CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Siemens

Molecular diffusivity & Thermal conduct. = KINETIC

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

LinkBack Thread Tools Display Modes
Old   February 28, 2008, 19:08
Default Molecular diffusivity & Thermal conduct. = KINETIC
Posts: n/a
I'm running RANS simulations concerning gas burner and I use six transported scalars. The molecular diffusivity of each component in the gas mixture is calculated from the Kinetic theory, by means of the formulation 1-50 of the Star Methodology manual. I would like to know how I can output the diffusivity value of each transport scalar of my simulation? It is possible to point it out in PROSTAR? Do I have to use a user subroutine to perform this operation? If yes, please tell me how.

As well, I'm using the KINETIC option also for the conductivity. I would like to know (as for the molecular diffusivity) how to point out the computed conductivity in PROSTAR.

Thank you,


  Reply With Quote

Old   March 3, 2008, 19:59
Default Re: Molecular diffusivity & Thermal conduct. = KIN
Posts: n/a
Well you can use the subroutine called posdat.f to print out any cell data of your the standard routine you can fine an example of how it works. Refer to nom.f (or I don't remember...but in the ufile directory you'll have only one file with the name "nom.*") for the name convention of the code
  Reply With Quote

Old   March 19, 2008, 19:40
Default Re: Molecular diffusivity & Thermal conduct. = KIN
Posts: n/a
Thank you so much! I have looked at the file, founding the following interesting row:

DIF molecular diffusivity (m2/s) of species IS when input to and output from DIFFUS

Now, the idea is to store the diffusivities of my active scalars (one diffusivity for each of mine 6 scalars, named scalar #1, 3, 4, 5, 6, 8) in six passive scalars. Therefore, before to run STAR, I'll open PROSTAR and I create 6 passive scalar (i.e. scalar #: 20, 21, 22, 23, 24, 25) and then save and quit. In the following you can find a subroutine in which I store the value of each diffusivity for each cell, please, may you check it:

C DIFSCR (I) is the passive scalar number to store the molecular diffusivity of species IS

DIMENSION DIFSCR(6) DATA DIFSCR /20, 21, 22, 23, 24, 25/ DO I = 1, NCELL

T(I,1+DIFSCR(1)) = DIF(1)

T(I,1+DIFSCR(2)) = DIF(3)

T(I,1+DIFSCR(3)) = DIF(4)

T(I,1+DIFSCR(4)) = DIF(5)

T(I,1+DIFSCR(5)) = DIF(6)

T(I,1+DIFSCR(6)) = DIF(8) END DO

Is the above script correct?

In this way will I obtain in passive scalar #20 the molecular diffusivity value of active scalar #1, and so on?

  Reply With Quote


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
Thermal Diffusivity of Enthalpy david_h OpenFOAM Running, Solving & CFD 1 November 6, 2010 08:20
Conduct initialization with a old mesh solution Jianfeng Zou FLUENT 1 September 12, 2007 06:06
UDF of interfacial thermal diffusivity galary FLUENT 1 May 24, 2006 10:10
cbextrude-heat transverse conduct guang ai Siemens 1 December 8, 2004 16:19
thermal diffusivity and specfic heat of NO2 intern CFX 0 May 6, 2002 11:07

All times are GMT -4. The time now is 16:34.