STRUCTURAL CONFIGURATION AND ACOUSTICAL PERFORMANCE OF ENGINE EXHAUST MUFFLERS FOR CONSTRUCTION EQUIPMENT AND MACHINERY
Keywords:Noise emission; engine exhaust muffler; construction equipment and machinery; sound transmission loss.
The main objective of the present work is to characterize numerically the link between the geometrical parameters and the functional noise reduction properties of typical engine exhaust mufflers for construction equipment and machinery. To this regard, the acoustical modeling of these devices is first presented using the finite element approach. Then, we investigate the effects of both the geometrical parameters and the shape configuration of some typical mufflers (e.g., chambered, turbo, reactive, absorptive…) on their sound transmission loss. In terms of acoustics, for a given total length (600 mm), mufflers show a better acoustic performance (up to 50 dB) with a high number of chambers/partitions or using absorbing layers, especially micro-perforated panel with hole size of 24 mm and its fraction 48% can improve the sound transmission loss up to 100 dB at low frequency less than 1 kHz. The obtained results show clearly that the noise reduction target could be successfully achieved over an individual octave band or the whole frequency range by tuning structures of appropriate engine exhaust mufflers.