Ceiling jet

FIRE SIMULATOR predicts the effects of fire growth in a 1-room, 2-vent compartment with sprinkler and detector. It predicts temperature and smoke properties (Oj/CO/COj concentrations and optical densities), heat transfer through room walls and ceilings, sprinkler/heat and smoke detector activation time, heating history of sprinkler/heat detector links, smoke detector response, sprinkler activation, ceiling jet temperature and velocity history (at specified radius from the flre i, sprinkler suppression rate of fire, time to flashover, post-flashover burning rates and duration, doors and windows which open and close, forced ventilation, post-flashover ventilation-limited combustion, lower flammability limit, smoke emissivity, and generation rates of CO/CO, pro iri i post-flashover. 

Walton, W. D. and K. A. Notarianni, 1993, Comparison of Ceiling Jet Temperatures Measured in an Aircraft Hanger Test Fire with Temperatures Predicted by the DETACT-QS and LA VENT Computer Models, NIST, NISTIR 4947. 

The effect of ceiling beams and light fittings on ventilation jets was also studied by Holmes and Sachariewicz. Their studies were limited to the two-dimensional case air supply through linear slot and a two-dimensional barrier (Fig. 7.40). Tbe results of these studies show that the ceiling jet can take one of three courses when it encounters an obstruction ... 

Anderson, R., V. Hassani, A. Kirkpatrick, K. Knappmiller, and D. Hittle. 1991. Experimental and computational visualization of cold air ceiling jets. ASHRAE Journal, vol. 33, no. 5. 

The total rate of heat release in the room is assumed to come from five sources the gas burner, the vertical wall area behind the burner, a horizontal strip of material corresponding to the vertical height og the ceiling jet at the ceiling-wall intersection, the wall... 

For the geometry in Figure 12.7, the maximum temperature in the ceiling jet has been correlated by Alpert [15] ... 

Zukoski [16] has shown theoretical results that have stood the test of many experimental checks for the temperature and descent of a uniform smoke layer in a closed, but leaky (Ap 0), compartment. Similar to the scaling used for the ceiling jet, he found that... 

The saltwater, low-buoyancy system has a tendency to become laminar as the ceiling jet propagates away from the plume due to the buoyancy suppressing the turbulence. 

Figure 12.19 Fluorescent saltwater concentration distribution in a ceiling jet [27]...

Figure 12.20 shows the ceiling jet temperature distribution normalized by the maximum rise in the jet as a function of distance from the ceiling normalized with the jet thickness. The results apply to salt concentrations or temperature, and show that the distribution is independent of the distance from the plume. This saltwater analog technique is a powerful method for examining fire-induced flows, in particular with the technology demonstrated by Yao and Marshall [27]. 

Alpert, R. L., Turbulent ceiling-jet induced by large-scale fires, Combust. Sci. Technol., 1975, 11, 197-213. 

Yao, X. and Marshall, A. W., Characterizing Turbulent Ceiling Jet Dynamics with Salt-Water Modeling, Fire Safety Science-Proceedings of the Eighth International Symposium, Eds. Gottuk, G. T. and Lattimer, B. Y., pp. 927-938. 

The rate of heat release of a fire is the driving force for a buoyant plume. When the plume hits the ceiling, it turns into a ceiling jet whose characteristics determine when heat detectors respond4 or when sprinklers are activated.5... 

You, H.-Z. "An Investigation of Fire-Plume Impingement on a Horizontal Gelling 2—Impingement and Ceiling-Jet Regions." Fire Materials 9, no. L (1985) 46-56. 

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