Fast time domain modeling of surface scattering from reflectors and diffusers.

Area of Science:

• Acoustics
• Computational Physics

Background:

• Existing acoustic prediction models often rely on single-frequency formulations.
• Kirchhoff boundary conditions are commonly exploited in these models.

Purpose of the Study:

• To develop novel time-domain prediction models for auditorium reflectors and room acoustic diffusers.
• To create time-domain equivalents of existing single-frequency formulations.

Main Methods:

• Formulated approximate, wave-based solutions to the Kirchhoff integral equation using surface meshes.
• Developed new time-domain formulations based on Kirchhoff boundary conditions.

Main Results:

• Validated new time-domain formulations against frequency-domain equivalents.
• Tested models on a plane surface, curved reflector, and Schroeder diffuser.
• New models demonstrated performance between finite difference time domain and geometric room models in computation time and accuracy.

Conclusions:

• The developed time-domain models provide a viable alternative for acoustic predictions.
• These models offer a practical balance between computational efficiency and predictive accuracy for acoustic surfaces.