Steady outer-flow boundary conditions for incompressible unsteady two-dimensional flows past bluff bodies on an unbounded domain

A new "far-field" computational boundary condition for use in unsteady two-dimensional bluff-body flows is presented. At a given Reynolds number, we impose the steady-flow solution on the upstream and lateral boundaries, providing higher accuracy than conventional far-field boundary conditions imposed on the same domain. Alternatively, for a solution of specified accuracy, this approach allows use of a considerably smaller computational domain. The approach, which reduces the effects of "blockage" for any finite domain, is illustrated for vortex shedding by a circular and square cylinders.