REVIEW 3 major objections 2 minor 2 cited by
Confinement-Induced Suppression of Jet Drop Size by Bubble Bursting in Shallow Liquids
T0 review · 3 major / 2 minor · reviewed 2026-06-30 · grok-4.3
Pith's one-line read A nearby solid wall in shallow liquids makes bursting bubbles produce smaller jet drops through viscous sticking.
desk verdict Numerical observation of smaller jet drops from wall viscous sticking in shallow bubble bursting, but no convergence or validation details provided to address artifact concerns. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
Wall-induced viscous sticking effect that suppresses upward motion of the cavity bottom and produces steeper cavity geometry during wave focusing.
What would settle it
Direct high-speed imaging that measures cavity-bottom velocity or final jet drop size in controlled experiments with varying liquid depths but matched initial bubble shapes would show smaller drops in shallow cases if the mechanism holds.
Extended reading notes
Core claim
Bubble bursting in shallow liquids produces smaller jet drops because a wall-induced viscous sticking effect suppresses the upward motion of the cavity bottom, resulting in a steeper cavity geometry during capillary-wave focusing. The effect persists even for fixed initial bubble shapes. A semi-empirical scaling law predicts the resulting jet drop radius from the Ohnesorge number and the initial bubble-wall distance.
Load-bearing premise
The numerical method and boundary conditions accurately capture the viscous interaction between the fluid and the nearby wall.
Editorial extensions
If this is right
- Jet drops become smaller and more numerous under geometric confinement.
- The scaling law gives drop radius directly from viscosity measure and wall distance.
- Geometric confinement becomes a controllable factor for aerosol output.
- Prediction and control of drop sizes become possible in shallow-layer systems.
Reading between the lines
- Aerosol models for oceans or thin coatings may need to include bottom-boundary distance as a variable.
- Varying liquid depth while holding bubble shape fixed would provide a clean experimental test of the scaling.
- The sticking mechanism could appear in other confined jetting flows such as inkjet printing or microfluidic breakup.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript presents numerical simulations of bubble bursting in shallow liquid layers. It claims that a nearby solid boundary produces smaller and more numerous jet drops than in deep pools, even with identical initial bubble shapes. The proposed mechanism is a wall-induced viscous sticking effect that suppresses upward motion of the cavity bottom, yielding a steeper cavity geometry at the moment of capillary-wave focusing. A semi-empirical scaling law is introduced that expresses the resulting jet-drop radius in terms of the Ohnesorge number and the initial bubble-wall distance.
Significance. If the numerical results are free of discretization artifacts, the work identifies geometric confinement as a controlling parameter in jet-drop formation and supplies a predictive scaling relation for aerosol generation in shallow-liquid settings. Such a relation would be useful for modeling sea-spray, industrial bubbling, and related multiphase processes. The identification of the viscous-sticking mechanism, if confirmed, adds a concrete physical picture to an otherwise geometry-driven phenomenon.
major comments (3)
- [Numerical Methods] Numerical Methods (presumably §2 or equivalent): the manuscript provides no grid-convergence study or boundary-layer resolution test demonstrating that the reported viscous sticking and cavity-bottom suppression survive systematic refinement. Because the effect is localized in a thin viscous layer whose thickness scales with local time, under-resolution or scheme-induced damping near the no-slip wall could produce the observed drop-size reduction as an artifact.
- [Scaling law] Scaling-law derivation (presumably §4 or Results): the semi-empirical relation for drop radius is stated to depend on Oh and bubble-wall distance, yet no information is given on whether the functional form and fitted coefficients were obtained from the same data set used to demonstrate the effect, nor whether an independent validation set or cross-validation was performed. This raises a circularity concern for the predictive claim.
- [Results] Validation against experiment: the central claim that shallow-layer bursting yields measurably smaller drops rests entirely on the simulations; no quantitative comparison with existing or new experimental data for confined geometries is reported, leaving open whether the viscous-sticking mechanism is reproduced under laboratory conditions.
minor comments (2)
- [Abstract] Abstract and introduction should explicitly state the range of Oh and dimensionless wall distances explored so that the domain of the scaling law is clear.
