Improved Modeling of Wheel-Track Rolling Noise for Noise Control near the Source

• Applicant: Professor Dr.-Ing. Ennes Sarradj
• Subject Area: Acoustics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 563291959

Noise in rail transport is predominantly caused by wheel-rail rolling noise, which poses a significant challenge requiring targeted measures for reduction. Mitigating noise at its source is more efficient than using noise barriers. However, this requires a thorough understanding of noise generation, propagation, and the dynamic interactions between railway vehicles and track structures. The established 'beam on elastic foundation' (BOEF) theory provides a foundation for addressing these challenges, but several critical issues remain unresolved. Some current models simplify the problem by neglecting nonlinearities or focusing solely on the vertical dynamics of the rail. As a result, they fail to comprehensively represent the real-world conditions of the track. Additionally, the effects of interactions between multiple wheels on rolling noise are only partially understood, despite their known significance. Furthermore, existing models lack the capability to evaluate practical approaches for modifying track structures to target noise reduction effectively. To address these gaps, an existing finite difference model (FDM) will be enhanced. This will enable the efficient and comprehensive simulation of acoustic interactions between railway wheels and allow for a realistic representation of track properties. The aim is to identify untapped potential for noise reduction and to implement targeted measures to lower noise pollution effectively. The project is divided into four work packages. The first step involves extending the FDM to account for structural noise propagation up to 5 kHz and the radiation of airborne noise. This will include the integration of the Timoshenko beam theory and coupling between bending and torsional waves. Next, the contact dynamics of multiple wheels on a sufficiently long track segment will be modeled, considering nonlinear, time-dependent forces in both vertical and lateral directions. The third work package focuses on validating the model using existing literature data and measurements from train pass-by events. Finally, the validated model will be used to analyze modifications to wheels and track structures and their effects on rolling noise. These enhancements will facilitate the development of innovative approaches to reduce wheel-rail rolling noise. The results have the potential to significantly decrease noise pollution for affected communities and improve public acceptance of rail infrastructure projects.

• DFG Programme: Research Grants