TY - JOUR
T1 - Analysis of viscous fluid flow in a pressure-swirl atomizer using large-eddy simulation
AU - Laurila, E.
AU - Roenby, J.
AU - Maakala, V.
AU - Peltonen, P.
AU - Kahila, H.
AU - Vuorinen, V.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - 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.
AB - 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.
KW - Hollow cone spray
KW - isoAdvector
KW - Large-eddy simulation
KW - LES
KW - Pressure-swirl atomizer
KW - Primary atomization
KW - Two-phase flow
KW - VOF
KW - Volume-of-fluid method
UR - http://www.scopus.com/inward/record.url?scp=85057049563&partnerID=8YFLogxK
U2 - 10.1016/j.ijmultiphaseflow.2018.10.008
DO - 10.1016/j.ijmultiphaseflow.2018.10.008
M3 - Journal article
AN - SCOPUS:85057049563
SN - 0301-9322
VL - 113
SP - 371
EP - 388
JO - International Journal of Multiphase Flow
JF - International Journal of Multiphase Flow
ER -