Field Model Analysis and Experimental Assessment of Fire Severity and Smoke Movement in a Partitioned and a Non-partitioned Dwelling Unit

Abstract

Inter-compartment smoke spread in a dwelling unit is greatly impeded by the presence of partition walls. For the same fire load and floor area, smoke movement and associated fire severity for a non-partitioned (NP) unit are different from those of a partitioned (PT) unit. To study the smoke movement and gas temperature evolution, computational fluid dynamics (CFD) analysis is carried out for a partitioned and a non-partitioned dwelling unit for the same fire load. The model predictions in terms of gas temperatures are then compared with the experimental measurements for both units. The gas temperatures inside the units are measured using K-type mineral insulated thermocouples, positioned at various elevations in the room of fire origin, and at other locations that were in the path of anticipated smoke movement. Also, to study the effectiveness of fire suppression methods, water spray and water mist methods are employed in the partitioned and non-partitioned units, respectively, when the fire reached decay stage.

Both computational and experimental investigations showed that for a fire occurring in a room with a floor area of 12.65 m² and a fire load of 1750 MJ within a total floor area of 90.4 m² of the dwelling unit, the peak temperature in the room of the fire origin of the partitioned unit is nearly 18% higher than that of the non-partitioned unit. Far-off locations from the fire source had higher CO concentration in the case of the non-partitioned unit, indicating faster smoke movement. Possible explanations for the deviations in measured and computed parameters are given. For fire suppression purpose, use of the conventional water spray system is found to be much quicker compared to the water mist system, albeit the water consumption is nearly 10 times higher. The analysis presented here serves as a useful reference or case study for fire safety engineers in assessing the smoke movement and fire severity with respect to the effectiveness of partition walls.

Keywords

fire modeling field models compartment fire experimental measurement fire severity smoke movement

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