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Micro-Macro Acoustic Modeling of Heterogeneous Foams with Nucleation Perturbation
ISSN: 2641-9637, e-ISSN: 2641-9645
Published September 30, 2020 by SAE International in United States
Event: 11th International Styrian Noise, Vibration & Harshness Congress: The European Automotive Noise Conference
Citation: NGUYEN, C., Guilleminot, J., Detrez, F., Langlois, V. et al., "Micro-Macro Acoustic Modeling of Heterogeneous Foams with Nucleation Perturbation," SAE Int. J. Adv. & Curr. Prac. in Mobility 3(2):1068-1074, 2021, https://doi.org/10.4271/2020-01-1526.
The properties of a polyurethane foam are greatly influenced by the addition of graphite particles during the manufacturing process, initially used as a fire retardant. These thin solid particles perturbate the nucleation process by generating bubbles in their immediate vicinity. A large body of work has focused on foams that are reasonably homogeneous. In this work, we propose a modeling approach for inhomogeneous foams that includes membrane effects and allows pore size distributions to be accounted for. The cellular structure of the foam is obtained through a random Laguerre tessellation optimized from experimental properties. The structure of real foam samples is analyzed using X-ray computed tomography and scanning electron microscopy, followed by image processing, to create three-dimensional, digital models of the samples. The corresponding effective material parameters, including the permeability, the tortuosity and the viscous characteristic length, are subsequently computed by applying a numerical homogenization approach. All the numerical data are presented, discussed and gauged against experimental results.