Abnormal acoustic transmission in a waveguide with perforated screens

Acoustic Transmission Loss of Perforated Plates

A study has been conducted on the acoustic response of perforated plates at normal incidence. The investigation includes a theoretical analysis of the problem, with validation through experimentation. The acoustic response was quantified through the transmission loss and absorption coefficient of the perforate. The theoretical analysis is based on planar wave propagation through a single contra...

Enhanced and reduced transmission of acoustic waves with bubble meta-screens

Experimental Studies of Wave Transmission through Single Perforated Sheets and Upright Perforated Wave Filters

Far-infrared bandpass filters from perforated metal screens.

Precision nickel printing screens are shown to be very useful as far-infrared bandpass filters. For a range of such regularly perforated sheets, transmission peaks of ~ 0.9 have been observed to lie at frequencies between 60 and 140 cm(-1). We found that this value shows little degradation by cascading several screens, but the overall filter Q value may be increased from 2.7 to a value of ~ 6. ...

High frequency acoustic transmission loss of perforated plates at normal incidence.

A study has been conducted on the transmission loss of perforated plates at normal incidence. The investigation includes a theoretical analysis of the problem with validation through experimentation. The experiments comprised microphone measurements of transmission loss for 11 perforated plates with variable thickness, hole size, and porosity. The theoretical model is based on planar wave propa...