- [Figures] Figure captions for cavity-shape and velocity-field plots should indicate the grid spacing used in the wall region and whether the fields are instantaneous or time-averaged.
Simulated Author's Rebuttal
We thank the referee for the careful reading and constructive comments. We address each major point below, indicating revisions to the manuscript where appropriate.
read point-by-point responses
-
Referee: [Numerical Methods] Numerical Methods (presumably §2 or equivalent): the manuscript provides no grid-convergence study or boundary-layer resolution test demonstrating that the reported viscous sticking and cavity-bottom suppression survive systematic refinement. Because the effect is localized in a thin viscous layer whose thickness scales with local time, under-resolution or scheme-induced damping near the no-slip wall could produce the observed drop-size reduction as an artifact.
Authors: We agree that demonstrating numerical convergence is essential, particularly for the thin viscous layer near the wall. In the revised manuscript we will add a grid-convergence study (including successive refinements and boundary-layer resolution checks) showing that the cavity-bottom suppression, jet-drop statistics, and viscous-sticking mechanism remain unchanged under refinement. revision: yes
-
Referee: [Scaling law] Scaling-law derivation (presumably §4 or Results): the semi-empirical relation for drop radius is stated to depend on Oh and bubble-wall distance, yet no information is given on whether the functional form and fitted coefficients were obtained from the same data set used to demonstrate the effect, nor whether an independent validation set or cross-validation was performed. This raises a circularity concern for the predictive claim.
Authors: The functional form was motivated by viscous-boundary-layer scaling arguments prior to fitting. In the revision we will explicitly document the derivation steps, the data used for coefficient determination, and any separation into fitting versus validation subsets, together with quantitative measures of predictive accuracy on held-out cases. revision: yes
-
Referee: [Results] Validation against experiment: the central claim that shallow-layer bursting yields measurably smaller drops rests entirely on the simulations; no quantitative comparison with existing or new experimental data for confined geometries is reported, leaving open whether the viscous-sticking mechanism is reproduced under laboratory conditions.
Authors: The present work is a numerical investigation whose primary goal is to identify the confinement mechanism and the associated scaling. Direct quantitative experimental validation for shallow-layer geometries is not included and would require new laboratory measurements that lie outside the scope of this study. In the revision we will add a dedicated discussion comparing the scaling predictions against existing deep-pool experiments and outlining testable signatures for future shallow-layer experiments. revision: partial
Circularity Check
No significant circularity detected
full rationale
The paper's central claims rest on numerical identification of a wall-induced viscous sticking effect and the subsequent development of a semi-empirical scaling law expressed in terms of Ohnesorge number and bubble-wall distance. No equations, fitting procedures, or self-citations are exhibited in the provided text that reduce the reported predictions or scaling law to tautological re-statements of the input simulation data or prior author results. The derivation chain therefore remains self-contained against external benchmarks, with the scaling law presented as an independent organizing relation rather than a direct re-labeling of fitted outputs.
Assumptions & free parameters
Cite this review
Pith. "Pith review of Confinement-Induced Suppression of Jet Drop Size by Bubble Bursting in Shallow Liquids." pith.science (2026). https://pith.science/paper/JVDBMPB6
@misc{pith2026260628609,
author = {Pith},
title = {Pith review of: Confinement-Induced Suppression of Jet Drop Size by Bubble Bursting in Shallow Liquids},
year = {2026},
howpublished = {\url{https://pith.science/paper/JVDBMPB6}},
note = {Machine review of arXiv:2606.28609}
}
read the original abstract
Bubble bursting is a major source of aerosol generation in a wide range of natural and industrial systems. While the resulting jet dynamics have been extensively studied in deep liquid pools, bubble bursting often occurs in shallow liquid layers where the influence of the nearby solid boundary remains poorly understood. Here, we show numerically that a shallow liquid layer produces smaller and more numerous jet drops, even when the initial bubble shape is unchanged. We identify a wall-induced viscous sticking effect that suppresses the upward motion of the cavity bottom, leading to a steeper cavity geometry during capillary-wave focusing. We further develop a semi-empirical scaling law that predicts the jet drop radius as a function of the Ohnesorge number and the initial bubble-wall distance. Our results establish geometric confinement as a governing factor in bubble bursting and provide a framework for predicting and controlling aerosol generation in shallow liquid environments.
