Experimental and numerical analysis of fire scenarios involving two mechanically ventilated compartments connected together with a horizontal vent

Hugues Pretrel (1) , Samuel Vaux (1)

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

This work deals with an experimental and numerical investigation of fire scenario involving two rooms mechanically ventilated and connected together with a horizontal vent. The objective is to investigate the effect of a horizontal opening on a fire scenario and especially on the burning rate. The study is based on the analysis of a set of large scale fire experiments performed in the framework of the OECD PRISME-2 project in the DIVA multi-room facility of the Institut de Ra-dioprotection et de Sûreté Nucléaire (IRSN), and of numerical simulations performed with the ISIS CFD code developed by IRSN. The fire scenario consists of two rooms, one above the other, mechanically ventilated, and connected to each other with a horizontal vent of 1 m2. The fire is heptane pool fire located in the lower room. The analysis focuses on the coupling between the burning rate, the flow at the vent and the configuration of the mechanical ventilation. Several regimes of combustion are encountered from well ventilated steady fire to under-ventilated un-steady and oscillatory fire. The results show that the burning rate is controlled by both the me-chanical ventilation and the downward flow from the vent. The numerical simulations highlight the specific pattern of the oxygen concentration field induced by the downward flow at the vent.

Mots clés: fire; horizontal opening; vent; under-ventilation; compartment

Domaines: Milieux fluides et réactifs

Hugues Pretrel, Samuel Vaux. Experimental and numerical analysis of fire scenarios involving two mechanically ventilated compartments connected together with a horizontal vent. Fire and Materials, 2019, 43 (5), pp.514-529. ⟨10.1002/fam.2695⟩. ⟨irsn-04066497⟩