Development on Light and Thin Broadband Sound Absorption Structure Based on Unequal-Cross-Section Microperforated Plate Series Connection.

The sound absorption structure of a microperforated plate has many advantages and has great potential in the field of noise control. In order to solve the problem of broadband sound absorption of microperforated plates, a series acoustic structure of microperforated plates of unequal cross-section was designed based on the traditional microperforated plate series acoustic structure. Compared with the traditional series structure, the sudden change of cross-section increases the sound energy dissipation and greatly improves the sound absorption performance.

3D-printed sound absorber considering ventilation.

To reduce the noise in a ventilated system, three-dimensional (3D)-printed sound absorbers, based on multiple spiral waveguides, are proposed in this letter. A waveguide unit consists of a fixed-length cylindrical straight tube and a certain number of spiral tubes. The geometrical parameters of the spiral waveguides can be flexibly regulated, aided by the 3D digital modeling method to control the phase of the sound wave.

Sound Power Estimation for Beam and Plate Structures Using Polyvinylidene Fluoride Films as Sensors.

The theory for calculation and/or measurement of sound power based on the classical velocity-based radiation mode (V-mode) approach is well established for planar structures. However, the current V-mode theory is limited in scope in that it can only be applied to conventional motion sensors (i.e.