Reduced order modelling using parameterized non-uniform boundary conditions in room acoustic simulations

TL;DR

This paper introduces a reduced basis method for rapid room acoustic simulations with inhomogeneous boundary conditions, enabling efficient evaluation of different surface absorption properties in complex geometries.

Contribution

It extends the reduced basis method to handle parameterized non-uniform boundary conditions in 2D and 3D room acoustics, improving simulation speed for diverse scenarios.

Findings

Achieved over 100x speedup in 3D acoustic simulations.

Maintained accuracy within perceptible differences across frequency bands.

Validated effectiveness across various room geometries and boundary conditions.

Abstract

Quick simulations for iterative evaluations of multi-design variables and boundary conditions are essential to find the optimal acoustic conditions in building design. We propose to use the reduced basis method (RBM) for realistic room acoustic scenarios where the surfaces have inhomogeneous acoustic properties, which enables quick evaluations of changing absorption materials for different surfaces in room acoustic simulations. The RBM has shown its benefit to speed up room acoustic simulations by three orders of magnitude for uniform boundary conditions. This study investigates the RBM with two main focuses, 1) various source positions in diverse geometries, e.g., square, rectangular, L-shaped, and disproportionate room. 2) Inhomogeneous surface absorption in 2D and 3D by parameterizing numerous acoustic parameters of surfaces, e.g., the thickness of a porous material, cavity depth, switching between a frequency independent (e.g., hard surface) and frequency dependent boundary condition. Results of numerical experiments show speedups of more than two orders of magnitude compared to a high fidelity numerical solver in a 3D case where reverberation time varies within one just noticeable difference in all the frequency octave bands.