Acoustic Enclosure Optimization for a Higher Capacity Diesel Generator Set Using Statistical Energy Analysis (SEA) Based Approach

Diesel powered electric generators are used in a variety of applications, such as emergency back-up power, temporary primary power at industrial facilities, etc. As regulatory and customer requirements demand quieter designs, special attention is given to the design of acoustic enclosures to balance the need of noise control with other performance criteria like ventilation and physical protection. In the present work, Statistical Energy Analysis (SEA) approach augmented by experimental inputs is used to carry out Vibro-acoustic analysis of an enclosure for higher capacity Diesel generator set. The exterior sound radiated from an enclosed generator is predicted and further enclosure is optimized for an improved sound-suppression. The airborne sources such as engine, alternator, radiator fan and exhaust are modelled explicitly using experimental noise source characterization. Structure borne inputs are also captured in the test for improving modelling accuracy. The vibroacoustic performance of the enclosure and sound absorbers are modelled through Biot parameters and experimentally validated with a good agreement between test and simulated results within 2 dB for overall levels. Further, path contribution and sensitivity analysis has been done on base enclosure to find out major contributors to exterior radiated noise. Optimization is done using parameters like: noise path modifications (ducts, partitions), leakage minimization and acoustic louver designing based on preceding analysis results. Optimized enclosure has resulted in 3 dB reduction in overall noise level