An Experimental Study of Upper Hot Layer Stratification in Full-Scale Multiroom Fire Scenarios

Abstract

This paper describes an experimental study of the dynamics of smoke filling in realistic, full-scale, multiroom fire scenarios. A major objective of the study was to generate an experimental data base for use in the verification of mathematical fire simulation models. The test space involved 2 or 3 rooms, connected by open doorways. During the course of the study the areas were partitioned to yield four different configurations. One of the rooms was a burn room containing a methane burner which produced either a constant energy release rate of 25, 100, or 225 kW or a time-varying energy release rate which increased linearly with time from zero at ignition to 300 kW in 10 min. An artificial smoke source near the ceiling of the burn room provided a means for visualizing the descent of the hot layer and the dynamics of the smoke filling process in the various spaces. The development of the hot stratified layers in the various spaces was monitored by vertical arrays of thermocouples and photometers. A layer interface was identified and its position as a function of time was determined. An analysis and discussion of these results are presented.

Fire Experiments and Simulations in a Full-scale Atrium Under Transient and Asymmetric Venting Conditions

“…-Wall A. Twelve thermocouples were installed in three thermocouple trees to measure the temperature at 30 cm from the wall A (sensors [14][15][16][17][18][19][20][21][22][23][24][25] as can be observed in Figure 2c. These measurements are used to study the smoke temperature at the far field and the smoke layer drop.…”

“…It is usually evaluated in the literature by means of CO 2 concentration [16,17] as well as temperature measurements [18][19][20][21][22], the latter being the most used due to the ease of its measurement. There are many different temperature methods to evaluate the smoke layer interface in the literature, such as the n-percent method proposed by Cooper et al [18], the upper zone averaging and mass equivalency by Quintere et al [19], the maximum gradient method by Emmons [20], the Janssen method [21] or the least-square method by He et al [22]. All these methods, except the least-square method, present a certain grade of empiricism, because of that the least-square method has been used in this paper to compare the smoke layer interface both numerically and experimentally.…”

An experimental data set for the accuracy assessment of room fire models

“…With these measurements, Huggett [23] and Parker [24] detail a method to determine the rate of energy production of the fire based upon oxygen consumption calorimetry. used to calculate the mass flow in and out the first room doorway using the following equations: [18] l+At (2) where: Similarly, air temperatures from trees 5, 7, and 8 were used to ascertain the mass flow through the doorway to the third room and trees 5 and 6 were used to determine flow through the second room exit doorway. Table 8 presents average mass flows through the doorways during the main burn period (from main burner ignition to main burner extinguishment).…”

“…In the first category are the study of Alpert et al [1]* for a single room connected to a short, open corridor, and that of Cooper et al [2] for gas burner fires in a room-corridor-room configuration. The second category is large, but the works of Quintiere and McCaffrey [3], and Heskestad and Hill [4] are particularly detailed.…”

On the fluid dynamics of the make-up inlet air and the prediction of anomalous fire dynamics in a large-scale facility

“…The experimental data are compared with the numerical simulations for both domains and for all the sensors of Figure 1 b, that is, the centreline temperature (ideally the plume), the smoke through the fans temperature, the air close to walls temperature and the make-up air inlet velocity at the vents. In addition, by means of the N -percent method [10,11,15,29], the smoke layer height has been also considered. Measurements -time evolutions at different locations are presented for test #1, in table 2, and test #2, in table 3.…”