Characterizing attenuation patterns of acoustic waves in discontinuous waveguides for transportation noise control

This study explores the complex behavior of acoustic wave attenuation in waveguides with discontinuities and wave-bearing boundary surfaces. Using the mode matching method, we provide a detailed analysis of acoustic wave behavior under specific wavelength-based boundary conditions. The technical focus is on modeling and simulating wave propagation through waveguides with discontinuities, leading to observable attenuation patterns. Numerical simulations validate the results, showing significant impacts of discontinuities on wave propagation. This research directly contributes to the design and optimization of acoustic systems such as sensors, ultrasonic devices, and noise control in transportation engineering. Through rigorous calculation of the energy functional for each waveguide region, we ensure compliance with the law of conservation of energy. Considering the symmetry in the waveguide structures, reflection and transmission analysis are performed, and dispersive orthogonal relations are established for flexural boundary conditions. The amplitude behavior of transmitted and reflected fields is also visually portrayed in the study with different dimensional parameters. Band reject filters, noise reduction devices, exhaust gas models, and other complex systems in transportation can be solved computationally effectively by extending this technical foundation to multichannel waveguides.