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Key research themes
1. How do fluid properties and dynamic conditions control drop breakup morphologies and fragment size distributions?
This research theme investigates the fundamental fluid mechanical processes governing drop breakup under various dynamic flow conditions, such as aerodynamic, turbulent, shock-induced, or collisional regimes. It emphasizes the characterization of breakup modes, the resulting fragment or daughter drop size distributions, and the transition criteria between regimes based on dimensionless parameters (e.g., Weber, Ohnesorge numbers). Understanding these mechanisms is critical for predicting atomization and droplet fragmentation in engineering and natural systems.
Key finding: This study links pinch-off and daughter (satellite) drop formation mechanisms to interplay of capillary waves and local neck curvature during coalescence of unequal sized drops, revealing that sharper axial curvature... Read more
Key finding: Through combined shadowgraphy and digital holography, the paper experimentally demonstrates that dual-bag breakup of droplets produces bi-modal size distributions of child droplets, contrasting with tri-modal distributions in... Read more
Key finding: The research classifies shock–droplet interaction into early-stage wave dynamics and later stage breakup dynamics, identifying two primary breakup modes: shear-induced entrainment and Rayleigh–Taylor piercing. It determines... Read more
Key finding: This numerical study comprehensively quantifies the outcomes of axisymmetric binary collisions between unequal-sized droplets governed by Weber, Ohnesorge numbers, and size ratio, revealing the dependency of ligament... Read more
Key finding: This work provides 3D CFD simulations of droplet deformation and breakup spanning bag, stamen, sheet-thinning regimes, employing symmetry assumptions validated by a full 3D simulation and an adaptive Eulerian method to track... Read more
2. What roles do interfacial rheology and viscosity contrast play in modulating drop breakup and post-breakup dynamics?
This theme focuses on the influence of interfacial viscosities, surface rheology (including shear and dilational surface viscosities), and viscosity ratio between drops and surrounding fluid on droplet deformation, stability, breakup behavior, and subsequent relaxation. The insights provide mechanistic understanding important for designing emulsions and microfluidic applications where interface properties are engineered to control droplet behavior.
Key finding: Direct numerical simulations show that increasing the droplet-to-carrier fluid viscosity ratio substantially decreases breakup rates in wall-bounded turbulence by damping internal turbulent fluctuations, analogous to higher... Read more
Key finding: The study experimentally and numerically demonstrates that non-uniform magnetic field gradients induce asymmetric deformation and breakup of ferrofluid droplets at microfluidic T-junctions, creating size-unequal daughter... Read more
Key finding: Numerical modeling coupled with microfluidic experiments reveals that hydrodynamic interactions between closely spaced drops lead to complex, periodic sequences of droplet breakup at micro-obstacles, with daughter drop... Read more
3. How can modeling frameworks encompassing energetic considerations and geometric constraints predict equilibrium drop configurations and breakup phenomena?
This research area addresses the development and application of theoretical and computational models incorporating interfacial energy, elastic strain energy, long-range potentials, and hydrodynamic interactions to characterize equilibrium morphologies, breakup thresholds, and fragmentation pathways of droplets or particles. By capturing the underlying physics, these models inform stability criteria, morphology transitions, and spatial distribution of fragments important for materials design and multiphase flow prediction.
Key finding: By augmenting Gamow’s liquid drop model with a long-range attractive background potential, the study restores minimizer existence for arbitrary mass and characterizes minimizer configurations in the small potential limit as... Read more
Key finding: Using a sharp interface level set model coupled with a smoothed extended finite element method, the paper predicts equilibrium morphologies of misfit particles considering elastic anisotropy and deformation-dependent... Read more
Key finding: The paper formulates a novel anthropological theory of breakage integrating postprocessualist and posthumanist critiques of human mastery over nature, conceptualizing breakage as uncontrollable unbinding phenomena. It... Read more
Key finding: This work proposes and validates a simple model predicting the time evolution of drop size distributions during drop breakup in stirred tanks. It relates maximum and minimum stable drop sizes to Weber and viscosity... Read more
Key finding: Experimental and analytical results demonstrate that droplets sliding on inclined hydrophobic surfaces can convert rotational momentum into linear momentum via deformation upon impact at downstream edges, enabling them to... Read more