This study presents the design, development, and acoustic characterisation of a tessellated polyform absorber composed of perforated panels (PPs) made from jute-reinforced rigid composites. A full factorial optimisation involving 72 combinations—spanning 12 geometric variants, six cavity depths, multiple perforation ratios, and orifice diameters—was conducted using impedance tube measurements. Integration of jute fleece within the backing cavity, combined with an L-tromino tessellation, enabled noise absorption (NAC ≥0.9) across 400–6300 Hz in a single modular structure. To explain deviations from the classical Maa model, the transfer matrix was progressively refined: T 1 accounted for orifice irregularities caused by jute-fibre fraying; T 2 incorporated additional damping from jute fleece in the cavity. CFD simulations were conducted to qualitatively examine the influence of tessellated geometry on local airflow patterns and edge-induced vortical structures around the L-tromino elements. The analysis highlights how geometric discontinuities influence local viscous interaction, supporting the proposed topology-driven acoustic design. The resulting tessellated polyform structure demonstrates high acoustic efficiency along with favourable mechanical strength and fire-retardant characteristics of SMC-based natural fibre composites. This integrated approach offers a sustainable, geometry-driven solution suitable for precision acoustic environments such as recording studios and controlled architectural spaces.
Nath et al. (Mon,) studied this question.