The effect of thixotropy on deformation of a single droplet under simple shear flow

Abstract

In this paper, the deformation of an isolated single two-dimensional droplet under simple shear flow is studied regarding the thixotropic behavior. In doing so, a modified consistent weakly compressible smoothed particle hydrodynamics method is employed. It is assumed that the thixotropic fluid obeys the Moore model, and the surface tension is modeled by the continuum surface tension (CST) method. After verifying the utilized paradigm, it is applied to novel cases in which one of the fluids exhibits thixotropic behavior. The effects of Moore's model constants are examined through several numerical simulations. It is shown that the drop deformation is dramatically affected by thixotropic behavior. Generally speaking, the deformation of the Newtonian droplet is decreased by increasing the destruction-to-rebuild ratio of the surrounding thixotropic liquid. The same trend is found when the thixotropic droplet is exposed to the shear flow of a Newtonian fluid. Also, it is demonstrated that the presence of another droplet in the vicinity of the first droplet could dramatically change the flow domain. To the best of the author's knowledge, the effect of thixotropy is investigated on droplet deformation for the first time.