(Color online) Geometry of the silencer benchmark.
(Color online) Numerical results (fe) computed with the LQ scheme and analytical solutions (ana) for the real part of the pressure, the axial, and the radial displacement (quantities are scaled for the sake of clarity). The displacement “Disp.” (resp., the pressure “Pres.”) signifies the fluid displacement perturbation in the airway w (resp., pressure p) for , and the solid phase displacement u for (resp., pore pressure pp ). Computed with , , and f = 600 Hz.
Convergence curves for the pressure. The discretization scheme is given by the line style: —, LL scheme; , LQ scheme; and – –, QQ scheme. The line thickness indicates the domain under consideration: bold line for the poroelastic domain and thin line for the fluid domain. (a) No flow case with . (b) flow with .
Test case mesh.
Effects of the mounting conditions, —, sliding; —, clamped, for two foams: (a) XFM, (b) FM4.
Effects of the shear layer with a mean Mach number ; – –, no flow; —, ; —, uniform, for XFM foam. (a) Downstream propagation. (b) Upstream propagation.
(Color online) Acoustic intensity field at the entrance of the liner at 1 021 Hz, —, uniform flow; —, shear flow. (a) Downstream case. (b) Upstream case.
Effects of the perforated plate properties on the TL (sliding condition for the foam). —, plate 2; —, plate 1; – –, no plate.
Three discretization schemes.
Error for , f = 600 Hz, computed with the LQ scheme. Displacement “Disp.” (resp., “Pressure”) signifies the fluid displacement perturbation in the airway w (resp., the pressure p), and the solid phase displacement u in the poroelastic material (resp., the pore pressure pp ).
Materials properties used in numerical tests Refs. 16 and 33. With the flow resistivity , the tortuosity , the viscous and thermal characteristic lengths and , the Poisson coefficient and the effective skeleton density . The effective skeleton density , where is the density of the material of the frame.
Perforated screen characteristics.
Article metrics loading...
Full text loading...