- Author
-
Jaluria, Y.
|
Goldman, D.
- Title
- Experimental Study of Negatively Buoyant Flows Generated in Enclosure Fires.
- Coporate
- Rutgers State Univ., New Brunswick, NJ
- Sponsor
- National Bureau of Standards, Gaithersburg, MD
- Report
-
NBS GCR 85-487,
February 1985,
52 p.
- Distribution
- AVAILABLE FROM National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161. Telephone: 1-800-553-6847 or 703-605-6000; Fax: 703-605-6900; Rush Service (Telephone Orders Only) 800-553-6847; Website: http://www.ntis.gov
- Contract
- NB83NADA4047
- Keywords
-
air flow
|
compartment fires
|
fire hazards
|
flow rate
|
penetration
|
room fires
|
smoke
- Abstract
- An experimental investigation of the nature of the velocity and thermal fields in negatively buoyant flows generated in enclosure fires is carried out. The flow congifuration considered is that of a negatively buoyant two-dimensional jet discahrged adjacent to a vertical surface, as well as that discharged away from the boundaries of the region. Such flows are frequently encountered in enclosures due to the downward turning of the flow induced by the fire plume, at the corners of the ceiling. Similarly, wall flows generated in the upper stably stratified region in room fires penetrate into the cooler, lower, region. In these cases, the buoyancy force is upward while the flow is downward, resulting in a negatively buoyant circumstance. An experimental system is developed to study the downward penetration of such jets in which the buoyancy force opposes the flow. The penetration distance is measured and related to the inflow conditions, particularly the temperature and velocity at the discharge location. A steady-state circumstance is simulated by allowing the fluid to flow out of the enclosure at the open top. The velocity and temperature distributrions are also measured, in order to understand the basic nature of these flows. Of particilar interest is the entrainment of the ambient fluid into the flow, since this is related to mixing and to mass and energy balance considerations in enclosure fires. Several other effects are also considered in this study.