Analytic Formulation for the Sound Absorption of a Panel Absorber under the Effects of Microperforation, Air Pumping, Linear Vibration and Nonlinear Vibration

Figure 10

(a) The effects of microperforation and linear and nonlinear vibrations (low to high frequency excitation, 𝜔_𝑜=387.25×2𝜋Hz, 𝜔_𝑊=80×2𝜋Hz, 𝜌_𝑤=240kg/m², 𝑡=0.8 mm, 𝑎=𝑏=0.1 m, 𝐷=250 mm, 𝜉=𝜉_𝑊=0.01, 𝜎=0.5%, 𝑑=0.4 mm, and 𝜅=10). (b) The effects of microperforation and linear and nonlinear vibrations (high to low frequency excitation, 𝜔_𝑜=387.25×2𝜋Hz, 𝜔_𝑊=80×2𝜋Hz, 𝜌_𝑤=240kg/m², 𝑡=0.8 mm, 𝑎=𝑏=0.1 m, 𝐷=250 mm, 𝜉=𝜉_𝑊=0.01, 𝜎=0.5%, 𝑑=0.4 mm, and 𝜅=10).

(a)

(b)