Noise emission from alternative fuel vehicles: Study case

Noise pollution has become a source of social tension, with economic development on one hand and quality of life on the other. The number of vehicles on the road is increasing constantly, especially in urban areas. As a consequence, environmental pollution has also increased, not only due to fuel emissions harmful to people, but also due to noise pollution; therefore, the control of the acoustic environment has turned out to be a key issue and a technological challenge. According to Ibarra et al. there have been recent studies on the quantification and characterization of noise emitted by vehicles in the near and far fields, but this kind of work has mainly been developed for internal combustion vehicles fuelled by diesel or petrol. With new emerging technologies aimed at improving world social and environmental conditions, new alternative fuel vehicles are appearing around the world, especially in large cities. These new vehicles have not yet been characterized regarding their noise emissions. The aim of this work is to characterize and quantify the level of noise emitted by alternative fuel vehicles, such as hybrid and electric vehicles, for both near and far fields. To achieve this, it would be very useful to incorporate simulations of noise mapping. Experimental results of this work demonstrate that hybrid and electric engines have made important contributions towards reducing engine noise in suburban and urban traffic, at least 10 dBA less than diesel or petrol vehicles; however, noise from the tyre-ground interaction remains the main source of noise, especially in suburban roads at high speeds.