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-   -   Molecular diffusivity & Thermal conduct. = KINETIC (http://www.cfd-online.com/Forums/cd-adapco/56475-molecular-diffusivity-thermal-conduct-kinetic.html)

Kenji February 28, 2008 19:08

Molecular diffusivity & Thermal conduct. = KINETIC
 
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,

Kenji


Andrea March 3, 2008 19:59

Re: Molecular diffusivity & Thermal conduct. = KIN
 
Well you can use the subroutine called posdat.f to print out any cell data of your interest...in the standard routine you can fine an example of how it works. Refer to nom.f (or nom.inc??? 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

Kenji March 19, 2008 19:40

Re: Molecular diffusivity & Thermal conduct. = KIN
 
Thank you so much! I have looked at the nom.inc 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?



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