caa a22 4500 605466823 CHVBK 20210128100309.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00397-015-0885-4 doi (NATIONALLICENCE)springer-10.1007/s00397-015-0885-4 Emulsion rheology for steady and oscillatory shear flows at moderate and high viscosity ratio [Elektronische Daten] [T. Oliveira, F. Cunha] A numerical simulation scheme based on a three-dimensional boundary integral method is used for the purpose of estimating the macroscopic flow from the microscale drop deformation for emulsions of high viscosity ratio under steady, oscillatory shear, and extensional flows. The effects of drop deformation and shear rate are examined for moderate and high viscosity ratio. The accuracy and convergence of the numerical simulations is illustrated by comparing drop deformation and rheology with experimental observations and an asymptotic theory based on a second-order small deformation theory also developed in this work. We also examine an emulsion undergoing a pure extensional flow and an extensional viscosity of the emulsion is computed by the theory and the numerical simulations. In addition, we also explore regimes of linear and nonlinear viscoelasticity when the emulsion is subjected to oscillatory shear for different viscosity ratio. Emulsion Fourier modes are examined for two different viscosity ratio. For a more concentrate emulsion with an unit viscosity ratio, a static shear elastic modulus is computed as a function of drop volume fraction and compared with experimental data. The numerical simulation results are validated against theory and experimental observation of drops in shear and extensional flows. A very good agreement is observed for moderate and high viscosity ratio. The regime of emulsions with relatively high viscosity ratios has not been much explored in the current theoretical and experimental literature. The boundary integral numerical simulations developed in this work has the ability to predict what we expect on the behavior of emulsion with moderate and high viscosity ratio. Springer-Verlag Berlin Heidelberg, 2015 Drop nationallicence Rheology nationallicence Emulsion flows nationallicence Boundary integral method nationallicence High viscosity ratio nationallicence Oscillatory shear nationallicence Oliveira T. University of Brasilia, Department of Mechanical Engineering, 70910 900, Brasilia-DF, Brazil aut Cunha F. University of Brasilia, Department of Mechanical Engineering, Laboratory of Microhydrodynamic and Rheology - VORTEX, 70910 900, Brasilia-DF, Brazil aut Rheologica Acta Springer Berlin Heidelberg 54/11-12(2015-12-01), 951-971 0035-4511 54:11-12<951 2015 54 397 https://doi.org/10.1007/s00397-015-0885-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00397-015-0885-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Oliveira T. University of Brasilia, Department of Mechanical Engineering, 70910 900, Brasilia-DF, Brazil aut NATIONALLICENCE 700 1- Cunha F. University of Brasilia, Department of Mechanical Engineering, Laboratory of Microhydrodynamic and Rheology - VORTEX, 70910 900, Brasilia-DF, Brazil aut NATIONALLICENCE 773 0- Rheologica Acta Springer Berlin Heidelberg 54/11-12(2015-12-01), 951-971 0035-4511 54:11-12<951 2015 54 397