Analysis and optimization of the chamfered pyramid and evaluation of geometrical parameters' effect on its sound absorption coefficient.

This article focuses on the design and optimization of a chamfered pyramid-shaped sound absorber intended to improve performance in anechoic chambers compared to traditional wedge absorbers. Using finite element simulations in COMSOL Multiphysics coupled with a genetic algorithm programmed in MATLAB, the study optimized the pyramid geometry to achieve a 100 Hz cut-off frequency with reduced thickness, material consumption, and installation complexity. Results indicate that the optimized chamfered pyramid outperforms both full pyramids and wedges by achieving the target cut-off frequency with approximately 16% less thickness, easier arrangement due to its symmetrical shape, and lower manufacturing costs. The study also examines the effects of parameters such as air gaps behind absorbers, base thickness, and spacing between absorbers, finding that small gaps (up to 15 mm) can further reduce the cut-off frequency without compromising absorption at higher frequencies. Overall, the chamfered pyramid absorber offers practical advantages for anechoic chamber construction, including space efficiency, cost-effectiveness, and maintenance ease, while maintaining high sound absorption performance.