|
[Sponsors] |
January 22, 2008, 13:17 |
Acoustics using CFD
|
#1 |
Guest
Posts: n/a
|
Hi guys
Can we do far field noise prediction using any of the CFD codes. If yes which code is it and how can we set up the boundary conditions to solve light-hill equations. Thanks in advance for you reply. Usman |
|
January 22, 2008, 16:24 |
Re: Acoustics using CFD
|
#2 |
Guest
Posts: n/a
|
Hi,
Strictly speaking yes, you can do far field acoustics with CFX (or any other CFD code) but in practise the fine meshes and timesteps required make it impractical. Acoustics software like SYSNOISE (and their are plenty of others) do far field acoustics far better. I think CFX has an interface with SYSNOISE, if not you can link it using MPCCI. Your CFX support vendor should be able to help you with this. Glenn Horrocks |
|
January 22, 2008, 16:33 |
Re: Acoustics using CFD
|
#3 |
Guest
Posts: n/a
|
Hi Usman,
CFX can output noise sources to solve the far-field in Sysnoise or other accoustic codes. If it is fan noise you are interested in, there is a Post macro to calculate far-field noise from a steady-state solution. FLUENT also has some built-in noise capability. Note that calculating accurate noise sources is key, which may require accurate resolution of turbulent structures, pressure fluctuations, etc. This implies a very small time step and a fine grid, which ultimately equates to a long run time. -CycLone |
|
January 22, 2008, 17:03 |
Re: Acoustics using CFD
|
#4 |
Guest
Posts: n/a
|
Thank you Glenn.
CycLone how small time step are we talking about. I would need to keep my courant number close to unity. So if i use equation C = v*delta t/delta x, i should get time step that i would need to resolve my pressure fluctuations right! Regards Usman |
|
January 22, 2008, 17:04 |
Re: Acoustics using CFD
|
#5 |
Guest
Posts: n/a
|
Woops sorry about the exclamation mark.
Regards Usman |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
CFD Wiki - We Need More Help! | Jonas Larsson | Main CFD Forum | 0 | September 26, 2005 08:11 |
Where do we go from here? CFD in 2001 | John C. Chien | Main CFD Forum | 36 | January 24, 2001 21:10 |
ASME CFD Symposium, Atlanta, July 2001 | Chris R. Kleijn | Main CFD Forum | 0 | August 21, 2000 04:49 |
Since Last June | John C. Chien | Main CFD Forum | 3 | July 12, 1999 09:38 |
Which is better to develop in-house CFD code or to buy a available CFD package. | Tareq Al-shaalan | Main CFD Forum | 10 | June 12, 1999 23:27 |