Virtual validation of a Metro rolling-stock for exterior and interior noise in standard controlled conditions

Validation of rolling-stock is a time and cost expensive task during the development of train. Replacing type tests by simulation (virtual validation) that fits the need of the complete railway industry in terms of accuracy and uncertainty, is possible in some cases. Simulation is widely used by train manufacturers during development of new products with good accuracy of prediction in a controlled environment as free field and ballasted track. Methodologies available are able to predict correctly in controlled conditions (ISO 3095/3381) interior and exterior noise for different operating conditions. In this paper, simulation cases will be presented for a standard metro product operating in controlled conditions. Simulations will be compared with experimental data for interior and exterior noise. Exterior noise modelling and propagation is done with analytical tools while interior noise is modeled using an experimental-numerical (beam-tracing) approach. Input data for simulations corresponds to numerical models of rolling noise and measured sound power level of equipment. Validation of the models are discussed and analyzed to confirm the reliability of virtual validation for rolling stock operating at controlled conditions. A proposal of a virtual validation approach based on uncertainties of the simulation is also discussed.