- Author
-
Motevalli, V.
|
Marks, C. H.
- Title
- Transient Characteristics of Unconfined Fire-Plume-Driven Ceiling Jets. Final Report. 1986-1989.
- Coporate
- Worcester Polytechnic Institute, MA
Maryland Univ., College Park
- Sponsor
- National Bureau of Standards, Gaithersburg, MD
- Report
-
NIST GCR 90-574,
May 1990,
328 p.
- Distribution
- Available from National Technical Information Service
- Contract
- NIST-GRANT-70NANB5H0551
- Keywords
-
ceiling jets
|
fire plumes
|
fire tests
|
velocity measurement
|
cross correlation
- Abstract
- An extensive study of small-scale, unconfined, fire-induced ceiling jets was conducted under ceiling transient and steady state conditions. Constant, steady fire strengths of between 0.5 to 2.0 kW and fire-to-ceiling heights of 1.0 m and 0.5 m were used producing non-dimensional convective heat input to the ceiling, in the range of 4.5 x 10(-4) to 1.0 x 10(-2). The ceiling jet transient characteristics caused by the ceiling heating, as well as its steady state characteristics, were studied using velocity and temperature measurements. Detailed velocity and temperature measurements of the ceiling jet were made simultaneously using the cross-correlation velocimetry technique from the start of the fire until the ceiling reached steady state. Velocity and temperature profiles were obtained at several radial locations away from the plume impingement point. These measurements were made for transient and steady ceiling jet conditions in the case of the H=1.0 m. All the transient measurements in the H=0.5 m case were limited to temperature measurements. At steady state, however, both temperature and velocity measurements were obtained.