Temperature-Dependent Sound Absorption Characteristics of Multiscale Microlattice Materials with Hierarchical Porosity

With the rapid development of micro- and nanotechnology, the microlattice plates with geometrical regularity can be precisely designed and fabricated. This material has great potential as a novel acoustic metamaterial for sound absorption applications. The previous work has investigated the unified microlattice materials with a single porosity and demonstrated that it has outstanding sound absorption performance. On this basis, this paper further explored the temperature-dependent sound absorption characteristics of the multiscale microlattice materials with hierarchically double porosity through theory, simulation, and experiment. The results show that the multiscale microlattice materials can provide stronger sound absorption in both low- and broadband-frequency ranges compared to the microlattice materials with a single porosity. In addition, the sound absorption mechanism and temperature effect are studied by the numerical contours of sound pressure, particle vibration velocity, temperature field, and thermo-viscous power dissipation density. Finally, the influence of the geometrical arrangement of multiscale microlattice materials is explored, and the optimal configuration for the best sound absorption is found. This work contributes to the design and development of microlattice materials for high-temperature sound absorption purposes.