| 摘要 |
PURPOSE:To detect the underwater noises in the vicinity of the outer plating of the bottom of a ship, by forming an inverted funnel shaped space in the inner side of the outer plating of the bottom of the ship, filling a liquid, whose intrinsic acoustic impedance is equal to the external water, in the space, preventing the vibration of the hull to said liquid, and using an underwater microphone, which is inserted in the space. CONSTITUTION:In order to detect underwater noises, at first, liquid L, whose intrinsic acoustic impedance becomes equal to outer water (sea water), e,g., sea water, castor oil, or the like, is injected in an inverted funnel shaped space 3, which is formed by a main body 1 of a device of a detecting apparatus S at the inner side of an outer plating 2 of a hull. Then, only the underwater radiation noises in the vicinity of the apparatus S are transmitted to the liquid L in inspection. At this time, the vibration of the hull of the ship is absorbed by a vibration controlling member 4. Therefore, only the underwater radiation noises are transmitted without attenuation. The underwater radiation noises transmitted to the liquid L are propagated to an underwater microphone 5, which is provided in the space 3 without resistance, and the noises can be detected efficiently. |
