Abstract
In this paper. the characteristics of the wave control were investigate for the case of the multi-span type using the flexible sheet with many springs on both sides. Consequently. the coefficient of transmitted wave becomes sufficiently small in the case of multi-span type that of one sheet. It was found that the multi-span type had excellent effect for the wave control. Nextly, the magnitude of vortex which was generated around the flexible sheet was measured visually using the video-system. Relation between a quantity of vortex and energy loss was discussed.
