EVALUATION OF THE EFFECT OF DROPLET COLLISIONS ON SPRAY MIXING

A spray model, implemented in a three-dimensional computational fluid dynamics (CFD) code has been used to evaluate the effect of droplet co llisions on splay mixing resulting from the overlapping of liquid spra y cones produced by two parallel hollow-cone nozzles under the influen ce of a cross-flow. The computations are compared with experimental re sults from phase Doppler anemometer (PDA) measurements in mixing stead y sprays. The results show that the droplet collisions, which mainly o ccur in the mixing area of the two different sprays, have great influe nce on the droplet size and, as a consequence, on the predicted drople t velocities, especially at distances far from the spray nozzles. Info rmation about the collision mechanisms as well as about droplet veloci ties and droplet dispersion due to collisions is also presented.