Numerical Study on Primary Breakup of Disturbed Liquid Jet Sprays Using a VOF Model and LES Method

Processes

Ziming Li¹  Jiechang Wu¹  Zhenming Liu¹  Jingbin Liu¹  Yusong Yu²  Jiawei Ding³ 

[1] College of Power Engineering, Naval University of Engineering, Wuhan 430033, China;Hydrogen Energy and Space Propulsion Laboratory (HESPL), School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China;Xi’an Aerospace Propulsion Test Technique Institute, Xi’an 710100, China;

关键词: volume of fluid (VOF);    large-eddy simulation (LES);    spray;    primary breakup;    surface wave;    ligament;   

DOI  :  10.3390/pr10061148

来源: DOAJ

【 摘 要 】

In this study, the primary breakup of a high-speed diesel jet is investigated using a CFD methodology that combines an LES model with a VOF technique for free surface capture. Inner-nozzle turbulence and cavitation are simplified as the sinusoidal radial velocity with a given amplitude and frequency. The ligament and droplet formation process are captured, the liquid jet is disturbed by the radial velocity, and umbrella-shaped crests are created. Meanwhile, ligaments are formed from the edges of crests because of shear stress and surface tension. We investigate the effect on the characteristics of the surface wave and the liquid structure of different disturbance frequencies and amplitudes. The variation in the disturbance amplitude and frequency facilitates the formation of a variety of liquid structures, such as waves, upstream/downstream-directed bells, and droplet chains. Increasing the disturbance frequency reduces the growth rate of the surface waves of the liquid jet. With an increase in disturbance amplitude, the amplitude of surface waves evidently increases. Furthermore, as the disturbance frequency and amplitude increase, the thickness and Weber number of the radial liquid sheet decrease, and this causes the ligament diameter of the primary breakup to become small. Finally, the primary breakup time is investigated, and the time scale of the liquid jet primary breakup decreases as the disturbance amplitude increases, which indicates that an increase in the disturbance amplitude promotes the atomization of a disturbed liquid jet.

【 授权许可】

Unknown