Posted Tue, 10 Jun 2008 09:48:26 GMT by faby
hi,
we are using Feflow to simulate radioactive contaminant transport with decay chain using the multispecies facility of Feflow version 5.2

In this the rate  has to be multiplied with porosity and retardation factor ( pg 208 white papers vol1)      or

rate had to multiplied by porosity (given in help file of Feflow)

if can someone clarify this??

thankx
faby
Posted Tue, 15 Jul 2008 13:48:06 GMT by Alexander Renz
Hi Faby,

I looked up the FEFLOW 5.2 help, but could not find the discrepancy you described, yet. Could you please specify (Equation-Numers in WP, File and Equ. Numbers in FEFLOW Help Files) ?
Thanks a lot,
Alex.
Posted Mon, 05 Sep 2011 12:14:35 GMT by Manish Chopra Bhabha Atomic Research Centre
Dear Alex

i wanna know, while simulating multispecies, in equation editor option there are three factors k, rate and C. Rate we are already putting in rate option. What should be k equal to? is it density multiplied by Kd?

Regards,
Manish
Posted Mon, 05 Sep 2011 12:16:23 GMT by Manish Chopra Bhabha Atomic Research Centre
I am using Feflow 5.2. Another query i am having is that when we do multispecies, parent remains the same. There is no change made to parent so whether single species or multispecies, for parent, results should be same for same properties?
Posted Mon, 05 Sep 2011 12:18:19 GMT by Manish Chopra Bhabha Atomic Research Centre
One more question ...while doing single species how Feflow uses Kd and rate? Can u give me the decay equation?
Posted Mon, 05 Sep 2011 12:38:06 GMT by Manish Chopra Bhabha Atomic Research Centre
Can i get some document explaining each and every option of feflow 5.2? Means if we are choosing some option like if i put Kd or rate etc where Feflow is actually using these inputs and how it is using it (e.g the related equation)?
Posted Tue, 06 Sep 2011 05:34:58 GMT by Manish Chopra Bhabha Atomic Research Centre
I faced a serious problem in Feflow 5.2. I was running multispecies (four species) without production. so i put 'k' corresponding to production equals to zero. It is equivalent to running four radioactive species independently. The results should be same whether we are running this way or we are running all the four species one by one one after the another. But i got different results for all except the first species. I guess even after putting 'k' corresponding to production equals to zero, some production is being taken automatically for the species except the first one. this i m saying because the results i obtained for species other than first one were similar to what i got if i consider other three species as daughter products of the first species and consider production term for these. Please help what can be the problem. 
Posted Tue, 06 Sep 2011 07:31:22 GMT by Manish Chopra Bhabha Atomic Research Centre
Another problem: I am solving a 3D transient flow and transient transport problem of radionuclides. For single species it is running properly but when i am changing it into multispecies, its not running properly. Time step also starts fluctuating (I am using predictor corrector technique for automatic time step). Another funny thing is that. When i am running parent for single species, concentration values are quite different than when i am running parent along with daughters in multispecies. With same properties how it can happen?

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