Models

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:


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:

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.

Sound source excitations

AlphaCell can compute the responses of multi-layered structures for a wide range of source excitations:

Details of the top panel with switch buttons for absorption/transmission configuration (bottom left - rigid backing is selected) and source excitation (bottom right - diffuse sound field is selected).

Finite lateral dimensions of materials can be accounted for using spatial windowing techniques also called FTMM (Finite Transfer Matrix Method). Currently, the techniques by T. E. Vigran, Ghinet & Atalla and Rhazi & Atalla are available.

Results

AlphaCell computes surface impedances, reflection coefficients, sound absorptions and transmissions, and impact sound attenuations. In addition, the single number quantities (e.g. alpha_w, R_w, R_living, DeltaL_w...) associated with these indicators are also computed.

For each simulation, results can be saved as a comma separated file which can be later on opened with AlphaCell, Microsoft/Libre Office, Matlab/GNU Octave...
A PDF report can also be generated for each simulation. This report can include a summary of the configuration, the material list, the models used and a graphical representation of the results.

Operating system compatibility

AlphaCell is powered by Java. Thus it runs under all operating systems (32 or 64 bits) supporting this widely used language: Windows, Mac OS X, GNU/Linux, Un*x.