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Vela-Martín A, Avila M. Memoryless drop breakup in turbulence. SCIENCE ADVANCES 2022; 8:eabp9561. [PMID: 36525489 PMCID: PMC9757738 DOI: 10.1126/sciadv.abp9561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
The breakup of drops and bubbles in turbulent fluids is a key mechanism in many environmental and engineering processes. Even in the well-studied dilute case, quantitative descriptions of drop fragmentation remain elusive, and empirical models continue to proliferate. We here investigate drop breakup by leveraging a novel computer code, which enables the generation of ensembles of experiments with thousands of independent, fully resolved simulations. We show that in homogeneous isotropic turbulence breakup is a memoryless process whose rate depends only on the Weber number. A simple model based on the computed breakup rates can accurately predict experimental measurements and demonstrates that dilute emulsions evolve through a continuous fragmentation process with exponentially increasing time scales. Our results suggest a nonvanishing breakup rate below the critical Kolmogorov-Hinze diameter, challenging the current paradigm of inertial drop fragmentation.
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Affiliation(s)
- Alberto Vela-Martín
- Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Bremen 28359, Germany
| | - Marc Avila
- Center of Applied Space Technology and Microgravity (ZARM), University of Bremen, Bremen 28359, Germany
- MAPEX Center for Materials and Processes, University of Bremen, Bremen 28359, Germany
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Olad P, Innings F, Crialesi-Esposito M, Brandt L, Håkansson A. Comparison of turbulent drop breakup in an emulsification device and homogeneous isotropic turbulence: insights from numerical experiments. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.130569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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The Role of Stochastic Time-Variations in Turbulent Stresses When Predicting Drop Breakup—A Review of Modelling Approaches. Processes (Basel) 2021. [DOI: 10.3390/pr9111904] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Many industrially relevant emulsification devices are of the high-energy type, where drop deformation and subsequent breakup, take place due to intense turbulent fluid–drop interactions. This includes high-pressure homogenizers as well as rotor-stator mixers (also known as high-shear mixers) of various designs. The stress acting on a drop in a turbulent flow field varies over time, occasionally reaching values far exceeding its time-averaged value, but only during limited stretches of time, after which it decreases down to low values again. This it is one factor separating turbulent from laminar emulsification. This contribution reviews attempts to take this intermittently time-varying stress into account in models predicting the characteristic drop diameter resulting from emulsification experiments, focusing on industrially applicable emulsification devices. Two main frameworks are discussed: the Kolmogorov–Hinze framework and the oscillatory resonance framework. Modelling suggestions are critically discussed and compared, with the intention to answer how critical it is to correctly capture this time-varying stress in emulsification modelling. The review is concluded by a list of suggestions for future investigations.
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Shuai Y, Wang X, Huang Z, Sun J, Yang Y, Liao Z, Wang J, Yang Y. Experimental measurement of bubble breakup in a jet bubbling reactor. AIChE J 2020. [DOI: 10.1002/aic.17062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Yun Shuai
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
| | - Xinyan Wang
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
| | - Zhengliang Huang
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
| | - Jingyuan Sun
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
| | - Yao Yang
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
| | - Zuwei Liao
- State Key Laboratory of Chemical Engineering College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
| | - Jingdai Wang
- State Key Laboratory of Chemical Engineering College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
| | - Yongrong Yang
- State Key Laboratory of Chemical Engineering College of Chemical and Biological Engineering, Zhejiang University Hangzhou People's Republic of China
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Abi Chebel N, Piedfert A, Lalanne B, Dalmazzone C, Noïk C, Masbernat O, Risso F. Interfacial Dynamics and Rheology of a Crude-Oil Droplet Oscillating in Water at a High Frequency. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:9441-9455. [PMID: 31257882 DOI: 10.1021/acs.langmuir.9b01594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report investigations of a pendant diluted crude-oil droplet in water that is forced to oscillate at a frequency ω. The droplet interface contains a significant amount of surface-active agents and displays a marked viscoelastic rheology with elastic moduli larger than viscous ones. At a low frequency, fluid viscosity and inertia are negligible, which allows a direct determination of the dilatational interface rheology. At a large frequency, eigenmodes of inertial shape oscillations are excited. By decomposing the interface shape into spherical harmonics, the resonance curves of the inertial modes of the interface are determined, as well as the frequency and damping rate of each mode. These two parameters are of major importance for the prediction of the deformation and breakup of a droplet in any unsteady flow without any prior knowledge of either the chemical composition or the detailed rheological properties of the interface. Then, interfacial rheology is related to interface dynamics by solving the coupled dynamic equations for the two fluids and the interface. It turns out that the rheology of the interface is well described by an equivalent two-dimensional viscoelastic material, the elasticities and viscosities of which depend upon the frequency. A first significant result is that shear and dilatational elasticities are closely connected, as are shear and dilatational viscosities. This implies that intrinsic rheology plays a major role and that compositional rheology is either negligible or strongly coupled to the intrinsic one. A second major result is that, for moderately aged droplets (≤5000 s), the elasticity and viscosity at a high frequency (10-80 Hz) can be extrapolated from low-frequency measurements (≤1 Hz) by a simple power law of the frequency, ωz. The exponent z is related to the loss angle θloss by a relation found in many previous low-frequency investigations of crude-oil interfaces: z = θloss/2π. The present work thus extends classic observations obtained at a low frequency to a higher frequency range corresponding to the natural frequency of the droplets, where the droplet shape results from the balance between dynamic pressure and surface stresses and the interface involves simultaneous shear and dilatation. These results bring about serious constraints regarding the modeling of physicochemical underlying mechanisms and provide some insights for the understanding of the structure of crude-oil interfaces.
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Affiliation(s)
- Nicolas Abi Chebel
- Institut de Mécanique des Fluides de Toulouse (IMFT), Université de Toulouse, CNRS , 31400 Toulouse , France
- Laboratoire de Génie Chimique (LGC), Université de Toulouse, CNRS , 31432 Toulouse , France
- FR FERMAT, Université de Toulouse, CNRS, INPT, INSA, UPS , Toulouse , France
| | - Antoine Piedfert
- Institut de Mécanique des Fluides de Toulouse (IMFT), Université de Toulouse, CNRS , 31400 Toulouse , France
- Laboratoire de Génie Chimique (LGC), Université de Toulouse, CNRS , 31432 Toulouse , France
- FR FERMAT, Université de Toulouse, CNRS, INPT, INSA, UPS , Toulouse , France
| | - Benjamin Lalanne
- Laboratoire de Génie Chimique (LGC), Université de Toulouse, CNRS , 31432 Toulouse , France
- FR FERMAT, Université de Toulouse, CNRS, INPT, INSA, UPS , Toulouse , France
| | - Christine Dalmazzone
- IFP Energies nouvelles , 1-4 avenue de Bois Préau , 92852 Rueil-Malmaison , France
| | - Christine Noïk
- IFP Energies nouvelles , 1-4 avenue de Bois Préau , 92852 Rueil-Malmaison , France
| | - Olivier Masbernat
- Laboratoire de Génie Chimique (LGC), Université de Toulouse, CNRS , 31432 Toulouse , France
- FR FERMAT, Université de Toulouse, CNRS, INPT, INSA, UPS , Toulouse , France
| | - Frédéric Risso
- Institut de Mécanique des Fluides de Toulouse (IMFT), Université de Toulouse, CNRS , 31400 Toulouse , France
- FR FERMAT, Université de Toulouse, CNRS, INPT, INSA, UPS , Toulouse , France
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