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-   -   Eddy-Break-Up in Reacfn.f and Sorent.f (http://www.cfd-online.com/Forums/cd-adapco/52733-eddy-break-up-reacfn-f-sorent-f.html)

Daniel November 27, 2001 05:08

Eddy-Break-Up in Reacfn.f and Sorent.f
 
I have been trying to expand the Eddy-Break-Up mode in prostar with a chemical model. Does anyone know how to call the routine for Eddy-Break-Up from within REACFN or SORENT? After trying to encode EBU myself the results obtained were different from the ones obtained using prostar.

Thanks, Daniel

Ossi November 27, 2001 12:44

Re: Eddy-Break-Up in Reacfn.f and Sorent.f
 
Hi,

I do not know how to call the Star routine. But, there are many types of Eddy Break-Up combustion models that can be implemented. Are you sure you implemented exactly the same model as the Star-Cd model ? For example, it makes sometimes a big difference if you take into account the product term in the minimum sentence or not.

Daniel November 28, 2001 05:25

Re: Eddy-Break-Up in Reacfn.f and Sorent.f
 
Thanks Ossi, Yes, I realize slight variations in the Eddy Break-Up are crucial, but I tried to follow the description in the methodology volume (with the product term). No variation I tried produced the desired results.

Ossi November 28, 2001 14:10

Re: Eddy-Break-Up in Reacfn.f and Sorent.f
 
What exactly are the differences between the built-in Eddy Break-Up model and your own coding ?

Daniel November 29, 2001 04:57

Re: Eddy-Break-Up in Reacfn.f and Sorent.f
 
I built a small model of 2x20 cells in which CH4 and air entered separately at one end and left at the other, I monitored the two models at the first cell by the air inlet and obtained small differences in temperature (about 1%) and larger differences in pressure (about 10%) there was almost no difference in species concentrations or turbulence parameters. In the full model I am solving the discrepancies are much more pronounced (due to the cumulative error I suppose). This could be a problem with the enthalpy source term in SORENT, but how can I test this?

Thanks, Daniel

Ossi November 30, 2001 13:33

Re: Eddy-Break-Up in Reacfn.f and Sorent.f
 
I am afraid I cannot help you much. Except to say that I have experinced difficulties with the usersubroutines in DEC machines. The runs crashed without any reasonable explanations with the reacfn.f subroutine. But this was with the v3100A, I think.

If you are sure that your programming does not differ from the built-in model, then you should contact the CD support in my opinion.


Daniel December 2, 2001 05:21

Re: Eddy-Break-Up in Reacfn.f and Sorent.f
 
Thanks Ossi, I have contacted the support, am awaiting thier reply

Daniel


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