Drift Due to Two Obstacles in Different Arrangements
Abstract
We study the drift induced by the passage of two cylinders through an
unbounded extent of inviscid incompressible fluid under the assumption that the
flow is two-dimensional and steady in the moving frame of reference. The goal
is to assess how the resulting total particle drift depends on the parameters
of the geometric configuration, namely, the distance between the cylinders and
their angle with respect to the direction of translation. This problem is
studied by numerically computing, for different cylinder configurations, the
trajectories of particles starting at various initial locations. The velocity
field used in these computations is expressed in closed form using methods of
the complex function theory and the accuracy of calculations is carefully
verified. We identify cylinder configurations which result in increased and
decreased drift with respect to the reference case when the two cylinders are
separated by an infinite distance. Particle trajectories shed additional light
on the hydrodynamic interactions between the cylinders in configurations
resulting in different drift values. This ensemble of results provides insights
about the accuracy of models used to study biogenic transport.