Reset "sorbed mass" for all elements each time Kappa is changed

Dear,

I would like to model a relatively classic 2D flow and mass transport problem over a rectangular domain and I need to change the Henri constant Kappa over time.

The problem is that each time Kappa is changed and in addition at the first time step of the simulation, an equilibrium is computed by FEFLOW and then sorbed mass is created resulting in an improper "global" mass balance. Actually, FEFLOW creates sorbed mass by multiplying the dissolved mass by the Kappa coefficient. In order to skirt this behavior I would like to reset created sorbed mass to zero after FEFLOW has created it. This may require retaining previous sorbed value for all elements and reset the new sorbed mass values with those retained values ...

I found inspiration from this post [url=http://forum.mikebydhi.com/index.php/topic,1312.0.html]http://forum.mikebydhi.com/index.php/topic,1312.0.html[/url], but because I am a very new beginner in programming plug-in for FEFLOW I really need basic help to start. Actually, I don't know how to find [i]Ifm[b]Set[/b]ElementalContent[/i] (and not [i]Ifm[b]Get[/b]ElementalContent[/i]) methods to change the sorbed mass.

I have installed Visual C++ 2008 and I chose the following [i]OnTimeStepConstraint[/i] callback (since I know when the change in Kappa occurs).

I have noticed that [i]IfmSORBED_MASS[/i] from [i]IfmContentType[/i] was certainly the parameter I have to deal with through a [i]IfmSetElementalContent[/i] but I didn't find such a method in "document.h".

Can you please give me support for getting started?

Is that better to check whether a change in Kappa has occurred instead of using the [i]OnTimeStepConstraint[/i]?

Best regards,

Olivier

I have made a few tries but I did not manage to solve my problem yet.

I start at the very first step with Kappa=0 in the whole domain (all elements) and I check that the computed Sorbed Mass is zero. Then I set a value of Kappa and immediately after (I deal with the same time step) I compute again the Sorbed Mass and I found a positive value.

What I need, I guess, is a way to bypass the "automatic setting" of Sorbed Mass when [i]IfmSetMatMassSorptionCoeff1/2[/i] is called from my plug-in.

Best regards,

Olivier