In this letter we show that a cylinder oscillating harmonically in line with an incoming flow at a frequency equal to the natural frequency of vortex shedding induces for certain amplitudes of oscillation a chaotic state in the flow, characterized by an aperiodic lift force. The result is obtained through numerical simulation of the Navier–Stokes equations for two-dimensional flow. The chaos is attributed to the competition between two modes: the natural mode of the wake and the mode forced by the moving cylinder, which have entirely different spatial structures.
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2009
American Institute of Physics
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