OpenFOAM – computational fluid dynamics

[bishopdante]

I've known many acoustic engineers who do studio control rooms Etc. to be rather suspicious of modelling, and there are a number of concert halls which bear testament to the complex and fine grained issues of designing by numbers.

I've long suspected that the Thiele Small spring/pendulum model of modelling speakers is far from the whole story, and I've always wanted to be able to visually animate how the nodes and standing waves behave within the enclosure. I've also felt that being tied to basic models of enclosure is a serious limitation on design, the ideal "acoustic simulator" would be able to model any shape of enclosure based upon a model of how gases behave.

Has anybody messed around with Computational Fluid Dynamics software such as OpenFOAM&#174 - The Open Source Computational Fluid Dynamics (CFD) Toolbox

I've just come across it via some people who design jet engines.

 

[bishopdante]

Just found another useful generic physics based modelling tool, which has a specific acoustics element, and is actually intended for modelling the behaviour of speakers, microphones etc. http://www.comsol.dk/showroom/gallery/2312/

http://www.comsol.dk/showcase/speakers-and-microphones/

http://www.comsol.dk/showroom/gallery/1372/

 

[Conrad Hoffman]

They bought Comsol where I work (nothing to do with acoustics) and it can do just about anything if you buy the right modules. The problem is that the program is expensive and the modules to do anything are expensive, all way beyond the hobbyist or even small company budget. There's a powerful free solver called Elmer, but I don't know if it can handle this type of problem. The real issue is that unless one is a gifted expert it's hard to create a model that has anything to do with reality, and in our case it's hard to verify the model to any great certainty. IMO, these programs are incredible time sinks.