2023
Hui Wang
Splash of high-speed drop impact: numerical insights and applications to oil-contaminated pools PhD Thesis
Paris, HESAM, 2023.
@phdthesis{wang2023splash,
title = {Splash of high-speed drop impact: numerical insights and applications to oil-contaminated pools},
author = {Hui Wang},
url = {https://huiwanglab.com/wp-content/uploads/2024/03/ENSAM_WANG-Hui_2023_archivage.pdf},
doi = {https://theses.fr/2023HESAE082},
year = {2023},
date = {2023-12-12},
urldate = {2023-12-12},
school = {Paris, HESAM},
abstract = {The impact of a liquid drop onto a deep liquid pool induces a broad range of physical phenomena, constituting a fascinating and crucial area of study with far-reaching implications across industrial and natural domains. Despite significant advancements in our comprehension, many key aspects of the process remain scarcely explored, particularly concerning the intricate interplay within the most energetic impact conditions. At high-speed impact velocity, a thin-walled liquid crown arises, swiftly followed by necking in and air encapsulation, giving rise to a distinctive ‘Bubble Canopy’ structure. Such cases, characterized by shorter time scales and increased complexities of splash, pose formidable challenges for both experimental and numerical approaches and have thus received limited prior attention.
In this thesis, we employ the latest state-of-the-art numerical methods to delve into the intri- cate dynamics that unfold during drop impact, with a primary focus on high-speed impact regimes. Through axisymmetric configurations, we systematically characterize a wide array of repeatable early jet behaviours and crater evolution modes, facilitating a comprehensive exploration of how liquid properties progressively shape the impact phenomenon. A thorough analysis of splashing details within the bubble canopy regime is subsequently conducted through a high-resolution 3D simulation. We further extend our inquiry to the scenario featuring the presence of a floating oil slick on the pool surface, introducing an additional layer of complexity and practical relevance to the post-oil spill conditions. Intriguing interactions with varied oil layer thicknesses and dispersants are examined. Through this research, we aim to provide new insights into the dynamics of high-speed drop impact splash, shedding light on previously unexplored aspects of this intriguing phenomenon.},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
The impact of a liquid drop onto a deep liquid pool induces a broad range of physical phenomena, constituting a fascinating and crucial area of study with far-reaching implications across industrial and natural domains. Despite significant advancements in our comprehension, many key aspects of the process remain scarcely explored, particularly concerning the intricate interplay within the most energetic impact conditions. At high-speed impact velocity, a thin-walled liquid crown arises, swiftly followed by necking in and air encapsulation, giving rise to a distinctive ‘Bubble Canopy’ structure. Such cases, characterized by shorter time scales and increased complexities of splash, pose formidable challenges for both experimental and numerical approaches and have thus received limited prior attention.
In this thesis, we employ the latest state-of-the-art numerical methods to delve into the intri- cate dynamics that unfold during drop impact, with a primary focus on high-speed impact regimes. Through axisymmetric configurations, we systematically characterize a wide array of repeatable early jet behaviours and crater evolution modes, facilitating a comprehensive exploration of how liquid properties progressively shape the impact phenomenon. A thorough analysis of splashing details within the bubble canopy regime is subsequently conducted through a high-resolution 3D simulation. We further extend our inquiry to the scenario featuring the presence of a floating oil slick on the pool surface, introducing an additional layer of complexity and practical relevance to the post-oil spill conditions. Intriguing interactions with varied oil layer thicknesses and dispersants are examined. Through this research, we aim to provide new insights into the dynamics of high-speed drop impact splash, shedding light on previously unexplored aspects of this intriguing phenomenon.
