Numerical Simulation of Internal Flow in a Large-scale Pressure-swirl Atomizer

This work is a continuation of experimental and computational studies of the internal flow field of a large-scale Danfoss atomizer presented at an earlier ILASS conference [1,2]. Fluent 6.1 is used to simulate the flow through the large-scale atomizer. The two-phase flow is modeled using three approaches: 1) a volume of fluid (VOF) method using a laminar flow assumption, 2) a VOF method using large eddy simulation (LES) turbulence modeling, and 3) a two-fluid Euler/Euler method using a laminar flow assumption. The primary focus of the analysis is on the internal flow characteristics in the swirl chamber. The air/water flow inside the atomizer is determined for two volume flow rates. Where possible, comparisons are made with measured velocity profiles and photographs of the air-core and the spray-cone from the atomizer. The CFD results compare favorably with experimental data of tangential and axial velocity distributions in the swirl chamber and static wall pressure. The size and shape of the air-core is also captured well by the numerical simulations.