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

what's the initial condition of turbulence?

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 13, 2001, 01:03
Default what's the initial condition of turbulence?
  #1
Paul
Guest
 
Posts: n/a
Dear all:

I want to carry out a DNS of the Navier-Stokes equations. What's the commonly used initial condition which will lead to turbulence?

Thanks in advence.

With regards Paul
  Reply With Quote

Old   September 13, 2001, 11:44
Default Re: what's the initial condition of turbulence?
  #2
Jongdae Kim
Guest
 
Posts: n/a
1. What kind of physical problem do you consider to simulate?

2. Depends on your problem, initial condition could be different.

3. But, if you did not decide your problem, please refer 'Fluid Flow Phenomena, A numerical Toolkit' by PAOLO ORLANDI

  Reply With Quote

Old   September 14, 2001, 06:18
Default Re: what's the initial condition of turbulence?
  #3
Paul
Guest
 
Posts: n/a
Thank you for your reply.

The problem is defined as following:

1) 2-D Navier-Stokes equation, incompressible.

2) Rectangular domain, periodic boundary condition.

3) What's the initial condition which will guarantee

a fully developed turbulence?

4) Can the random noise be used as initial condition

to generate turbulence? Are there some analytical

initial conditions?

  Reply With Quote

Old   September 14, 2001, 09:37
Default Re: what's the initial condition of turbulence?
  #4
Jongdae Kim
Guest
 
Posts: n/a
1. Direct Numerical Simulation of "turbulent" flow means three dimensional analysis(usually) in order to consider vortex stretching which is 3-dimensional phenomenon.

2. Depends on your physical problem to simulate, your initial condition and boundary conditions could be decided.

3. In the case that your physical domain has the source of turbulence production(wall, etc), after some calculation from zero velocity flow field, your flow will reach to the turbulent region. Computational domain size should be modified carefully to include fully developed turbulence.

4. If your problem is to solve the monotonically decaying turbulent flow, some special initial condition is necessary. Please refer chapter 8 of Orlandi's book ( pp52, 8.8 Initial conditions). The book also has source codes which could be applied to your code easily.

Jongdae Kim.
  Reply With Quote

Old   September 14, 2001, 10:06
Default Re: what's the initial condition of turbulence?
  #5
Paul
Guest
 
Posts: n/a
Kim, thanks for your kind help.
  Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
SimpleFoam k and epsilon bounded nedved OpenFOAM Running, Solving & CFD 16 March 4, 2017 09:30
Low Mach number Compressible jet flow using LES ankgupta8um OpenFOAM Running, Solving & CFD 7 January 15, 2011 14:38
Error while running rhoPisoFoam.. nileshjrane OpenFOAM Running, Solving & CFD 8 August 26, 2010 13:50
TurbFoam problemlarge Co number sunnysun OpenFOAM Running, Solving & CFD 6 March 10, 2009 09:05
SimpleFoam k and epsilon bounded nedved OpenFOAM Running, Solving & CFD 1 November 25, 2008 21:21


All times are GMT -4. The time now is 04:59.