| 摘要 |
In order to reduce the emission of noise from a windmill, its glass fibre blades (1) according to the invention are produced with a shell (2) of a laminate which incorporates one or more layers of thin rubber sheeting (3). The natural vibration in the shell (2) is hereby suppressed, in that the separated layers will serve as mutual damping elements. To further suppress the waves inherent in the air in the cavity or cavities (6) in the shell (2), the cavity or cavities are filled with a loose filling material (7) of polystyrene balls or the like. The waves inherent in the cavity or cavities are hereby eliminated, while at the same time the centrifugal force will press the filling material (7) out against the internal walls of the shell, whereby its vibrations are effectively suppressed. |
