Abstract：To improve the spray effect of nozzle, the self-excited oscillation jet theory and pressure nozzle atomization were combined, the numerical model of the self-excited oscillation jet nozzle was established,and the effect of coulomb coefficient and jet pressure on the internal flow field and atomizing was studied using Fluent. The results show that the nozzle inclined wall design makes liquid rebound and oscillation phenomena occur, the original primary vortex ring in the nozzle jet exit,then gradually spread to all around, and drive to the whole inside the nozzle. With the increasing of body cavity coefficient, the velocity peak parabolic trend of first increases and then decreases, and the change rule of atomized particle size instead, which determines the best coefficient of body cavity range from 0.6 to 1.2, and jet pressure from 3 to 5 MPa.

Keywords: nozzle atomizing; self-excited oscillation; velocity distribution; numerical simulation