Technique Research Of Reducing Noise Inside Railway Passenger Cars

The train is one kind of the main conveyances that is safe, economical and efficient. But interior noise of a passenger compartment disturbs passengers' rest. To reduce interior noise, many countries take effective measures e.g. Japan, France and Germany. China is under way in the field.The characteristics of noise are topical and temporary. All kinds of methods measuring noise have been produced and A-weighting sound level is extensively used as a kind of fundamental measure in all of the world. Any one of noise pollution occurrences includes the three constituents that are a noise source, a propagation route and an accepter. To reduce interior noise of a passenger compartment measures are taken in the propagation route and the accepter. It is effective that railroad line and structure of railway carriage are improved on and acoustical absorption and sound insulation materials are selected reasonably.The major noise resources of high-speed railway vehicles (v 200km/h) are wheel-rail rolling noise, structure noise, aerodynamic noise and collector system noise. The major noise sources of low-speed railway vehicles (v 200km/h) running in domestic existing lines are wheel-rail rolling and structure noise. For designing railway vehicle with lower noise, interior noise is measured in the cushioned berth sleeping car. Measurement points include: over floor corresponding to the center of bogie truck, air return port, air feeding port, over coupler and draft gear, Head acoustics measurement and analysis system is used in signal capture and data process. The paper produces noise reduction measurements and major frequency coverage that is 200~2kHz to be used in selection of acoustical absorption and sound insulation materials. The measurement produces self-contained data to design lower noise railway vehicles in the future.