Numerical Analysis on Vibro-acoustic Characterisation of Hybrid Honeycomb Structure with Flow Permeability

Abstract

The application of conventional noise attenuating structures was often limited when the exchange of air was required due to the trade-off between their noise attenuation properties and ventilation efficiency. The large physical footprint of conventional noise attenuating structures with flow permeability had also limited their applications. This paper investigated the use of corrugation structure in lightweight honeycomb sandwich panels with flow permeability to improve noise attenuation while preserving ventilation. The vibro-acoustic property of the honeycomb structure with flow permeability at low to medium frequency range (50-3000 Hz) was investigated through numerical simulation. Two different hybrid panel designs with U-shaped and V-shaped corrugations in the honeycomb core had been proposed and were found to exhibit superior sound transmission loss (STL) compared to the honeycomb panel without significantly affecting the flow performance. It was found that in the frequency range of 50-3000 Hz, the unweighted STL of the U-shaped corrugation honeycomb hybrid panel (UCHP) and V-shaped corrugation honeycomb hybrid panel (VCHP) was 19 dB and 25 dB higher than the honeycomb panel respectively with negligible effect on the flow performance. The proposed hybrid panel showed promising noise attenuation applications which involved fluid flows such as in fan and engine noise reduction.

Prediction of acoustic wave transmission features of the multilayered plate constructions: A review

“…Tee et al. [400] considered the usage of corrugation construction in lightweight HSPs with flow permeability. The goal was to enhance the acoustic characteristics while keeping ventilation at the frequency domain between 50normal to 3000normal |Hz based on the numerical approach.…”

Recent advances in acoustic ventilation barriers

“…Without loss, resonators can also be used for the broadband design, owing to the high-efficient reflection from strong impedance mismatch when lossless resonators are at resonant states. For the purpose of ventilation, usually, resonators have holes on opposite panel faces [72], while the panels can be stacked by layers so that resonators are arranged in cascade [73,[75][76][77][78][79]. A ventilation barrier consisted of an array of resonators was proposed by Kim et al [73].…”