the mixed convection flow through a shallow horizontal vent linking two compartments (one over the other). Depending on the temperature difference of gas as well as the ventilation flow rate between the two compartments, the flow through the vent can be bi- or uni-directional. A literature survey highlights that three correlations are used in safety engineering to calculate these upward and downward mixed convection flow rates. Unfortunately, for the same conditions, these correlations give very different results and, to date, there is no common agreement in the scientific community to identify quantitatively the most accurate model. This study proposes a new assessment of these correlations based on new experimental data obtained from the laboratory facility as well from the industrial apparatus. In addition, an improvement of the best model is proposed which better reproduced the experimental results.

References

1.
Cooper
,
L. Y.
,
1989
, “
Calculation of the Flow Through a Horizontal Ceiling/Floor Vent
,” National Institute of Standards and Technology, Gaithersburg, MD, Standard No. NISTIR 89-4052.
2.
Epstein
,
M.
,
1988
, “
Buoyancy Driven Exchange Flow Through Small Openings in Horizontal Partitions
,”
ASME J. Heat Transfer
,
110
(
4a
), pp.
885
893
.
3.
Tan
,
Q.
, and
Jaluria
,
Y.
,
1992
, “
Flow Through Horizontal Vents as Related to Compartment Fire Environments
,” National Institute of Standards and Technology, Gaithersburg, MD, Standard No. NIST-GCR-92-607.
4.
Li
,
Z.
,
2007
, “
Characteristics of Buoyancy Driven Natural Ventilation Through Horizontal Openings
,”
Ph.D. thesis
, Aalborg University, Aalborg, Denmark.http://vbn.aau.dk/en/publications/characteristics-of-buoyancy-driven-natural-ventilation-through-horizontal-openings(a2920120-4bdf-11dc-a457-000ea68e967b).html
5.
Varrall
,
K.
,
Pretrel
,
H.
,
Vaux
,
S.
, and
Vauquelin
,
O.
,
2016
, “
Stereoscopic Particle Image Velocimetry Investigation of the Bidirectional Natural Convection Flow Through a Horizontal Vent
,”
Fire Technol.
,
52
(
6
), pp.
2027
2041
.
6.
Mercer
,
A.
, and
Thompson
,
H.
,
1975
, “
An Experimental Investigation of Some Further Aspects of the Buoyancy-Driven Exchange Flow Between Carbon Dioxide and Air Following a Depressurization Accident in a Magnox Reactor, Part I: The Exchange Flow in Inclined Ducts—Part II: The Purging Flow Requirements in Inclined Ducts
,”
J. British Nucl. Energy Soc.
,
14
(4), pp.
327
340
.https://inis.iaea.org/search/search.aspx?orig_q=RN:7233965
7.
Epstein
,
M.
, and
Kenton
,
M. A.
,
1989
, “
Combined Natural Convection and Forced Flow Through Small Openings in a Horizontal Partition, With Special Reference to Flows in Multicompartment Enclosures
,”
ASME J. Heat Transfer
,
111
(
4
), pp.
980
987
.
8.
Cooper
,
L. Y.
,
1994
, “
Combined Buoyancy- and Pressure-Driven Flow Through a Horizontal Vent
,” National Institute of Standards and Technology, Gaithersburg, MD, Standard No. NISTIR 5384.
9.
Heskestad
,
G.
, and
Spalding
,
R. D.
,
1991
, “
Inflow of Air Required at Wall and Ceiling Apertures to Prevent Escape of Fire Smoke
,”
Third International Symposium on Fire Safety Science
, Scotland, UK, July 8–12, pp.
919
928
.
10.
Emmons
,
H. W.
, and
Tanaka
,
T.
,
2002
, “
Buoyant Flows Through Horizontal Vents
,”
SFPE Handbook of Fire Protection Engineering
,
P. J.
DiNenno
, ed., 4th ed.,
National Fire Protection Association Press
,
Quincy, MA
, pp.
2.44
2.45
.
11.
Tan
,
Q.
, and
Jaluria
,
Y.
,
2001
, “
Mass Flow Through a Horizontal Vent in an Enclosure Due to Pressure and Density Differences
,”
Int. J. Heat Mass Transfer
,
44
(
8
), pp.
1543
1553
.
12.
Le Quesne
,
M. A.
,
2010
, “
Saltwater Modelling of Fire Gas Flow Through a Horizontal Ceiling Opening
,”
Ph.D. thesis
, University of Canterbury, Canterbury, New Zealand.https://ir.canterbury.ac.nz/handle/10092/4304
13.
Chow
,
W. K.
, and
Li
,
J.
,
2011
, “
On the Bidirectional Flow Across an Atrium Ceiling Vent
,”
Building Environ.
,
46
(
12
), pp.
2598
2602
.
14.
Pretrel
,
H.
,
Sayada
,
R.
,
Varrall
,
K.
,
Audouin
,
L.
, and
Vauquelin
,
O.
,
2017
, “
Experimental Study Based on Large-Scale Smoke Propagation Fire Tests Through a Horizontal Opening Connecting Two Mechanically Ventilated Compartments
,”
Fire Saf. J.
,
90
, pp.
28
43
.
15.
Varrall
,
K.
,
Pretrel
,
H.
,
Vaux
,
S.
, and
Vauquelin
,
O.
,
2017
, “
Stereoscopic Particle Image Velocimetry Investigations of the Mixed Convection Exchange Flow Through a Horizontal Vent
,”
Exp. Fluids
,
58
, p. 151.
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