Countermeasure for the Noise of Main Engine in Vessel : Design of Exhaust Gas Muffler

Abstract

With the recent tendency to build high speed vessels high powered enginers are installed, and diesel engines are more frequently used than before to meet economic demand. But, one of the problems encountered in the installation of diesel engines is that of reducing the intake noise and exhaust gas noise to acceptable values. Specially the exhaust gas noise is increased with the power up of main engine and affects the surrounding bridge area. Exhaust gas noise has low frequency, peculiar to the large engines, and in some cases the noise exceeds the acceptable values. Although the spectra of the noise which is to be diminished must be thoroughly examined prior to the designing of exhaust gas muffler, such examination has not been extensively made, so that no muffler up to this day has been quite effective. In view of the above situation, spectra of the exhaust gas noise were measured on board and an exhaust gas muffler has been attempted to meet the characteristics revealed by the model tests.