Effect of shear-thinning on pressure-swirl atomization

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26210%2F26%3A0198891" target="_blank" >RIV/00216305:26210/26:0198891 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0017931025011123" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0017931025011123</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ijheatmasstransfer.2025.127777" target="_blank" >10.1016/j.ijheatmasstransfer.2025.127777</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of shear-thinning on pressure-swirl atomization

Popis výsledku v původním jazyce

Atomization 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.

Název v anglickém jazyce

Effect of shear-thinning on pressure-swirl atomization

Popis výsledku anglicky

Atomization 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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20301 - Mechanical engineering

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2026

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER

ISSN

0017-9310

e-ISSN

1879-2189

Svazek periodika

255

Číslo periodika v rámci svazku

2.2026

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

14

Strana od-do

1-14

Kód UT WoS článku

001576066900002

EID výsledku v databázi Scopus

2-s2.0-105016094869