Repeatability assessment of large-scale fire experiment involving water spray system in a forced ventilated compartment

Hugues Pretrel (1) , Philippe Querre (1)

1 IRSN/PSN-RES/SA2I - Service des Agressions Internes et des risques Industriels

Repeatability of large scale fire test remains a key issue for code validation process. Most of the large scale experimental studies are based on single experiment and the influence of repeatability is barely considered in the test analysis process. Due to the substantial cost, reproducing several trials of a given large scale fire scenario is not often performed. In the framework of the OECD PRISME 2 project, this topic has been identified and a specific large scale fire test has been repro-duced twice in the final goal of assessing the level of repeatability. The scenario is an oil pool fire in a enclosure mechanically ventilated and during which a water spray system is activated. The analysis consists in identifying a set of variables on which metrics is applied in order to quantify the levels of discrepancy between the two tests. A set of 27 variables are selected such as they characterize the whole fire scenario (the fire source, the gas phase, walls, the ventilation network and the water spray system). The analysis points out that the repeatability levels are different depending on the type of variable. The gas temperature or species concentrations are more re-peatable than gas pressure or air flow rate. In addition, a new methodology is proposed in com-paring, for each physical variable, the variations due to repeatability (i.e. the precision) and the uncertainty. A new metric is proposed helping modelers in code validation process.

Mots clés: repeatability; uncertainty; large scale fire test; sprinkler; pool fire; ventilation; compartment

Domaines: Milieux fluides et réactifs

Hugues Pretrel, Philippe Querre. Repeatability assessment of large-scale fire experiment involving water spray system in a forced ventilated compartment. Fire and Materials, 2018, 43 (5), pp.436-447. ⟨10.1002/fam.2679⟩. ⟨irsn-04066580⟩