Large eddy simulation of liquid-jet primary breakup in air crossflow

A robust two-phase-flow large-eddy-simulation methodology is applied to simulate the primary breakup of an axisymmetric liquid jet injected into an air crossflow at atmospheric pressure. The coupled level-set and volume-offluid method is implemented for accurate interface tracking. To deal with high...

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Main Authors:	Feng Xiao, Mehriar Dianat, Jim McGuirk
Format:	Default Article
Published:	2013
Subjects:	Aerospace engineering not elsewhere classified Mechanical engineering not elsewhere classified Other engineering not elsewhere classified untagged Aerospace Engineering Mechanical Engineering Engineering not elsewhere classified
Online Access:	https://hdl.handle.net/2134/13906
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id	rr-article-9229091
record_format	Figshare
spelling	rr-article-92290912013-01-01T00:00:00Z Large eddy simulation of liquid-jet primary breakup in air crossflow Feng Xiao (27219) Mehriar Dianat (1251702) Jim McGuirk (1252575) Aerospace engineering not elsewhere classified Mechanical engineering not elsewhere classified Other engineering not elsewhere classified untagged Aerospace Engineering Mechanical Engineering Engineering not elsewhere classified A robust two-phase-flow large-eddy-simulation methodology is applied to simulate the primary breakup of an axisymmetric liquid jet injected into an air crossflow at atmospheric pressure. The coupled level-set and volume-offluid method is implemented for accurate interface tracking. To deal with high liquid/gas density ratio, an extrapolated liquid-velocity field is created and used for momentum-equation discretization in the vicinity of the interface. Based on the local level-set value, sharp jumps in fluid density and viscosity are assumed across the interface. By simulating the nonturbulent inflow of a liquid jet into a nonturbulent gaseous crossflow, regular surface waves are observed in the large-eddy-simulation predictions on the upstreamside of the liquid jet, with the wavelength agreeing well with experimental measurements. The predicted wavelength decreases as the gaseous Weber number increases, implying that the surface waves arise from a Rayleigh–Taylor-type instability. The simulated velocity field shows that, as the instability grows, gaseous vortices develop in the wave troughs, further enhancing the breakup of the liquid core. The turbulent inflow of a liquid jet into a turbulent gas crossflow is also simulated, and the effect of turbulent eddies on the liquid-jet primary breakup is examined. The rescaling/recycling method for large-eddysimulation inlet-condition generation is implemented to generate realistic (i.e., physically correlated) turbulent inflows. It is found that it is the liquid rather than the gaseous turbulence that determines the initial liquid-jet instability and interface characteristics; further downstream, the turbulent liquid jet disintegrates more chaotically than the nonturbulent jet due to strong aerodynamic and turbulence effects. When appropriate turbulent inflows are specified, the liquid-jet penetration into the air crossflow (and the subsequent spread of the spray) is correctly predicted by the current large-eddy-simulation methodology, which displays good numerical robustness and accuracy for high liquid/gas density-ratio two-phase systems. 2013-01-01T00:00:00Z Text Journal contribution 2134/13906 https://figshare.com/articles/journal_contribution/Large_eddy_simulation_of_liquid-jet_primary_breakup_in_air_crossflow/9229091 CC BY-NC-ND 4.0
institution	Loughborough University
collection	Figshare
topic	Aerospace engineering not elsewhere classified Mechanical engineering not elsewhere classified Other engineering not elsewhere classified untagged Aerospace Engineering Mechanical Engineering Engineering not elsewhere classified
spellingShingle	Aerospace engineering not elsewhere classified Mechanical engineering not elsewhere classified Other engineering not elsewhere classified untagged Aerospace Engineering Mechanical Engineering Engineering not elsewhere classified Feng Xiao Mehriar Dianat Jim McGuirk Large eddy simulation of liquid-jet primary breakup in air crossflow
description	A robust two-phase-flow large-eddy-simulation methodology is applied to simulate the primary breakup of an axisymmetric liquid jet injected into an air crossflow at atmospheric pressure. The coupled level-set and volume-offluid method is implemented for accurate interface tracking. To deal with high liquid/gas density ratio, an extrapolated liquid-velocity field is created and used for momentum-equation discretization in the vicinity of the interface. Based on the local level-set value, sharp jumps in fluid density and viscosity are assumed across the interface. By simulating the nonturbulent inflow of a liquid jet into a nonturbulent gaseous crossflow, regular surface waves are observed in the large-eddy-simulation predictions on the upstreamside of the liquid jet, with the wavelength agreeing well with experimental measurements. The predicted wavelength decreases as the gaseous Weber number increases, implying that the surface waves arise from a Rayleigh–Taylor-type instability. The simulated velocity field shows that, as the instability grows, gaseous vortices develop in the wave troughs, further enhancing the breakup of the liquid core. The turbulent inflow of a liquid jet into a turbulent gas crossflow is also simulated, and the effect of turbulent eddies on the liquid-jet primary breakup is examined. The rescaling/recycling method for large-eddysimulation inlet-condition generation is implemented to generate realistic (i.e., physically correlated) turbulent inflows. It is found that it is the liquid rather than the gaseous turbulence that determines the initial liquid-jet instability and interface characteristics; further downstream, the turbulent liquid jet disintegrates more chaotically than the nonturbulent jet due to strong aerodynamic and turbulence effects. When appropriate turbulent inflows are specified, the liquid-jet penetration into the air crossflow (and the subsequent spread of the spray) is correctly predicted by the current large-eddy-simulation methodology, which displays good numerical robustness and accuracy for high liquid/gas density-ratio two-phase systems.
format	Default Article
author	Feng Xiao Mehriar Dianat Jim McGuirk
author_facet	Feng Xiao Mehriar Dianat Jim McGuirk
author_sort	Feng Xiao (27219)
title	Large eddy simulation of liquid-jet primary breakup in air crossflow
title_short	Large eddy simulation of liquid-jet primary breakup in air crossflow
title_full	Large eddy simulation of liquid-jet primary breakup in air crossflow
title_fullStr	Large eddy simulation of liquid-jet primary breakup in air crossflow
title_full_unstemmed	Large eddy simulation of liquid-jet primary breakup in air crossflow
title_sort	large eddy simulation of liquid-jet primary breakup in air crossflow
publishDate	2013
url	https://hdl.handle.net/2134/13906
_version_	1797738346985816064

Large eddy simulation of liquid-jet primary breakup in air crossflow

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