Analysis of possibilities for reducing noise inside a bus

The article addresses the issue of noise nuisance penetrating the interior of public transport vehicles such as buses. The analysis of the problem was based on a series of measurements taken at selected points in the vehicle. The paths of noise transmission into the vehicle interior were identified. Based on computer simulations, possible technical solutions aimed at reducing the noise level inside the bus were analyzed.Previous research conducted by the Department of Mechanics and Vibroacoustics team regarding noise inside A1012T and A0909L buses identified the penetration of noise from the operating power unit into the passenger compartment as the main problem.
This occurs directly from the engine compartment and indirectly through the luggage compartment. It was noted that in the case of indirect propagation, the relatively low sound insulation of the floor panel material is significant, especially since sound from the engine compartment to the luggage compartment is transmitted through an open-ended PVC pipe (electrical and control cable duct). The results obtained at that time regarding the elements constituting the interior equipment justified the conclusion that they are made of materials with sufficient damping of sound wave reflections.
In this case, the seats made of soft materials, which sufficiently dampen acoustic waves, are of decisive importance.
Further work on the problem of noise inside buses was conducted using simulation techniques based on the finite element method. (…)

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