Forces on and Stability of a Cylinder in a Wake

A model is developed for the steady fluid forces on a cylinder that is in the wake of a parallel, upstream cylinder in cross flow. The fluid forces are determined by correlating experimental data with an asymptotic model of the wake. This allows both lift and drag to be determined simply in closed form in terms of the single cylinder drag coefficient, the spacing of the two cylinders, and their diameters. The model is applied to static response and dynamic stability of an elastically mounted cylinders.