Computation of unsteady flow past an oscillating cylinder near a vertical wall

Abstract

Some flowfields involve multiple bodies with at least one of the components in relative motion with respect to the others. Because of the inherent dynamic interference, the generated unsteady flowfield displays features significantly different than that around a static body. With this motivation, a computational method called kinematic domain decomposition is developed to simulate an unsteady flow past moving bodies and their aerodynamic interference. The inviscid equations governing the flowfield and the dynamics equations governing the rigid-body motion are solved simultaneously on decomposed computational domains. The subdomain grids can move with respect to and communicate with each other. Initially, the method is validated by comparing its results with the experimental data for a pitching airfoil. Then, the method is demonstrated for flows past a cylinder that is pitched sinusoidally near a static vertical wall. The results indicate a stronger interference for a subsonic flowfield than a supersonic flowfield. By contrasting these dynamic flowfields with that of a static cylinder, effects of the dynamics on the interference features are shown. It is concluded that performing a number of sequential steadystate computations is not adequate for a flowfield around an object in relative motion near another object.