Design of cellular solids for acoustic noise cancellation: a multiphase lattice Boltzmann approach

Acoustic technology based on Passive Noise Cancellation (PNC) has emerged as an excellent noise reduction strategy for both small and large environments. In general, PNC primarily focuses on designing specialty cellular materials that can effectively attenuate unwanted sounds by virtue of its intrinsic morphology. Here, we develop Lattice Boltzmann (LB) framework to simulate wave propagation in viscoelastic materials and design multi-phase solids with enabling morphologies that can effectively reduce acoustic noise. To establish the effect of cellular solid morphologies on wave propagation, we analyze the acoustic characteristics of transmitted and reflected waves generated from the fluid-structure interactions. Our findings indicate that cellular solids with vertically aligned perforations exhibit excellent characteristics for attenuation of transmitted waves. On the contrary, cellular solids with circular perforations are efficient for attenuating the reflected waves. Consequently, in real-life scenarios, for sound inhibition and noise filtration systems, cellular solids with vertically striped perforations are preferable while for indoor acoustic systems, cellular solids with large circular perforations are efficacious. In essence, we have not only successfully implemented viscoelastic LBM for simulating the sound waves through multi-phase media but also harness its capabilities for tailoring the morphologies of cellular solids targeted towards a variety of PNC systems. We envisage that our LBM framework is a significant step towards simulating wave propagation in multi-phase materials and can be used to design compact low-cost acoustic technologies.