Energy harvesting with a rotating cylinder pair in a free-stream flow

We present numerical simulations of a cylinder pair placed orthogonally to a uniform parallel flow at a Reynolds number of O(100). The cylinder pair's rotation is driven by the incoming flow and energy harvesting is modeled by applying an external torque proportional to each cylinder's rotational velocity. For a given cylinder spacing, this problem is described by two non-dimensional parameters: the Reynolds number and the non-dimensional damping coefficient. We perform a set of simulations to compute the average power generated as a function of these two parameters, and compare against other approaches. The results provide insight into the use of viscous-based power generation mechanisms at intermediate Reynolds numbers.