Sound transmission through a double-panel construction lined with poroelastic material in the presence of mean flow

Sound transmission through double cylindrical shells lined with porous material under turbulent boundary layer excitation

“…3 and 5, it can be seen that the air gap is important for reducing of sound transmission in the frequency range between the ring frequency and acoustic coincidence frequency. This phenomenon is also observed when a plane wave transmits through sandwich structures [4,11,12].…”

On sound transmission through double-walled cylindrical shells lined with poroelastic material: Comparison with Zhou׳s results and further effect of external mean flow

“…Hence in Eq. (9) the second term on the right-hand side does not contribute to the transmitted sound power and can be ignored, whereas the first term contains a component normal to the cylinder surface which can be written as I n ¼ ðp 2 0 =ρ i c i Þð1 þM sin αÞ cos α: (10) Substituting the above expression into Eq. (7), the incident sound power per unit length of the shell becomes…”

“…In the analytical modelling of this problem, cylindrical shell structures need to be considered to account for aircraft fuselage geometry (e.g. [1][2][3][4][5]); the effects of external flow must be taken into account for flight conditions [1,[6][7][8][9][10][11][12]. Moreover, sound absorptive materials can be included within the sandwich core to enhance the sound insulation performance of such structures [1,[10][11][12][13][14][15].…”

Homogenization of the vibro–acoustic transmission on perforated plates

“…The proposed modelling conception based on the problem decomposition and using the homogenization provides an alternative framework for modelling of microporous panels which are known for their capabilities of acoustic attenuation [22,23,9]. In [12] the so-called patch transfer functions were developed for numerical modelling of compliant micro-perforated panels.…”