Transitions in rotations of a nonspherical particle in a three-dimensional moderate Reynolds number Couette flow

The rotational states of three-dimensional nonspherical particles including cylindrical and disk-shaped, as well as prolate and oblate, ellipsoidal in a Couette flow are studied by using a lattice Boltzmann simulation. We discover that rotation of a nonspherical particle exhibits several different states, depending on the ranges of the particle Reynolds numbers and the geometric shape of the particle. As the Reynolds number increases, the rotation transits from one state to another state.