Multiphysics package gains acoustics addon

Edited by the Engineeringtalk editorial team Nov 13, 2006

Scientists and engineers interested in creating and measuring sound or acoustic waves can benefit from new simulation capabilities for the Comsol product line.

Scientists and engineers interested in creating and measuring sound or acoustic waves can benefit from new simulation capabilities for the Comsol product line - now available in the Acoustics Module.

It is ideal for examining mechanical wave phenomena in structures and fluids.

It is designed specifically for those who work with devices that generate, measure, and use acoustic waves.

Users can easily model wave propagation in solids and stationary fluids as well as study aeroacoustics in moving fields.

Just a few application areas include the audio industry such as for loudspeaker design, whether for stand-alone speakers or those embedded into electronic appliances like cellphones; for underwater object detection and characterisation; and far-field processing to predict radiation patterns and signal strength.

The module provides a variety of application modes, which offer tailored user interfaces loaded with predefined settings important for acoustics applications.

Users create or import a geometry, fine-tune the physics settings, and solve the problem.

A material library facilitates speedy model setup.

One user of Comsol software who is especially pleased to see the convenience he will be gaining through the Acoustics Module is Dr Mario Zampolli, a researcher at the NATO Undersea Research Centre in La Spezia, Italy.

As he explains: "Our studies donandacute;t fall into conventional areas, so until now there have been no specialised tools for our underwater-detection projects".

"With Comsol Multiphysics, though, you can tailor virtually everything to your particular needs, and I find the package very impressive".

Several features make the Acoustics Module particularly adept at addressing this range of applications.

For instance, the theoretical domain of most acoustic problems is infinity, but modelling that domain is beyond the capabilities of any computer.

To allow the successful modelling of a truncated well-defined space, the Acoustics Module uses perfectly matched layers (PMLs), a technique that has emerged as perhaps the most convenient yet accurate way to truncate an open acoustic environment.

A PML is an additional domain that absorbs incident radiation without producing reflections.

To help users get a head start on developing their models and to learn tips and tricks to make their modelling more effective, the module comes with a Model Library that contains more than a dozen entries.

Each comes with a detailed theoretical discussion followed by step-by-step instructions, although users can instead simply load a supplied model file.

One example looks at how to design a woofer and thus involves the multiphysics coupling of electromagnetics, acoustics, and structural aspects.

Another examines the open-pipe problem, which is a classic benchmark dealing with resonances.

A third studies reflection of forward-propagating modes in a jet engine intake, including a compressible flow and PMLs; results are compared with published simulations and semi-analytical solutions.

The Comsol Acoustics Module, selling for US $4995, is an addon module for Comsol Multiphysics ($7995), which provides the overall modelling framework including a CAD editor, facilities for defining physics and boundary conditions, mesh generation, solvers, and postprocessing.