In this thesis, we employ the latest state-of-the-art numerical methods to delve into the intri- cate dynamics that unfold during drop impact, with a primary focus on high-speed impact regimes. Through axisymmetric configurations, we systematically characterize a wide array of repeatable early jet behaviours and crater evolution modes, facilitating a comprehensive exploration of how liquid properties progressively shape the impact phenomenon. A thorough analysis of splashing details within the bubble canopy regime is subsequently conducted through a high-resolution 3D simulation. We further extend our inquiry to the scenario featuring the presence of a floating oil slick on the pool surface, introducing an additional layer of complexity and practical relevance to the post-oil spill conditions. Intriguing interactions with varied oil layer thicknesses and dispersants are examined. Through this research, we aim to provide new insights into the dynamics of high-speed drop impact splash, shedding light on previously unexplored aspects of this intriguing phenomenon.
Shuo Liu, Hui Wang, Annie-Claude Bayeul-Lainé, Cheng Li, Joseph Katz, Olivier Coutier-Delgosha
Wave statistics and energy dissipation of shallow-water breaking waves in a tank with a level bottom Journal Article
In: Journal of Fluid Mechanics, vol. 975, pp. A25, 2023.
@article{liu2023wave,
title = {Wave statistics and energy dissipation of shallow-water breaking waves in a tank with a level bottom},
author = {Shuo Liu and Hui Wang and Annie-Claude Bayeul-Lainé and Cheng Li and Joseph Katz and Olivier Coutier-Delgosha},
url = {https://huiwanglab.com/wp-content/uploads/2024/03/wave_statistics_and_energy_dissipation_of_shallowwater_breaking_waves_in_a_tank_with_a_level_bottom.pdf},
doi = { https://doi.org/10.1017/jfm.2023.876},
year = {2023},
date = {2023-11-16},
urldate = {2023-11-16},
journal = {Journal of Fluid Mechanics},
volume = {975},
pages = {A25},
publisher = {Cambridge University Press},
abstract = {The present study focuses on two-dimensional direct numerical simulations of shallow-water breaking waves, specifically those generated by a wave plate at constant water depths. The primary objective is to quantitatively analyse the dynamics, kinematics and energy dissipation associated with wave breaking. The numerical results exhibit good agreement with experimental data in terms of free-surface profiles during wave breaking. A parametric study was conducted to examine the influence of various wave properties and initial conditions on breaking characteristics. According to research on the Bond number (Bo, the ratio of gravitational to surface tension forces), an increased surface tension leads to the formation of more prominent parasitic capillaries at the forwards face of the wave profile and a thicker plunging jet, which causes a delayed breaking time and is tightly correlated with the main cavity size. A close relationship between wave statistics and the initial conditions of the wave plate is discovered, allowing for the classification of breaker types based on the ratio of wave height to water depth, H/d. Moreover, an analysis based on inertial scaling arguments reveals that the energy dissipation rate due to breaking can be linked to the local geometry of the breaking crest Hb/d, and exhibits a threshold behaviour, where the energy dissipation approaches zero at a critical value of Hb/d. An empirical scaling of the breaking parameter is proposed as b = a(Hb/d − χ0)n, where χ0 = 0.65 represents the breaking threshold and n = 1.5 is a power law determined through the best fit to the numerical results.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The present study focuses on two-dimensional direct numerical simulations of shallow-water breaking waves, specifically those generated by a wave plate at constant water depths. The primary objective is to quantitatively analyse the dynamics, kinematics and energy dissipation associated with wave breaking. The numerical results exhibit good agreement with experimental data in terms of free-surface profiles during wave breaking. A parametric study was conducted to examine the influence of various wave properties and initial conditions on breaking characteristics. According to research on the Bond number (Bo, the ratio of gravitational to surface tension forces), an increased surface tension leads to the formation of more prominent parasitic capillaries at the forwards face of the wave profile and a thicker plunging jet, which causes a delayed breaking time and is tightly correlated with the main cavity size. A close relationship between wave statistics and the initial conditions of the wave plate is discovered, allowing for the classification of breaker types based on the ratio of wave height to water depth, H/d. Moreover, an analysis based on inertial scaling arguments reveals that the energy dissipation rate due to breaking can be linked to the local geometry of the breaking crest Hb/d, and exhibits a threshold behaviour, where the energy dissipation approaches zero at a critical value of Hb/d. An empirical scaling of the breaking parameter is proposed as b = a(Hb/d − χ0)n, where χ0 = 0.65 represents the breaking threshold and n = 1.5 is a power law determined through the best fit to the numerical results.
