Analysis of viscous fluid flow in a pressure-swirl atomizer using large-eddy simulation
•Numerical investigation of a large-scale, asymmetric pressure-swirl atomizer.•The simulations include inner nozzle flow and the onset of liquid film instability.•Various nozzle operation modes revealed by a Reynolds number sweep.•Liquid sheet types characterized for different Reynolds numbers.•Rich...
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Published in: | International journal of multiphase flow 2019-04, Vol.113, p.371-388 |
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Main Authors: | , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | •Numerical investigation of a large-scale, asymmetric pressure-swirl atomizer.•The simulations include inner nozzle flow and the onset of liquid film instability.•Various nozzle operation modes revealed by a Reynolds number sweep.•Liquid sheet types characterized for different Reynolds numbers.•Rich physics include vortex core, Dean vortices, sheet flapping and breakup.
A computational fluid dynamics study is carried out on the inner nozzle flow and onset of liquid sheet instability in a large-scale pressure-swirl atomizer with asymmetric inflow configuration for high viscosity fluids. Large-eddy simulations (LES) of the two-phase flow indicate the unsteady flow character inside the nozzle and its influence on liquid sheet formation. A novel geometric volume-of-fluid (VOF) method by Roenby et al. (2016), termed isoAdvector, is applied for sharp interface capturing. We carry out a Reynolds number sweep (420 ≤ Re ≤ 5300) in order to investigate the link between the asymmetric inner nozzle flow and liquid sheet characteristics in laminar, transitional and fully turbulent conditions. Inside the nozzle, the numerical simulations reveal counter-rotating Dean vortices, flow impingement locations, and strong asymmetric flow features at all investigated Reynolds numbers. A helical, rotating gaseous core is observed when Re ≥ 1660. For laminar flow (Re=420), an S-shaped liquid film is observed, while the gas core presence at Re ≥ 1660 results in a hollow cone liquid sheet. For the intermediate value Re=830, the numerical simulations indicate a liquid sheet of mixed type. Consequences of the inflow asymmetry and Reynolds number to the uniformity of the injected liquid mass distribution and liquid sheet instability are pointed out. |
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ISSN: | 0301-9322 1879-3533 |
DOI: | 10.1016/j.ijmultiphaseflow.2018.10.008 |