2) The acoustic behavior was analyzed in detail by the numerical simulation program SYSNOISE. As a result, it clarified the point that the arrangement of exhaust pipe and the location of the speaker affect the performance and efficiency of noise reduction significantly.
3) By optimizing the length of the exhaust pipe and the secondary speaker pipe, the AENC system could be applied to various speed engines, such as the main engine for marine use.
4) By optimizing arrangement of the secondary speaker pipe, only one speaker AENC system can be applied to the constant speed engine, such as anxiously engine for marine use.
5) By adding the signal filters to the input signals of the microphones, the remaining noise spectrum could be controlled.
6) Finally, an actual active exhaust cancellation system was developed. As a result, the exhaust noise level could be reduced by the amount of more than 20dB(A). Also, the occupied space of the system was 50% less than that of the passive silencer with the same noise reduction level.
References
1) T. Yonezawa et al, "Development of Low Noise Engine for Nautical Training Sail Ship 'KAIOUMARU"', CIMAC 1993 D48.
2) T. Yonezawa et al, "Development of Elastic Mounting System for Medium and Low Speed Main Diesel Engine for Marine Use" ISME 1995, Vol.2, pp.1.
3) K. Ishino et al, "Active noise control for gas engine for cogeneration use", Proceeding of JSME No.930-42. Vol.B, pp.121, (In Japanese).
4) Y. Hayashi et al "Active Nirse Control for Exhaust Noise of Diesel Engines". ISME 1995. Vol.2, pp.74.
5) E. Arnold et al, "Development of a Prototype Active Muffler for the Detroit Diesel 6V-92 TA Industrial Engine", SAE 911045.
6) T. Mikami et al, "The Development of Electronic Noise Cancellation System for Duct", Hitachi Hyoron, Vol.71, No.5 (1989-5), pp.123, (In Japanese).
7) LEUVEN MEASUREMENT SYSTEM, "SYSNOISE Theoretical Manual".
