Here now I face a problem with acoustic problem. In star cd version 3.22 I here that this version can solve the acoustic problem. But I do not how to start the module to implement it. can anyone help?

HI !

I think you can refer the Manual for more information.

The aero acoustic module is easy to turn on in the analysis feature option.

And the default setting of aeroacoustic is recommend not to change in the Manual.

tomosada

Hi Lenson,

STAR has a number of capabilities for Aeroacoustics, so it depends on which one you need.

If it is the Lilley source term (a qualitative, steady-state method for identifying aeroacoustic sources), then this can be activated in pro-STAR (go to "Select Analysis Features" and turn Aeroacoustics on).

STAR also has the capability to output information from a transient analysis for aeroacoustic propagation codes (SYSNOISE or Actran). If you are interested in this you require (obviously SYSNOISE/Actran) and an easy-to-install STAR plugin (contact support for further details).

If you are interested in running transient aeroacoustic calculations and coupling to propagation codes, careful consideration of the CFD analysis is required (e.g. it is standard practice to use more advanced turbulence models such as LES or DES). Therefore, we do recommend that you sit the aeroacoustics training course, which encapsulates much of CD-adpaco's experience of successfully modelling aeroacoustic phenomena.

Enjoy!

Alex (of CD-adapco).

hi Alex: I have learned CFD and CAA for a long time. But I still confuse about the couple of the two method.What data sloving by STARCD using LES of RANS must send to CAA for calculating acoustic? Would you please give me some example about this?

Hi Ricklee,

I'm afraid there's no straight answer to this one. It depends on which acoustic propagation code you are working with, and the type of acoustic sources.

Alex.

Thank you for your answer,Alex I want to use LES and Lighthill analogy for predicting aeroacoustic. What data calculated by starCD would be capature? My model is the fluid flowing a cavity.

Hi Ricklee,

We are currently coupled to three propagation codes, all of which are based on Lighthill's analogy, but they work in different ways and require different output from STAR. One, uses the divergence of Lighthill's stress tensor in a volume. The others separate dipole and quadrupole sources. Dipoles require pressure on solid surfaces and quadrupoles need velocities in volume. All data output is time dependant. The general rule as to whether you need to consider dipoles or quadrupoles is to do with the mach number of your case: dipoles dominate at low Mach numbers.

Alex.