Spray dispersion regimes following atomization in a turbulent co-axial gas jet

Huck, Peter; Osuna-Orozco, Rodrigo; Machicoane, Nathanaël; Aliseda, Alberto

doi:10.1017/jfm.2021.992

Cited by 8 publications

(10 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These profiles are also shown to match the jet self-similar solution (Pope 2000), where is the spreading rate derived by Huck et al. (2022) for a two-fluid coaxial jet. Overall, at axial distance downstream of the nozzle, the droplet axial velocity profiles can be considered fully developed.…”

Section: Experiments In the Spray Mid-fieldsupporting

confidence: 65%

“…(2019, 2020) and Huck et al. (2022). Briefly, the liquid and gas jets flow continuously during operation, with liquid jet diameter mm and annular gas jet diameter mm.…”

Section: Experimental Methodsmentioning

confidence: 97%

“…(2020) and Huck et al. (2022), where a liquid jet issues with co-flowing air into a chamber with quiescent air with varying ambient pressures but constant, room temperature conditions. As mentioned before, this is necessary in order to decouple the effects of pressure and temperature on the liquid and gas properties, and allows us to study the influence of gas pressure (and density) on the mechanics of atomization of the liquid phase.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Two-fluid coaxial atomization in a high-pressure environment

et al. 2022

Self Cite

View full text Add to dashboard Cite

We study the dynamics of atomization of a liquid column by a coaxial gas flow with varying gas pressures. Specifically, we analyse how the gas density increase associated with elevated gas pressures in the ambient and co-flowing gas jet influences the liquid destabilization and breakup process, as well as the resulting droplet formation and dispersion. We present new experimental results for a coaxial liquid–gas atomizer operating in a high-pressure environment, with gas–liquid momentum ratio in the range $M = 5\unicode{x2013}56$ and pressurized gas densities $\rho _g/\rho _0 = 1\unicode{x2013}5$ , where $\rho _0$ is the ambient gas density at standard conditions. High-speed shadowgraphy images are used to quantify the spatially and temporally varying liquid–gas interface in the spray near-field. Liquid core lengths, spreading angles and other spray metrics are presented, and the influence of gas density is identified from the comparison with atomization at atmospheric conditions. In the spray mid-field, phase Doppler interferometry is used in conjunction with laser Doppler velocimetry to quantify the droplet size and velocities, as well as their radial variations across the spray. Results show an increase in droplet size at elevated ambient pressures, when keeping the gas–liquid momentum ratio constant. Finally, we show that these observations are in line with predictions from the Kelvin–Helmholtz and Rayleigh–Taylor instabilities, both of which are relevant to the gas–liquid atomization process.

show abstract

Section: Experiments In the Spray Mid-fieldsupporting

confidence: 65%

“…(2019, 2020) and Huck et al. (2022). Briefly, the liquid and gas jets flow continuously during operation, with liquid jet diameter mm and annular gas jet diameter mm.…”

Section: Experimental Methodsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Two-fluid coaxial atomization in a high-pressure environment

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…(2021) and Huck et al. (2022). Different from the log-normal distribution and infinitely divisible distribution, the gamma distribution is based on the assumption that the fragments come from the rupture of objects in the form of threads or ligaments, i.e.…”

Section: Resultsmentioning

confidence: 97%

Droplet breakup in airflow with strong shear effect

Wang

Che

2022

J. Fluid Mech.

View full text Add to dashboard Cite

The deformation and breakup of droplets in airflows is important in spray and atomisation processes, but the shear effect in non-uniform airflow is rarely reported. In this study, the deformation and breakup of droplets in a shear flow of air is investigated experimentally using high-speed imaging, digital image processing and particle image velocimetry. The results show that in airflow with a strong shear effect, the droplet breakup exhibits unique features due to the uplift and stretching produced by the interaction between the deformed droplet and the shear layer. The breakup process can be divided into three stages according to the droplet morphology and the breakup mechanism, namely the sheet breakup, the swing breakup and the rim breakup stages. Theoretical analysis reveals that the swing breakup is governed by the transverse Rayleigh–Taylor instability. A regime map of the droplet breakup is produced, and the transitions between different regimes are obtained theoretically. The stretching liquid film during the droplet deformation and the fragment size distribution after droplet breakup are analysed quantitatively, and the results show that they are determined by the competition of breakup at different stages affected by the shear. Finally, the effect of the droplet viscosity is investigated, and the viscosity inhibits the droplet breakup in a strong shear airflow.

show abstract

“…2017), gamma (Huck et al. 2022) or multimodal (Balachandar et al. 2020; Jiang & Ling 2021) distribution, when more than one formation process is involved.…”

Section: Identification Of Atomization Patterns and Processesmentioning

confidence: 99%

Analysis of liquid column atomization by annular dual-nozzle gas jet flow

2022

View full text Add to dashboard Cite

The atomization of a water column by a gas jet flow (Reynolds number $\sim O(10^{4}\unicode{x2013}10^{5})$ ) issued from a two-stage annular nozzle is investigated experimentally. Varying the nozzle geometry, the momentum flux ratio of the upper and lower jets, and the water flow rate, we measure the processes of atomization with high-speed imaging, analysed analytically into four regimes. In the bulk atomization regime, the atomization is driven by the lower jet, but it is forced to occur earlier by the stronger upper jet before the water column reaches the lower jet in the droplet atomization regime. Interestingly, the size of the atomized droplets remains unaffected by the momentum flux ratio of upper to lower jets. The atomization process is governed by the Rayleigh–Taylor instability, by which the estimated droplet size agrees well with the measurement. In the backflow regime, a strong reverse flow is induced to force a substantial portion of atomized droplets to be drawn backward to the nozzle; a floating liquid column regime is captured transitionally, i.e. the column stagnates near the lower nozzle when the water flow rate is very low. To understand the mechanisms of each regime, the single-phase jet flow is measured separately using particle image velocimetry, and implemented into the control volume analysis with which we predicted analytically and validated the conditions for the occurrence of each regime. It is found that the acceleration of gas flow (velocity gradient) experienced by the falling water is the key parameter to drive the atomization.

show abstract

Spray dispersion regimes following atomization in a turbulent co-axial gas jet

Cited by 8 publications

References 51 publications

Two-fluid coaxial atomization in a high-pressure environment

Two-fluid coaxial atomization in a high-pressure environment

Droplet breakup in airflow with strong shear effect

Analysis of liquid column atomization by annular dual-nozzle gas jet flow

Contact Info

Product

Resources

About