Effect of the Slot Number on the Breakup and Atomization of Liquid Film in Swirl Nozzle

doi:10.3901/JME.2021.04.247

Abstract

Abstract: The flow, breakup and atomization characteristics of conical liquid film under different injection pressures in a swirl nozzle are investigated with particle dynamic analyzer(PDA) and high-speed photographic system in this study. The effect of the liquid film’s velocity on its breakup and variation rule of spray quality parameters was analyzed under different injection pressure. The dispersion equation of the conical liquid film was solved by combining the corresponding experimental data, which verified the influence of the injection pressure on the breakup of liquid film. The increasing injection pressure will increase the nozzle flow rate and the droplet flow velocity, reduce the liquid film breakup length and the SMD(average diameter of Salter) in the spray field, the tangential velocity of liquid film has obvious effect on conical liquid film and make the spray angle firstly increasing and then stable. Under the same injection pressure, the film velocity, the droplet velocity, as well as the spray field concentration and uniformity are higher for the nozzle with larger swirl slot number, while the spray cone angle is smaller. The growth rate of liquid film surface waves was obtained by solving the dispersion equation, which proves that the increase of the swirl slot number raises the growth rate of liquid film surface waves, and finally decreases the breakup length of liquid film.

Key words: swirl nozzle, atomization, liquid film breakup, spray cone angle

CLC Number:

TG156

LIU Zhaomiao, LI Zexuan, LIN Jiayuan, PANG Yan. Effect of the Slot Number on the Breakup and Atomization of Liquid Film in Swirl Nozzle[J]. Journal of Mechanical Engineering, 2021, 57(4): 247-256.

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