LAUSR

Abstract Based on the acoustic-structure coupling and plane wave theory, this paper proposes a method for predicting the acoustic attenuation performance (AAP) of in-line bladder style hydraulic noise suppressor (bladder suppressor) and investigates the influences of main structural parameters of perforated tube on the AAP of bladder suppressor. The acoustic impedance of perforated tube of bladder suppressor is precisely calculated by building its three-dimensional acoustic field model. The results are as follows. The prediction result agrees well with the published experimental result in the frequency range below about 1000 Hz, and the result between about 1000 Hz and 2000 Hz also has reference value. The bladder suppressor has a better AAP, wider transmission loss (TL) bandwidth and higher TL value, when the porosity of the perforated tube is about 15–25% and the extended inlet/outlet length is about 26 mm. The acoustic attenuation characteristics of the bladder suppressor is more and more like that of a Helmholtz resonator along with the decrease of the porosity, but more and more like that of an expansion chamber resonator along with the increase of the porosity. The orifice diameter has little effect on the AAP of bladder suppressor when it is smaller than 5 mm, and what’s more, the larger the porosity is, the smaller the influences of the orifice diameter on the AAP of bladder suppressor are.