Integrating experiments into an energy-based reduced-order model for vortex-induced-vibrations of a cylinder mounted as an inverted pendulum

High-resolution digital particle image velocimetry has been used to measure fluid energy transport terms necessary for developing a scientifically rigorous Hamiltonʹs Principle approach to modelling fluid–structure interactions. The interaction being modelled is the vortex-induced vibration of a low mass-damping circular cylinder mounted like an inverted pendulum in a water tunnel. Data in this paper are specifically focussed on the case where the cylinder undergoes large amplitude modulated oscillations slightly below the cylinderʹs natural frequency. This paper describes the experimental methodology used to acquire key modelling data, i.e. kinetic energy transport and work by viscous forces across the boundaries of an integral control volume. Integration of these data into the coupled energy equation is also described. The ability of this modelling approach to accurately capture complex phenomena such as beating is demonstrated.