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Ohta-Jasnow-Kawasaki Approximation for Nonconserved Coarsening under Shear

Andrea Cavagna·Alan J. Bray·Rui D. M. Travasso
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Abstract

We analytically study coarsening dynamics in a system with nonconserved scalar order parameter, when a uniform time-independent shear flow is present. We use an anisotropic version of the Ohta-Jasnow-Kawasaki approximation to calculate the growth exponents in two and three dimensions: for d=3 the exponents we find are the same as expected on the basis of simple scaling arguments, that is 3/2 in the flow direction and 1/2 in all the other directions, while for d=2 we find an unusual behavior, in that the domains experience an unlimited narrowing for very large times and a nontrivial dynamical scaling appears. In addition, we consider the case where an oscillatory shear is applied to a two-dimensional system, finding in this case a standard t^1/2 growth, modulated by periodic oscillations. We support our two-dimensional results by means of numerical simulations and we propose to test our predictions by experiments on twisted nematic liquid crystals.

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Andrea Cavagna, Alan J. Bray, Rui D. M. Travasso. 2000-07-27. Ohta-Jasnow-Kawasaki Approximation for Nonconserved Coarsening under Shear. https://doi.org/10.1103/physreve.62.4702

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