I am loooking for a package or code which can do some computational aeroacoustics calculations for ducts, at one end there is a fan, and the other end is open (frequency domain and time domain). The maximum Mach number inside the duct is about 0.7 with some seprated turbulent regions, so it can't be considered subsonic. The cross0section of the duct is not constant and varies along the longitudinal axis of the duct.

If anybody knows such a software or code, please let me know.

Appreciate it.

Jim

> The maximum Mach number inside the duct is about 0.7 with some
: seprated turbulent regions, so it can't be considered subsonic.

This is not clear. If the maximum Mach number is 0.7...?

What question are you trying to answer and how much computing resource do you have available?

star-cd has an es-acoustics module... i have done several duct flow-noise simulations with it...

I am not an expert on aeroacoutics, so I just want to do this simulation without going through the equations or coding. By M=0.8, I meant that the flow cannot be considered inviscid or potential in this case.

Can FLUENT do flow-acoustics calculation ? And, is there any house-made code which can buy it?

Thank you. Dan

I am more confused now. Are you Jim the original poster? And by M=0.8 (or 0.7) the flow in the duct is subsonic? Is the flow through the fan subsonic?

To the degree I understand your problem, it looks similar to that encountered by the manufacturers of gas turbine engines who employ a range of prediction methods to tackle the various sources of noise and its propagation through ducts and out into the far field. If you want to know what can be achieved by real engineers addressing real engineering problems this is probably the best place to go to find out.

> Can FLUENT do flow-acoustics calculation ?

There are a whole range of acoustics problems and, last time I checked a year or two ago, FLUENT could address a subset of them in a somewhat indirect manner.

> And, is there any house-made code which can buy it?

I do not wholly understand this question. Acoustics problems are generally not tackled by a CFD-type approach. If you want to use a CFD-type approach you will need a lot of time on large parallel computers and access to suitable codes which were not commercially available last time I looked.

However, it is possible to address many acoustics problems without using a CFD-approach or, alternatively, using CFD for the flow and something else for the acoustics. But all this depends on the nature of the acoustic sources (propagation is usually less of a problem) and what engineering problems you are trying to address.