Figures
Forward citations
Cited by 2 Pith papers
-
Self-similar Worthington jets
Bursting bubbles form self-similar Worthington jets with radius ~τ^0.63, so inertia dominates capillarity and water yields O(1) nm aerosols.
-
Bubble bursting in a sessile droplet
A sessile droplet's curved free surface and confinement lower the Laplace-number threshold for Worthington-jet droplet emission and produce smaller, faster jets than an infinite liquid bath.
Reference graph
Works this paper leans on
-
[1]
J. C. Bird, R. De Ruiter, L. Courbin, and H. A. Stone, Daughter bubble cascades produced by folding of rup- tured thin films, Nature465, 759 (2010)
2010
-
[2]
J. Feng, M. Roch´ e, D. Vigolo, L. N. Arnaudov, S. D. Stoyanov, T. D. Gurkov, G. G. Tsutsumanova, and H. A. Stone, Nanoemulsions obtained via bubble-bursting at a compound interface, Nat. Phys.10, 606 (2014)
2014
-
[3]
Veron, Ocean spray, Annu
F. Veron, Ocean spray, Annu. Rev. Fluid Mech.47, 507 (2015)
2015
-
[4]
Deike, Mass transfer at the ocean–atmosphere inter- face: The role of wave breaking, droplets, and bubbles, Annu
L. Deike, Mass transfer at the ocean–atmosphere inter- face: The role of wave breaking, droplets, and bubbles, Annu. Rev. Fluid Mech.54, 191 (2022)
2022
-
[5]
Bourouiba, Fluid dynamics of respiratory infectious diseases, Annu
L. Bourouiba, Fluid dynamics of respiratory infectious diseases, Annu. Rev. Biomed. Eng.23, 547 (2021)
2021
-
[6]
Bourouiba, The fluid dynamics of disease transmission, Annu
L. Bourouiba, The fluid dynamics of disease transmission, Annu. Rev. Fluid Mech.53, 473 (2020)
2020
-
[7]
X. Wang, G. B. Deane, K. A. Moore, O. S. Ryder, M. D. Stokes, C. M. Beall, D. B. Collins, M. V. Santander, S. M. Burrows, C. M. Sultana,et al., The role of jet and film drops in controlling the mixing state of submicron sea spray aerosol particles, Proc. Natl. Acad. Sci.114, 6978 (2017)
2017
-
[8]
Y. S. Joung and C. R. Buie, Aerosol generation by rain- drop impact on soil, Nat. Comm.6, 6083 (2015)
2015
Show all 30 references
-
[9]
Y. S. Joung, Z. Ge, and C. R. Buie, Bioaerosol generation by raindrops on soil, Nat. Commun.8, 1 (2017)
2017
-
[10]
Bashkatov, F
A. Bashkatov, F. B¨ urkle, C ¸ . Demirkır, W. Ding, V. San- jay, A. Babich, X. Yang, G. Mutschke, J. Czarske, D. Lohse,et al., Electrolyte droplet spraying in h2 bub- bles during water electrolysis under normal and micro- gravity conditions, Nat. Comm.16, 4580 (2025)
2025
-
[11]
N. V. Upot, A. Mahvi, K. Fazle Rabbi, J. Li, A. M. Jacobi, and N. Miljkovic, Scalable and resilient etched metallic micro-and nanostructured surfaces for enhanced flow boiling, ACS Appl. Nano Mater.4, 6648 (2021)
2021
-
[12]
Cuadros, Y
J. Cuadros, Y. Rivera, C. Berna, A. Escriv´ a, J. Mu˜ noz- Cobo, G. Monr´ os-Andreu, and S. Chiva, Characteriza- tion of the gas-liquid interfacial waves in vertical up- ward co-current annular flows, Nucl. Eng. Des.346, 112 (2019)
2019
-
[13]
