Tesla valve-inspired metamaterial design for enhanced acoustic performance in load-bearing mortar

Abstract

Low-frequency noise remains a persistent environmental challenge, yet conventional absorbers often struggle to address it without requiring excessive thickness or loss of structural capacity. This study introduces a Tesla-valveinspired acoustic metamaterial, the asymmetric coiled channel, embedded within a high-strength mortar matrix. The asymmetric coiled channel's tortuous and asymmetric geometry enhances low-frequency sound dissipation by increasing viscous and thermal losses while preserving load-bearing performance, thereby resolving a key trade-off in cementitious acoustic systems. By varying the channel coiling angle, we increased the effective acoustic path length and improved low-frequency absorption without altering panel thickness. The DET-90 (a detachable with a 90 degrees coiling angle) configuration achieved the lowest resonance frequency and the strongest low-frequency absorption among the tested configurations, demonstrating enhanced performance across the targeted low-frequency range. To extend performance into mid-to-high frequencies, selected samples incorporated Helmholtz resonators, providing targeted enhancement without compromising structural integrity. Overall, asymmetric coiled channel-based panels increased the surface absorption area ratio from a low baseline value to a substantially higher level compared to the reference specimen, while all specimens maintained high compressive strength, confirming the structural viability of the proposed design.