Variation Characteristics of Reactive Plumes in the Process of Extinguishing Diesel Flame by Water Mist

Abstract

By using the three-dimensional governing equations of plumes, the cumulative volume fraction and the model of water suppress fire, the variation characteristics of the reactive plumes in the process of water mist suppress the diesel jet flame are studied. For the different effects of water mist and no water mist, the eddy structure of plume, averaged velocity and averaged temperature in the above of fire source are analyzed, respectively. It seems that there are expansibility and geometric symmetry for the eddy structure in the early stage of the water mist control. However, as a whole, the water mist has cooling effect for the plume area, and it can also reduce the spread velocity of plume. The large-scale structure can be formed quickly, and the temperature is affected by the droplet size and droplet density. However, for the case of no water mist, the bursting of smaller scale vortices can be enhanced, and its structural characteristic has an affect on the distribution of averaged temperature. Computational results have important significance for the water mist to be used in the ship engineer room.