Research on Tunable Bandgap Characteristics of the Phononic Crystal Duct with Piezoelectric Thin Plates for the Broad Noise Reduction

•Compact phononic crystal duct with periodic Helmholtz mufflers and thin plate structures is designed to achieve low-frequency and strong noise attenuation.•The transfer matrix theory and the modal theory of the rectangular plate are applied to calculate the acoustic impedance model.•Sound attenuation mechanisms in the phononic crystal duct are revealed.•Acoustic attenuation characteristics with different parameters are researched in detail.•Phononic crystal ducts with axial and circumferential non-uniform arrangements of mufflers have been studied for broadband noise attenuation.