A Numerical Model for Flow Simulation in Spray Nozzles

A commercial code called SIMULENT [1] is used to simulate liquid film formation and its breakup in an industrial spay nozzle. The model is three-dimensional and combines the solution of continuity and momentum equations with an algorithm for free surface tracking in presence of an arbitrary nozzle shape. Two types of spray nozzles were considered: a splash-plate atomizer and a swirling spray nozzle. The model predicts the liquid film characteristics of a nozzle as a function of its geometrical design, operating conditions, and fluid properties. The model simulates the process of the core liquid film breakup into ligaments and formation of small droplets from ligaments during the spray. The model has been proven accurate by direct comparison with experimental measurements. The developed computer software can be used as a tool to: (a) design new nozzles; (b) improve current nozzle designs; (c) provide the spraying characteristics of a nozzle, specifically: spray angle; spray pattern; mixing/swirling within the spray; mean droplet size; droplet size distribution; velocity of the droplets at a certain distance from the nozzle exit, etc., and (d) investigate the spraying characteristics of a nozzle under different operating conditions.