The AcoustoDict module can be considered a digital impedance tube, as it allows the simulation of the acoustic properties of porous microstructures.
Based on a digital model or CT scan, a set of parameters describing the acoustic behavior of the material are computed. These parameters can be used as input to the empirical Delany-Bazley model. Using this model, AcoustoDict predicts the frequency-dependent acoustic absorption curve.
The AcoustoDict module is made up of a simulation component and database component.
The simulation component performs a flow simulation and predicts the input parameters for the Delany-Bazley model from the results.
With the database component, absorption curves obtained from these simulations or from direct measurements are stored for later use.
Multiple absorption curves at different degrees of compression can be stored and compared for each material, for example,
for nonwovens that are often compressed to a given thickness as part of acoustic material fabrication process.
The absorption curves for other degrees of compression can then be predicted interactively from the given data.
The database Match function automatically finds the material that most closely matches a desired absorption curve among the materials within the database. The compression of existing materials to new thicknesses is also taken into account automatically.
The database Stack function predicts the acoustic absorption of a sandwich configuration of up to four layers of different materials, including air gaps. The arrangement and thickness of each layer can be changed individually and the absorption curve for the whole stack is updated interactively.
Examples of AcoustoDict applications
- Research of materials for noise reduction for the automotive industry (e.g. car roof lining).
- Research of sound attenuation in architectural materials.
Additional modules needed?
- The GeoDict Base package is needed for basic functionality.
- AcoustoDict requires the FlowDict module, which is needed for the computation of the Delany-Bazley parameters for a given material. The FlowDict license can be omitted if only the material-database component is needed, i.e. if experimental data from flow or impedance tube measurements is to be used.
- AcoustoDict works on 3D (micro-) structure models that can either be a segmented 3D image (microCT-scan, FIB-SEM) imported with ImportGeo-VOL, or a 3D structure model created with one of the GeoDict modules for Digital Material Design, e.g. FiberGeo for nonwovens or FoamGeo for foams.