Orbital flow past two revolving circular cylinders at low reynolds number: A numerical study

Abstract The study presents the vortex shedding and force coefficients for a system of two revolving cylinders, diameter (D) at Reynolds number (Re) equal to 100. The outer cylinder orbits the inner cylinder while the inner cylinder rotates on its own axis. The effect of varying Keulegan-Carpenter number ( K = 2 π ∙ U ∞ ω ∙ D ) is studied for a fixed center-to-center distance of the cylinders (L) = 4D as illustrated in Fig. 1 . The numerical study has been carried out using ANSYS Fluent. For higher values of K , the inertial force of the free stream is the dominating force on the cylinders. For lower K values, the drag force on the outer cylinder is dominating the flow properties. For intermediate values of K , the vortex of the outer cylinder folds in the region between the cylinders. There is a critical value K = Kc which tips the dominating force from inertial force to drag force of the revolving cylinder.