Thermodynamic characterization on the suppression process of water mist under the interaction effect between two buoyant non-premixed flames

[Display omitted] •Thermodynamic characteristics of the water mist on the double flames are explored.•The dynamic effect of water mist dominates rather than the cooling effect.•The cooling effect is affected by the droplet distribution to the layout of flames.•The scale effect in the suppression model of the double flames is verified. Realistic fire disaster scenarios always refer to multiple fires burning at adjacent positions at the same time (MF), leading to a higher risk compared with a single fire (SF). That is, fire suppression in realistic fire disasters differs from existing fire suppression studies focusing on a single flame. It is worthy to extend the fire suppression study to multiple fires. This study investigates the thermodynamic characteristics of applying the water mist on the double flames through FDS (Fire Dynamic Simulator v. 6.9.1). The fire suppression mechanism is discussed from two aspects (the cooling effect and the dynamic effect). The cooling effect of the water mist on the double flames is revealed based on the onset time of cooling. The droplet distribution is considered the main factor in the cooling effect of the water mist on the double flames (DF). The dynamic effect dominates in the two effects of the water mist. It is found that the interaction effect between double flames significantly improves the difficulty of penetrating the combustion area. This study can provide numerical data support and theoretical reference for water mist fire suppression systems applied in realistic scenarios.