Rapid engineering assessment method for acoustic design of metro trains

The low noise design must be embedded in every design phase of the train vehicles. The vehicle noise calculation models are established by taking full account of vehicle geometrical dimensions, measuring point location, noise sources, sound insulation and sound absorption. These models can (1) complete quantitative assessment of acoustic structures and noise sources of the vehicles to achieve the top-down quantitative control of acoustic index; (2) calculate interior noise and exterior noise under static conditions, running conditions, as well as tunnel environment conditions; (3) calculate and analyze noise limit values of main noise sources when the sound insulation of walls have been given, such as floor, side wall and gangway; and (4) calculate and analyze sound insulation limit values when the sound power of main noise sources have been given. The average differences between the A-weighted measured and predicted levels are less than 2 dB. The models show a very important guiding role for quantitative acoustics design of metro trains.