Hui Wang, Shuo Liu, Annie-Claude Bayeul-Lainé, David Murphy, Joseph Katz, Olivier Coutier-Delgosha
Analysis of high-speed drop impact onto deep liquid pool Journal Article
In: Journal of Fluid Mechanics, vol. 972, pp. A31, 2023.
@article{wang2023analysis,
title = {Analysis of high-speed drop impact onto deep liquid pool},
author = {Hui Wang and Shuo Liu and Annie-Claude Bayeul-Lainé and David Murphy and Joseph Katz and Olivier Coutier-Delgosha},
url = {https://huiwanglab.com/wp-content/uploads/2024/03/Analysis_of_high-speed_drop_impact_onto_deep_liquid_pool-1.pdf},
doi = {https://doi.org/10.1017/jfm.2023.701},
year = {2023},
date = {2023-10-04},
urldate = {2023-10-04},
journal = {Journal of Fluid Mechanics},
volume = {972},
pages = {A31},
publisher = {Cambridge University Press},
abstract = {The present work is devoted to the analysis of drop impact on a deep liquid pool, focusing on the high-energy splashing regimes caused by large raindrops at high velocities. Such cases are characterized by short time scales and complex mechanisms, thus they have received very little attention until now. The BASILISK open-source solver is used to perform three-dimensional direct numerical simulations. The capabilities of octree adaptive mesh refinement techniques enable capturing of the small-scale features of the flow, while the volume of fluid approach combined with a balanced-force surface-tension calculation is applied to advect the volume fraction of the liquids and reconstruct the interfaces. The numerical results compare well with experimental visualizations: both the evolution of crown and cavity, the emanation of ligaments, the formation of bubble canopy and the growth of a downward-moving spiral jet that pierces through the cavity bottom, are correctly reproduced. Reliable quantitative agreements are also obtained regarding the time evolution of rim positions, cavity dimensions and droplet distributions through an observation window. Furthermore, simulation gives access to various aspects of the internal flows, which allows us to better explain the observed physical phenomena. Details of the early-time dynamics of bubble ring entrapment and splashing performance, the formation/collapse of bubble canopy and the spreading of drop liquid are discussed. The statistics of droplet size show the bimodal distribution in time, corroborating distinct primary mechanisms of droplet production at different stages.},
key = {drops, breakup/coalescence},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The present work is devoted to the analysis of drop impact on a deep liquid pool, focusing on the high-energy splashing regimes caused by large raindrops at high velocities. Such cases are characterized by short time scales and complex mechanisms, thus they have received very little attention until now. The BASILISK open-source solver is used to perform three-dimensional direct numerical simulations. The capabilities of octree adaptive mesh refinement techniques enable capturing of the small-scale features of the flow, while the volume of fluid approach combined with a balanced-force surface-tension calculation is applied to advect the volume fraction of the liquids and reconstruct the interfaces. The numerical results compare well with experimental visualizations: both the evolution of crown and cavity, the emanation of ligaments, the formation of bubble canopy and the growth of a downward-moving spiral jet that pierces through the cavity bottom, are correctly reproduced. Reliable quantitative agreements are also obtained regarding the time evolution of rim positions, cavity dimensions and droplet distributions through an observation window. Furthermore, simulation gives access to various aspects of the internal flows, which allows us to better explain the observed physical phenomena. Details of the early-time dynamics of bubble ring entrapment and splashing performance, the formation/collapse of bubble canopy and the spreading of drop liquid are discussed. The statistics of droplet size show the bimodal distribution in time, corroborating distinct primary mechanisms of droplet production at different stages.