Noise Reduction of Working Ship and Marine Facilities

Abstract

In this paper, we outline a technique to estimate noise reduction effects and examples of having applied the noise reduction method on actual working ships and offshore drilling units. First, the technique to estimate the velocity levels of vibration sources was studied. A rigidly combined model and an isolator inserted model were used, and the experimental results were compared with the calculated results. Secondary, the vibration exciting source foundation characteristics of real ships were surveyed. A prediction method of the velocity level of vibration source foundation was clarified. The predicted values of the vibration velocity of the vibration source foundation deck were compared with the measured values. They show good agreement. Then the vibration isolation effect of isolator in the generator engine base of full-scale ship was grasped. Thirdly, vibration and noise isolation in accommodation spaces was taken up, using the floating floor technique, and elemental tests were carried out. The floating floor vibration reduction effect was verified by full-scale measurements.Finally, the appendix shows test results of impact sound of floors, model test results of sound isolation level between rooms and between rooms and outdoors to clarify the acoustic characteristics of living quarters and grasp the human living environment of accommodation spaces.