Y. Zhou, B. Ji, C. Zhao, H. Bo, Y. Zhang, and H. Li, Role of bubble dynamics in heat and mass transfer in annular flows, Int. J. Therm. Sci.191, 108348 (2023)
2023
-
[14]
Deike, E
L. Deike, E. Ghabache, G. Liger-Belair, A. K. Das, S. Za- leski, S. Popinet, and T. S´ eon, Dynamics of jets produced by bursting bubbles, Phys. Rev. Fluids3, 013603 (2018)
2018
-
[15]
C. F. Brasz, C. T. Bartlett, P. L. Walls, E. G. Flynn, Y. E. Yu, and J. C. Bird, Minimum size for the top jet drop from a bursting bubble, Phys. Rev. Fluids3, 074001 (2018)
2018
-
[16]
A. M. Ga˜ n´ an-Calvo and J. M. L´ opez-Herrera, On the physics of transient ejection from bubble bursting, J. Fluid Mech.929, A12 (2021)
2021
-
[17]
J. M. Gordillo and F. J. Blanco-Rodr´ ıguez, Theory of the jets ejected after the inertial collapse of cavities with applications to bubble bursting jets, Phys. Rev. Fluids8, 073606 (2023)
2023
-
[18]
Singh and A
D. Singh and A. K. Das, Numerical investigation of the collapse of a static bubble at the free surface in the pres- ence of neighbors, Phys. Rev. Fluids4, 023602 (2019)
2019
-
[19]
C. G. Lee, S. Y. Lee, C.-T. Ha, and J. H. Lee, Bursting jet in two tandem bubbles at the free surface, Phys. Fluids 34(2022)
2022
-
[20]
Aur´ egan, N
T. Aur´ egan, N. Daniel, M. Mazzatenta, and L. Deike, Jet drop production from bubbles with neighbors, Phys. Rev. Fluids11, 043601 (2026)
2026
-
[21]
Basilisk,http://basilisk.fr/
-
[22]
Sanjay, D
V. Sanjay, D. Lohse, and M. Jalaal, Bursting bubble in a viscoplastic medium, J. Fluid Mech.922, A2 (2021)
2021
-
[23]
Krishnan, B
S. Krishnan, B. A. Puthenveettil, and E. J. Hopfinger, Dynamics of collapse of free-surface bubbles: effects of gravity and viscosity, J. Fluid Mech.980, A36 (2024)
2024
-
[24]
Z. Mou, Z. Zheng, Z. Jian, C. Antonini, C. Josserand, and M.-J. Thoraval, Singular jets and entrapments from compound drop impact, Phys. Rev. Fluids11, 013602 (2026)
2026
-
[25]
Krishnan, E
S. Krishnan, E. J. Hopfinger, and B. A. Puthenveettil, On the scaling of jetting from bubble collapse at a liquid surface, J. Fluid Mech.822, 791 (2017)
2017
-
[26]
Gordillo and J
J. Gordillo and J. Rodr´ ıguez-Rodr´ ıguez, Capillary waves control the ejection of bubble bursting jets, J. Fluid Mech.867, 556 (2019)
2019
-
[27]
F. J. Blanco-Rodr´ ıguez and J. Gordillo, On the jets pro- duced by drops impacting a deep liquid pool and by bursting bubbles, J. Fluid Mech.916, A37 (2021)
2021
-
[28]
J. R. Blake, A note on the image system for a stokeslet in a no-slip boundary, Math. Proc. Camb. Philos. Soc. 70, 303 (1971)
1971
-
[29]
Happel and H
J. Happel and H. Brenner,Low Reynolds Number Hy- drodynamics(Martinus Nijhoff Publishers, The Hague, 1983)
1983
-
[30]
Ma¨ es, A
P.-A. Ma¨ es, A. Amirfazli, and C. Josserand, Birth of a bubble: drop impact onto a thin liquid film for an im- miscible three-fluid system, J. Fluid Mech
Reviewed June 30, 2026 · model on record in the stance chip above.
Discussion (0). Continue with ORCID to comment.