The segregation of sheared binary fluids in the Bray-Humayun model

The phase separation process which follows a sudden quench inside the coexistence region is considered for a binary fluid subjected to an applied shear flow. This issue is studied in the framework of the convection-diffusion equation based on a Ginzburg-Landau free energy functional in the approximation scheme introduced by Bray and Humayun [Phys.Rev.Lett. 68, 1559, (1992)]. After an early stage where domains form and shear effects become effective the system enters a scaling regime where the typical domains sizes L‖, L⊥ along the flow and perpendicular to it grow as t5/4 and t1/4. The structure factor is characterized by the existence of four peaks, similarly to previous theoretical and experimental observations, and by exponential tails at large wavevectors. 47.20.Hw; 05.70.Ln; 83.50.Ax Typeset using REVTEX 1