International Shipbuilding Progress · 1995 · 56 citations · 0 references
EngineeringMechanical EngineeringComputational Fluid DynamicsPropulsionVibrationPropulsion ControlPropulsion EfficiencyLarge-amplitude OscillationsOscillating AirfoilsOscillatory MotionPropulsive CoefficientPropulsive EfficiencyPropulsive Efficiency PredictionThrust Coefficient
The study examines flexible oscillating NACA 0012 foils near a favorable operating point. A 2‑D time‑domain constant‑potential panel method was employed to analyze chordwise flexible oscillating hydrofoils as propulsors. Large‑amplitude oscillations and chordwise deflections produced propulsive thrust and efficiency that peaked for each motion parameter, with efficiency most sensitive to heave amplitude/chord ratio, pitch amplitude, and phase, and less to pitching axis position and flexibility.
A two-dimensional time-domain constant potential panel method was used for analysis of chordwise flexible oscillating hydrofoils as oscillating propulsors. The oscillatory motions as well as the chordwise deflections were of large amplitude. Results are presented of propulsive thrust coefficient and efficiency over ranges of motion parameters including varied reduced frequency, pitch amplitude and feathering parameter; heave amplitude/chord ratio; pitching axis position; phase between pitching and heaving motions; and deflected shape. The ranges were taken about a favourable operating point for a flexible oscillating NACA 0012 foil. A peak in propulsive efficiency was found for each motion parameter variation studied. Propulsive efficiency varied strongly with changes in heave amplitude/chord ratio, pitch amplitude and phase between heaving and pitching motions, but less strongly for variations in pitching axis position and flexibility.