AlphaCell computes the acoustic behavior of systems composed by air-gap, isotropic & orthotropic solids and isotropic porous media. Simple and advanced models are available to describe the behavior of porous materials:
- • Delany-Bazley (1 parameter),
- • Delany-Bazley-Miki (1 parameter),
- • Miki (3 parameters),
- • Hamet (3 parameters),
- • Attenborough (4 parameters),
- • Johnson-Champoux-Allard (5 parameters),
- • Johnson-Champoux-Allard-Lafarge (6 parameters),
- • Johnson-Champoux-Allard-Pride-Lafarge (8 parameters),
- • Pore Size Distribution (PSD),
- • Micro-perforated panel (MPP) with circular, rectangular or slit-like perforations (2 to 3 parameters),
- • Woven and non-woven textiles.
The model by Biot (1956) and some of its derivatives can be applied to all previous acoustic models to include the elastic effects of the porous frame:
- • model for visco-elastic isotropic materials (frequency dependent values of Young's modulus, damping loss factor and Poisson's ratio)
- • model for materials showing limp and rigid body behaviour,
- • model for septum (heavy-layer like) materials,
- • model for impervious screen.
The complete double porosity model by Olny & Boutin (5 parameters including pressure diffusion effects) can also be applied to all previous acoustic models to account for perforation effects. A more general composite model is also available.