Although bubble pinch-off is an archetype of a dynamical system evolving toward a singularity, it has always been described in idealized theoretical and experimental conditions. Here, we consider bubble pinch-off in a turbulent flow representative of natural conditions in the presence of strong and random perturbations, combining laboratory experiments, numerical simulations, and theoretical modeling. We show that the turbulence sets the initial conditions for pinch-off, namely the initial bubble shape and flow field, but after the pinch-off starts, the turbulent time at the neck scale becomes much slower than the pinching dynamics: The turbulence freezes. We show that the average neck size, d̅, can be described by d̅ ~ (t − t0)α, where t0 is the pinch-off or singularity time and α ≈ 0.5, in close agreement with the axisymmetric theory with no initial flow. While frozen, the turbulence can influence the pinch-off through the initial conditions. Neck shape oscillations described by a quasi-2-dimensional (quasi-2D) linear perturbation model are observed as are persistent eccentricities of the neck, which are related to the complex flow field induced by the deformed bubble shape. When turbulent stresses are less able to be counteracted by surface tension, a 3-dimensional (3D) kink-like structure develops in the neck, causing d̅ to escape its self-similar decrease. We identify the geometric controlling parameter that governs the appearance of these kink-like interfacial structures, which drive the collapse out of the self-similar route, governing both the likelihood of escaping the self-similar process and the time and length scale at which it occurs.


Mechanical and Aerospace Engineering


This work was supported by NSF Faculty Early Career Development (CAREER) Program Award Chemical, Bioengineering, Environmental and Transport Systems (CBET) 1844932 and American Chemical Society Petroleum Research Fund Grant 59697-DNI9 (to L.D.).

Keywords and Phrases

Interface; Self-similarity; Singularity; Turbulence

International Standard Serial Number (ISSN)

0027-8424; 1091-6490

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2019 The Authors, All rights reserved.

Publication Date

17 Dec 2019

PubMed ID