Modified analytical model for predicting the nonlinear acoustic characteristics of perforated sound-absorption structures at high sound pressures.

This paper presents a modified model for predicting the nonlinear acoustic characteristics of a microperforated plate at high sound pressure levels with increased accuracy of PARK Model. Based on PARK Model, the acoustic impedance of the cavity behind the plate is taken into account in the equivalent circuit to adjust the velocity in the perforations. The modified model was compared with the previous model to verify its accuracy at high sound pressure levels.

Multi-Order Asymmetric Acoustic Metamaterials with Broad Bandgaps at Subwavelength Scales.

Noise manipulation at the subwavelength scale remains a challenging problem. To obtain better broadband sound isolation within the subwavelength range, a class of asymmetric acoustic metamaterials (AAMs) based on rotation is proposed, and this class of AAMs can further improve subwavelength sound isolation performance by introducing multi-orders. The influences of changing the alternate propagation length of the coiled channel and the square cavity in the unit cell on the band frequency distribution and the omnidirectional band structure were investigated.

Heat Transfer Enhancement of Controllable Aspect Ratio Fractal Channel.

Thermal management technology is a major challenge in high-end equipment. The demand for high-efficiency heat sinks has increased. In this study, a controllable aspect ratio (AR) fractal channel (CARFC) heat sink is proposed to enhance thermal performance.

The acoustic performances of a subwavelength hierarchical honeycomb structure: Analytical, numerical, and experimental investigations.

This paper proposes a subwavelength hierarchical honeycomb structure (SHHS) with a compact lateral dimension and double-band perfect absorption in low frequencies. Unlike the conventional micro-perforated panel (MPP)-honeycomb sandwich absorber, this structure has an additional internal honeycomb with a perforated wall. Therefore, there are two resonant cavities in the SHHS to realize multiple absorption peaks.

Finite-Element-Mesh Based Method for Modeling and Optimization of Lattice Structures for Additive Manufacturing.

A parameterization modeling method based on finite element mesh to create complex large-scale lattice structures for AM is presented, and a corresponding approach for size optimization of lattice structures is also developed. In the modeling method, meshing technique is employed to obtain the meshes and nodes of lattice structures for a given geometry. Then, a parametric description of lattice unit cells based on the element type, element nodes and their connecting relationships is developed.