Abstract:In this paper, an atomizer with laval nozzle is designed and studied by commercial CFD software. The influence of the five main factors (the atomization pressure P, the gas temperature T, the gas nozzle distance D, the gas injection angle α and the protrusion of delivery tube h) on the flow field structure is investigated. The result shows that the flow field structure of the laval nozzle is different from the annular nozzle without dramatic gas expansion and recirculation flow formed at the nozzle exit. The flow field velocity increases with atomization pressure, however, the static pressure (Ps) in recirculation zone remains unchanged. Along with the increase of gas temperature, the velocity and temperature in the flow field also increase. The gas nozzle distance affects the flow field velocity and Ps significantly. On the other hand, The flow field velocity and Ps increase with the gas injection angle. With the increasing of the conduct tube extension, the Ps declines before it rises.