CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Main CFD Forum

The effect of acoustics energy dissipation on flui

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   August 28, 2006, 23:03
Default The effect of acoustics energy dissipation on flui
  #1
David
Guest
 
Posts: n/a
Hi all,

Does any one know that if there is a good book or papers on the CFD and acoustics. In particular, I am interested in the effect of acoustic energy dissipation on the fluid flow.

David
  Reply With Quote

Old   August 29, 2006, 05:15
Default Re: The effect of acoustics energy dissipation on
  #2
Donald
Guest
 
Posts: n/a
Aerodynamic acoustics
  Reply With Quote

Old   August 29, 2006, 12:32
Default Re: The effect of acoustics energy dissipation on
  #3
David
Guest
 
Posts: n/a
Thanks,

There is an acoustics source (say a horn) in my simulation problem. I want to include this term.

I will use a turbulence model (something like k-e model) in the simulation. Thus I have to study the energy generation due to acoustic energy and energy dissipation due to viscous force of fluid.

Can you suggest me a good book of that topic. I am thinking that the simulation of noise generated from fluid may be more mature, how is the reserse problem?

Thank you

David
  Reply With Quote

Old   August 29, 2006, 23:19
Default Re: The effect of acoustics energy dissipation on
  #4
Markus Lummer
Guest
 
Posts: n/a
Hi David,

the damping of acoustic waves in fluids is a function of frequency and generally very small for low frequencies. You can get some hints on this topic by looking for the damping of sound waves in the atmosphere.

Regards, Markus
  Reply With Quote

Old   August 30, 2006, 00:40
Default Re: The effect of acoustics energy dissipation on
  #5
sam
Guest
 
Posts: n/a
Dear Sir

Is it necessary for accoustics we use the LES????

best regards SAM
  Reply With Quote

Old   August 30, 2006, 13:34
Default Re: The effect of acoustics energy dissipation on
  #6
Harish
Guest
 
Posts: n/a
The usage of LES for acoustic problems need some thought.It is possible that the small scales can contain a large amount of acoustic energy and the filtering might become an issue.Recent developments have focussed on subgrid scale acoustic models.

-H
  Reply With Quote

Old   August 30, 2006, 13:49
Default Re: The effect of acoustics energy dissipation on
  #7
David
Guest
 
Posts: n/a
Hi,

I think that lighthill's wave equation may be used to describe the damping of sound wave. What is the effect of damping of wave on the turbulence energy generation of the fluid and energy dissipation?

Do you have any suggestion?

Thanks,

David
  Reply With Quote

Old   August 30, 2006, 15:39
Default Re: The effect of acoustics energy dissipation on
  #8
andy
Guest
 
Posts: n/a
There is usually not much energy in acoustic waves at low Mach numbers and so acoustic waves usually have little affect on fluid motion. There are exceptions where a largely coherent fluid instability can interact with an acoustic wave. For example lecture theatres often have resonant slots/holes designed to extract energy from impinging acoustic waves around the resonant frequency of the cavity. The energy from the wave drives the fluid motion in and out of the cavity which creates strong velocity gradients dissipating energy via the action of viscosity. Note that this works because the fluid instability is largely coherent unlike, say, turbulence. The acoustic wave only gives the fluid wave a weak nudge but the nudge is essentially the same each cycle allowing the local fluid motion to build up.
  Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
ATTENTION! Reliability problems in CFX 5.7 Joseph CFX 14 April 20, 2010 15:45
Rought estimation of dissipation energy MC Main CFD Forum 0 December 10, 2006 21:57
Energy dissipation and Drag coefficient Freeman Main CFD Forum 10 January 27, 2006 08:42
turbulent kinetic energy and dissipation panneerselvam.R CFX 1 July 22, 2005 01:55
calculation of (turbulent) dissipation energy ? max Main CFD Forum 3 August 18, 1999 09:42


All times are GMT -4. The time now is 23:56.