Thermal response of unconfined ceilings above growing fires and the importance of convective heat transfer

Experimental Study Of Heat Transfer To Ceiling From An Impinging Diffusion Flame

“…Most of the related work has dealt with jets of high Reynolds number, which result in such a high heat flux which are never found in connection with impinging flames or plumes of natural fires. Convective heat transfer from impinging plumes has been studied, e.g., by Alpert [1][2][3], by Zukoski et al [4,5], and by Cooper et al [6][7][8][9]. In the scale where ignition of combustible linings might be possible the work by You and Faeth [10][11][12][13] and that by Heskestad and Hamada [14] are very useful.…”

Test results and predictions for the response of near-ceiling sprinkler links in a full-scale compartment fire

“…The equation predicts the ceiling jet velocity distribution as a function of fire energy release rate, fire-toceiling spacing, distance from the fire plume -ceiling impingement point, and distance below the ceiling. ceiling surfaces [11][12][13]. Also, temperature distributions of ceiling surfaces [14][15][16] and throughout ceiling jets [e.g., [15][16][17][18][19] These upper layer effects have been modeled analytically [11,20,21] and they have been observed experimentally [16,18,22] Figure 4 and used below in the analysis of link response.…”

The Ceiling Jet In Fires

“…The basic equations then become (I_Ri)dO=O (4) dx Equation (4) indicates that the jet depth cannot change unless the Richardson Number equals 1, i.e., the stream velocity equals the shallow water surface wave speed u={?6…”

“…The heat transfer has been of major eoncem. [3,4] In a few cases, the ceiling jet in a corridor-sa simpler geornetry-vhas been studied. A full three-dimensional theory [5,6] shows the expected bulbous front of the transient jet which is well known from hydraulic experiments [7,8] but which is of little importance in fire spread.…”