Vorticity distribution of spray jet with internal impingement

We use the particle image velocimeter (PIV) and Phase Doppler Particle Analyzer (PDPA) to measure the particle velocity of the spray flow field. The spray is injected by the atomizer designed with internal impinging mechanism. The spray distribution, gas entrainment, velocity vector and vorticity distribution of the spray flow fields with and without internal impingement are compared. Results show that the effect of the internal impingement results in higher gas entrainment and wider spray distribution as compared to the conventional ones. Furthermore, analysis on the instantaneous velocity diagram shows that the asymmetrical structure of the spray flow was attributed to the unsteady disturbance due to the internal impingement. This in turn enhances the mixing process of the liquid and gas phases in the spray flow. Measurement of vorticity and volume flux distributions confirmed the above observation.