Sound Transmission Comparisons of Active Elastic Wave Metamaterial Immersed in External Mean Flow

Abstract

Using the active feedback control system on the elastic wave metamaterial, this research concentrates on the sound transmission with the dynamic effective model. The metamaterial is subjected to an incident pressure and immersed in the external mean flow. The elastic wave metamaterial consists of double plates and the upper and lower four-link mechanisms are attached inside. The vertical resonator is attached by the active feedback control system and connected with two four-link mechanisms. Based on the dynamic equivalent method, the metamaterial is equivalent as a single-layer plate by the dynamic effective parameter. With the coupling between the fluid and structure, the expression of the sound transmission loss (STL) is derived. This research shows the influence of effective mass density on sound transmission properties, and the STL in both modes can be tuned by the acceleration and displacement feedback constants. In addition, the dynamic response and the STL are also changed obviously by different values of structural damping, incident angle (i.e., the elevation and azimuth angles) and Mach number of the external fluid with the mean flow property. The results for sound transmission by two methods are compared, i.e., the virtual work principle for double plates and the dynamic equivalent method corresponding to a single one. This paper is expected to be helpful for understanding the sound transmission properties of both pure single- and double-plate models.

Investigation of sound transmission through a finite length cylindrical shell in the presence of an exterior turbulent boundary layer

“…Maxit and Guasch (2020, 2017) proposed the numerical and semi-analytical methods to model the vibro-acoustic behavior of submerged cylindrical shells periodically stiffened by axisymmetric frames and excited by a homogeneous fully developed TBL. He and Wang (2021a; 2021b) investigated the sound transmission tuned by active feedback control attached to elastic wave metamaterials immersed in water. Also, they (He and Wang 2021a; 2021b) analyzed a sound transmission comparisons of active elastic wave metamaterial immersed.…”

“…He and Wang (2021a; 2021b) investigated the sound transmission tuned by active feedback control attached to elastic wave metamaterials immersed in water. Also, they (He and Wang 2021a; 2021b) analyzed a sound transmission comparisons of active elastic wave metamaterial immersed. Sound transmission of active elastic wave metamaterial with double locally resonant substructures surrounded by external mean flow was proposed by He et al(2023).…”

Enhancing the sound transmission loss in double-leaf partitions with lateral local resonators substructure

“…The attenuation of longitudinal wave propagation by the periodic organization of the LLR substructure was demonstrated by Huang and Sun. 26,27 Recently, He et al 28 used a similar model in an operational feedback control system. According to the dynamic equivalent method, the metamaterial is equivalent to a single layer plate, when the dynamic effective parameter is used.…”