Hybrid Active/Passive Exhaust Nosie Control System (APECS) for Locomotives;Final rept. Dec 95-Sep 02

摘要

This report documents the analysis and development of an Active/Passive Exhaust Noise Control System (APECS) for railroad passenger locomotives that could provide at least 10 dBA noise reduction. Based on preliminary analyses and tests on actual locomotives in 1995 and 1996, a combination active roof-mounted system and a passive exhaust silencer were designed. The roof-mounted system consisted of ten enclosures, each with 2 12-inch speakers as actuators; eight microphones mounted on the roof as control sensors; a cabinet containing the controller and other electronics; a passive exhaust silencer specially designed for this system; and other components. As active liner system was also considered instead of the roof-mounted system; however, the latter was chosen since it could be built with commercially available and less costly components. This design was installed and tested on a locomotive in 1999. The tests included measurements of noise reduction performance and an inspection for any physical degradation of the system.