2007 Volume 13 Issue 1 Pages 7-16
The 3-D structure of liquid atomization behavior through a cylindrical nozzle is numerically investigated and visualized by a new type of integrated simulation technique. CFD (Computational Fluid Dynamics) analysis focused on the consecutive breakup of a liquid column, formation of liquid film, and generation of droplets of a cylindrical flow in the outlet section of the nozzle. Utilizing the governing equations for high-speed atomizing nozzle flow based on the LES-VOF model in conjunction with the CSF model, an integrated parallel computation is performed to clarify the detailed atomization process of a cylindrical nozzle flow and to acquire data, which is difficult to confirm by experiment, such as atomization length, liquid core shape, distribution droplet sizes, spray angle and droplet velocity profiles. According to the present analysis, the atomization rate and the droplets-gas two-phase flow characteristics are found to be controlled by the turbulence perturbation upstream of the injector nozzle, hydrodynamic instabilities at the gas-liquid interface, and shear stresses between the liquid core and periphery of the jet.
