Large-eddy simulation in a Sonolator high-pressure homogeniser

This paper examines the fluid dynamics of a pilot-scale high-pressure homogeniser using large-eddy simulation. The mixer consists of a non-planar elliptic jet released into a confined cylindrical chamber. The simulated results are validated by comparing mean quantities with published experimental data. The evolution of the shear layers in the jet near-field shows a localised region of high turbulent energy dissipation rate in the major plane, whereas in the minor plane the dissipation rate is of smaller magnitude and spreads over a wider region. The validity of the turbulence isotropy assumption, typically made in dispersed-phase modelling, is examined. Energy spectra exhibit an amplification close to the nozzle at frequencies associated with vortex shedding. Kolmogorovs classical 2/3 scaling in the second-order structure functions is found to be overshadowed by vortex shedding, resulting in steeper slopes in the jet near-field, where the rate of energy dissipation assumes the largest value in the mixer. (C) 2019 Elsevier Ltd. All rights reserved.