To reach the aforementioned aim of TRANSIT, five high level objectives have been specified. These five high level objectives have been mapped onto 6 work packages. In section 1.2 the work carried out per work package is presented, this section will continue with an update in the context of the high level objectives.
Reduce rail vehicle noise certification lead time and costs, and lower operator’s track occupation requirement for testing by providing accurate virtual certification tools. Validated procedures for source characterization have been developed and tested on generic sources. Together with FINE-2, two additional test objects have been selected, and characterized. Different calculation models for these tools have been compared. [WP1]
Reduce the need for a TSI-compliant track by developing and demonstrating accurate separation and transposition techniques. Separation methods (PBA-based, TWINS-based and ATPA-based) have been enhanced, tested at MdM and in measurement campaigns with FINE-2. Successful tests for separating track and wheel contributions for the various test vehicle, as well as wheel/rail roughness separation. Transposition techniques have been assessed with a positive outcome. [WP3]
Derive a more precise and better-founded definition of acoustic requirements for equipment suppliers, reducing time and cost. Equivalent models to describe source sound power and directivity and the corresponding measurement techniques are developed, based on existing standards (e.g. ISO 3744) as far as possible. The validation of the methods on railway acoustic sources have been assessed as part of the measurement campaign.. [WP1]
Improve source quantification for noise mapping and a more accurate assessment of noise abatement measures. Methods for pass-by source separation and track-vehicle separation have been developed and evaluated during the measurement campaigns with FINE-2. The experimental validation, therefore, includes tests on metro train (October 2021), regional train (March 2022), high-speed train (Sept 2022). Estimates for rolling noise, equipment noise, traction noise and aerodynamic noise contributions have been successfully derived and pass-by source separation methods have been validated. [WP2&WP3]
Enable lighter vehicles, thus lower energy consumption, while maintaining high levels of interior acoustic comfort. Two material design concepts have been selected by FINE-2 and optimized by TRANSIT. One of the concepts (a sound reduction device) performs very promising in simulation. Small-scale lab experiments have been performed in an impedance tube and in a duct section, the performance of the sound reduction device does not meet the expected performance based on the simulations. [WP4]
The developed methods, experiments and results have been presented and discussed at the TRANSIT final conference and others.
