Effect of shear-thinning on pressure-swirl atomization

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dc.contributor.authorJedelský, Jancs
dc.contributor.authorCejpek, Ondřejcs
dc.contributor.authorMalý, Milancs
dc.contributor.authorKadlec, Martincs
dc.contributor.authorSmilek, Jiřícs
dc.contributor.authorStrmiska, Pavelcs
dc.contributor.authorHájek, Ondřejcs
dc.coverage.issue2.2026cs
dc.coverage.volume255cs
dc.date.accessioned2025-10-17T05:53:11Z
dc.date.available2025-10-17T05:53:11Z
dc.date.issued2026-02-01cs
dc.description.abstractAtomization of non-Newtonian liquids is an underexplored topic despite their numerous spray applications. Key spray characteristics in such processes are mean droplet size and size distribution. Several studies demonstrate that non-Newtonian shear-thinning liquids can narrow the droplet size distribution compared to Newtonian liquids, reducing the number of excessively small or large droplets. Various spray applications benefit from minimized occurrence of droplets outside the desired size range. This applies to atomizers in spray towers or agricultural sprays where too-small droplets are blown away while those too large are ineffectively used. In this study, several non-Newtonian dilute aqueous solutions with different degrees of shear-thinning were prepared by mixing Xanthan Gum or Sodium carboxymethyl cellulose with deionized water. Their performance was compared with Newtonian sprays (water and water-glycerol solution) of comparable shear viscosity at defined shear rates. A common pressure-swirl atomizer was used, and a range of operational pressures along with varying viscosities allowed for examining the spraying process across a wide spectrum of Reynolds and Weber numbers. Velocity and size of droplets in the spray were measured simultaneously using a 1D phase Doppler anemometer. High-speed visualization was employed to track spray morphology and the breakup process. Calculations of the flow parameters inside the atomizer complemented these outcomes. Results show that varying viscosity and shear-thinning behaviour influence the flow dynamics from the liquid entry into the atomizer to the fully developed spray. Viscoelasticity complicates these processes further. The discharge occurs near the infinite-shear rate viscosity plateau, and its character depends, primarily on the flow conditions near the exit orifice. The shear-thinning and elasticity slightly affects liquid breakup, with production of more frequent and longer-lasting ligaments. Droplet size reduces with increasing pressure as expected, and this effect is more pronounced for non-Newtonians, the impact on the Relative span factor is inconsistent. Downstream droplet size increases for all liquids due to coalescive droplet collisions, with the secondary breakup and evaporation being ineffective.en
dc.description.abstractAtomization of non-Newtonian liquids is an underexplored topic despite their numerous spray applications. Key spray characteristics in such processes are mean droplet size and size distribution. Several studies demonstrate that non-Newtonian shear-thinning liquids can narrow the droplet size distribution compared to Newtonian liquids, reducing the number of excessively small or large droplets. Various spray applications benefit from minimized occurrence of droplets outside the desired size range. This applies to atomizers in spray towers or agricultural sprays where too-small droplets are blown away while those too large are ineffectively used. In this study, several non-Newtonian dilute aqueous solutions with different degrees of shear-thinning were prepared by mixing Xanthan Gum or Sodium carboxymethyl cellulose with deionized water. Their performance was compared with Newtonian sprays (water and water-glycerol solution) of comparable shear viscosity at defined shear rates. A common pressure-swirl atomizer was used, and a range of operational pressures along with varying viscosities allowed for examining the spraying process across a wide spectrum of Reynolds and Weber numbers. Velocity and size of droplets in the spray were measured simultaneously using a 1D phase Doppler anemometer. High-speed visualization was employed to track spray morphology and the breakup process. Calculations of the flow parameters inside the atomizer complemented these outcomes. Results show that varying viscosity and shear-thinning behaviour influence the flow dynamics from the liquid entry into the atomizer to the fully developed spray. Viscoelasticity complicates these processes further. The discharge occurs near the infinite-shear rate viscosity plateau, and its character depends, primarily on the flow conditions near the exit orifice. The shear-thinning and elasticity slightly affects liquid breakup, with production of more frequent and longer-lasting ligaments. Droplet size reduces with increasing pressure as expected, and this effect is more pronounced for non-Newtonians, the impact on the Relative span factor is inconsistent. Downstream droplet size increases for all liquids due to coalescive droplet collisions, with the secondary breakup and evaporation being ineffective.en
dc.formattextcs
dc.format.extent1-14cs
dc.format.mimetypeapplication/pdfcs
dc.identifier.citationINTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER. 2026, vol. 255, issue 2.2026, p. 1-14.en
dc.identifier.doi10.1016/j.ijheatmasstransfer.2025.127777cs
dc.identifier.issn0017-9310cs
dc.identifier.orcid0000-0002-1268-8434cs
dc.identifier.orcid0000-0002-7854-9533cs
dc.identifier.orcid0000-0002-1193-519Xcs
dc.identifier.orcid0009-0000-9115-2226cs
dc.identifier.orcid0000-0002-6553-1764cs
dc.identifier.orcid0009-0001-7124-9810cs
dc.identifier.orcid0000-0001-6647-6720cs
dc.identifier.other198891cs
dc.identifier.researcheridA-9224-2013cs
dc.identifier.researcheridAAY-7288-2021cs
dc.identifier.scopus23090535800cs
dc.identifier.scopus57189715785cs
dc.identifier.scopus55844628200cs
dc.identifier.urihttps://hdl.handle.net/11012/255584
dc.language.isoencs
dc.relation.ispartofINTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFERcs
dc.relation.urihttps://www.sciencedirect.com/science/article/pii/S0017931025011123cs
dc.rightsCreative Commons Attribution 4.0 Internationalcs
dc.rights.accessopenAccesscs
dc.rights.sherpahttp://www.sherpa.ac.uk/romeo/issn/0017-9310/cs
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/cs
dc.subjectShear-thinning liquidsen
dc.subjectNon-Newtonian liquidsen
dc.subjectRelative span factoren
dc.subjectShear viscosityen
dc.subjectExtensional viscosityen
dc.subjectPressure-swirl atomizeren
dc.subjectShear-thinning liquids
dc.subjectNon-Newtonian liquids
dc.subjectRelative span factor
dc.subjectShear viscosity
dc.subjectExtensional viscosity
dc.subjectPressure-swirl atomizer
dc.titleEffect of shear-thinning on pressure-swirl atomizationen
dc.title.alternativeEffect of shear-thinning on pressure-swirl atomizationen
dc.type.driverarticleen
dc.type.statusPeer-revieweden
dc.type.versionpublishedVersionen
sync.item.dbidVAV-198891en
sync.item.dbtypeVAVen
sync.item.insts2025.10.17 07:53:11en
sync.item.modts2025.10.16 12:32:44en
thesis.grantorVysoké učení technické v Brně. Fakulta chemická. Ústav fyzikální a spotřební chemiecs
thesis.grantorVysoké učení technické v Brně. Fakulta strojního inženýrství. Energetický ústavcs
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