Scaling the hydrodynamic performance of heaving flexible panels

We present an experimental investigation of flexible panels actuated with heave oscillations at their leading edge. Our methods consist of kinematic video analysis, particle image velocimetry (PIV), and direct force measurements. Both the trailing edge amplitude and the mode shapes of the panel are found to scale with dimensionless ratios originating from the Euler-Bernoulli beam equation. Time-averaged thrust increases with heaving frequency, but also shows localized boosts around resonant frequencies where the trailing edge amplitude is maximized. For a constant heave amplitude, the time-averaged thrust coefficient is shown to be a function of Strouhal number over a wide range of conditions. Instantaneous thrust shows two peaks per oscillation cycle, occurring during the mid up- and down-stroke of the leading edge.