| 摘要 |
PURPOSE:To prevent the occurrence of noise by eliminating resonance by using a rubber dam in which projections are provided on the surface of water at an inerval L in the longwise direction of a rubber dam and the ratio of the distance L to the height H of the risen rubber dam is designated to L/H<=7.5. CONSTITUTION:Since the length of an overflow 3a, or a space 4, is cut every interval L and the volume of the space is thus smaller than in the conventional cases, no resonance with the vibration of water flow occurs, and therefore, the increase in the noise of overflow can be avoided. |
