Sustainable Acoustics for Powertrain Noise Reduction

A common way to reduce the noise of automotive powertrains, both with internal combustion engine (ICE) and electric driveline, is to cover their noise radiating areas. However, the parts used for this purpose, besides being effective from the NVH standpoint, also have to fulfil several non-NVH requirements. For ICE, they have to provide a certain level of thermal insulation while favoring the reduction of fuel consumption and CO2 emissions. For electric powertrains, lightweight, environmental footprint and sustainability become preponderant in the design of engine covers. Combining these multidimensional requirements, a new fiber-based mono-material product for engine-mounted applications is proposed. It is able to provide optimum noise protection in the passenger cabin and greater driving comfort while keeping high level of sustainability, good heat resistance and relatively low weight. This paper deals with the acoustic benchmarking of the newly developed product against various more traditional solutions available on the market. Using an experimental approach, the newly developed solution is positioned against the other bills of materials, in terms of acoustic absorption and insulation performance first at material level. Then, an acoustic performance comparison is carried out at part level on an electric motor mock-up.