Arbitrarily shaped particles in shear flow

Particle motion in shear flow plays an important role in many industrial as well as biomedical applications. In order to study the motion of differently shaped particles within a shear flow, the incompressible Navier-Stokes and the rigid-body-dynamics equations are solved coupled together by means of an implicit iterative approach. An immersed boundary method is used to take into account the presence of moving particles within the fluid domain, without having to regenerate or deform the computational grid. The method has been validated at first by computing flows past a fixed and an oscillating circular cylinder at various values of the Reynolds number (Re). Then, the motion of three differently shaped particles immersed within a low-Re Couette and planar Poiseuille flow has been studied to ascertain their lateral migration and orientation behavior: Regardless of their initial position, the neutrally buoyant particles are observed to migrate toward an equilibrium position, depending on the type of the flow. Finally, numerical solutions are presented to understand the influence of increasing Re upon the lateral migration and orientation behavior of the elliptic particle immersed in a Couette flow