in Time-dependent Shear Flow by

This thesis presents a three-dimensional numerical study on the dynamics of deformable capsules in sinusoidally oscillating shear flow. For this study, we consider capsules of spherical and oblate spheroid resting shapes. For spheri-cal resting shapes, we find identical deformation response during positive and negative vorticity. However, the deformation response becomes unequal and shows complex behavior for nonspherical resting shapes. The average elonga-tion is higher in the retarding phase of the shear flow than in the accelerating phase. Primarily two types of dynamics are observed for nonspherical shapes: a clockwise/counter-clockwise swinging motion in response to the altering flow ii direction that occurs at both high and low values of shear rate amplitudes, and a continuous/unidirectional tumbling motion that occurs at intermediate values. The unidirectional tumbling motion occurs despite the fact that the time-average vorticity is zero. Such a tumbling motion is accompanied by a continuous tank-treading motion of the membrane in the opposite direction. We obtain phas