Migration of rigid spheres in a two-dimensional unidirectional shear flow of a second-order fluid
نویسنده
چکیده
The lateral migration of a neutrally buoyant rigid sphere suspended in a secondorder fluid is studied theoretically for unidirectional two-dimensional flows. The results demonstrate the existence of migration induced by normal stresses whenever there is a lateral variation of the shear rate in the undisturbed flow. The migration occurs in the direction of decreasing absolute shear rate, which is towards the centre-line for a plane Poiseuille flow and towards the outer cylinder wall for Couette flow. The direction of migration agrees with existing experimental data for a viscoelastic suspending fluid, and qualitative agreement is found between the theoretically predicted and experimentally measured sphere trajectories.
منابع مشابه
A note on the motion of a spherical particle in a general quadratic flow of a second-order fluid
The migration of a rigid sphere in a two-dimensional unidirectional shear flow of a second-order fluid was considered by Ho & Leal (1976). It was found that the sphere would migrate in the direction of decreasing absolute shear rate. The present paper extends the previous results to a general quadratic flow, and also considers the case of a spherical drop.
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