摘要 |
The present invention relates to a method and apparatus for oscillating a foil in a fluid. The method according to the invention comprises the steps of —generating an oscillating heave motion of the foil in the fluid, the oscillation cycle of the heave motion consisting of two strokes of the foil in opposite direction; —generating an oscillating pitching motion of the foil in the fluid; characterized by —controlling the heave motion; and —adjusting the pitch during the oscillation cycle of the heave motion; such that —over 65% to 85% of the oscillation cycle of the heave motion, for each stroke of the foil, the absolute angle of attack is more than 60% of the maximum absolute angle of attack during the stroke. |