Experimental analysis of the distribution of drops in the low pressure area generated by two spray

In order to obtain an appreciable effect of extinction of the heat from a heat source (eg a fire) it is necessary that the water flows are high (20- 30 liters per minute) and the droplet diameters are between 20 and 100 microns. To achieve both of these two features are the nozzles of the type used multi hole and supply pressures exceed 80 bar. In these conditions there are strong interactions between the individual holes that generate particular phenomena such as entrainment' s air and the generation of areas where the drops tend to stagnate. To understand the physics of this second phenomenon, in this paper the interaction of two spray is studied . It defines the regions of interaction between the two sprays and then these are characterized using a PDA system.