A linearized Eulerian sound propagation model for studies of complex meteorological effects

Area of Science:

• Acoustics
• Environmental Science
• Computational Fluid Dynamics

Background:

• Outdoor sound propagation is complex, influenced by topography and atmospheric conditions.
• Existing models often struggle to capture the intricate interactions between terrain and atmospheric flow.
• Accurate sound propagation modeling is crucial for environmental noise assessment and urban planning.

Purpose of the Study:

• To develop and validate a coupled sound and flow model for predicting outdoor sound propagation.
• To investigate the impact of topography and atmospheric conditions on sound fields.
• To provide a tool for more accurate noise assessment in complex environments.

Main Methods:

• Numerical integration of linearized Euler equations for a coupled sound and flow model.
• Incorporation of topography, ground characteristics (rigid, reflective, absorptive), and atmospheric gradients.
• Validation against analytical solutions and experimental scale model data across four scenarios.

Main Results:

• The linearized Eulerian (LE) sound propagation model showed excellent agreement (< or = 1 dB deviation) with analytical solutions for homogeneous conditions.
• Model predictions closely matched measured scale model data for sound propagation with wind and temperature gradients.
• Deviations in finite impedance ground scenarios were attributed to ground impedance representation, with wind effects on screen shading also agreeing well with measurements.

Conclusions:

• The developed coupled sound and flow model accurately predicts outdoor sound propagation under various conditions.
• The model effectively captures the influence of topography and atmospheric gradients on sound fields.
• This validated model offers a robust tool for environmental noise analysis and mitigation strategies.