Flow Through Horizontal Vents as Related to Compartment Fire Environments. September 29, 1990-September 30, 1991.
Flow Through Horizontal Vents as Related to Compartment
Fire Environments. September 29, 1990-September 30,
Tan, Q.; Jaluria, Y.
NIST GCR 92-607; 105 p. June 1992.
Sponsor:National Institute of Standards and Technology,
Available from: National Technical Information Service
Order number: PB92-213388
vents; compartment fires; convective flow; fire growth;
flow rate; room fires
A detailed investigation has been carried out on the
flow exchange through a horizontal vent in a compartment
containing a fire. A plexiglass tank with a vented
horizontal partition in the middle was constructed to
simulate the warmer interior environment due to a fire
and the cooler ambient environment by filling the upper
and lower compartment with brine and pure water,
respectively. Experiments have been carried out on the
combined natural and forced convection flow by imposing
a pressure difference across the vent. The flow rates
through the vent were determined over wide ranges of the
governing variables, such as the pressure difference
delta P across the opening, density difference delta rho
across the opening and the opening length to diameter
ratio L/D. The basic characteristics of the flow,
particularly whether it is unidirectional or
bidirectional, was also studied. Volume flow rates were
obtained as functions of the governing parameters in
terms of correlating equations, from which quantitative
information of the effect of delta P, delta rho and L/D
on the flow exchange through the vent can be determined.
These results can thus be applied to the modeling of
fire growth in vented rooms.