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### inverse goes into loop (II)

Posted: **Wed Aug 22, 2018 10:17 am**

by **tomgreen**

hi,

when running the inverse solution to determine solute tranpsort parameters the model goes into a loop of unreadable numbers at the end of the simulation. a year ago i had a very similar

problem which was solved- now something else is amiss.

hope you can take a look,

thanks!

tom

### Re: inverse goes into loop (II)

Posted: **Thu Aug 23, 2018 9:57 am**

by **Jirka**

You cannot have Beta (the Freundlich exponent) equal to zero. It should be equal to 1. J.

### Re: inverse goes into loop (II)

Posted: **Thu Aug 23, 2018 1:49 pm**

by **tomgreen**

hi, put beta to 1, but it still goes into that funny loop at the end.

tom

### Re: inverse goes into loop (II)

Posted: **Sun Aug 26, 2018 1:06 pm**

by **tomgreen**

if i put zero for the max number of iterations in the inverse solution window it also goes into this funny loop at the end,

but there are results. if the number of iterations is more than zero there are no results.

tom

### Re: inverse goes into loop (II)

Posted: **Wed Aug 29, 2018 1:24 pm**

by **Jirka**

I have cleaned up your project and had no trouble running it for more than zero inverse iterations. However, your initial guess of dispersivities was pretty good and I have to admit that I do not see much reason for trying to improve the fit further. See the comparison between results for initial parameters (left) and after 2 iterations (right). J.

### Re: inverse goes into loop (II)

Posted: **Wed Aug 29, 2018 3:27 pm**

by **tomgreen**

thanks Jirka!

i made a list of the 'clean-up' you did so that anyone that has the same issue can be helped by it:

time information window:

lowered the minimum time step in the from 1.44e-017 to 1.44e-005

output information window:

turned on T-level info to 25 in the (it was turned off)

set the interval output to 10 min (it was 1)

turned off the screen output (it was on)

iteration criteria:

put the number of iterations down to 10 (from 25)

solute transport window:

put the absolute concentration tolerance down to 0 (from 0.1)

reactions parameters for solute material one window:

put higher values for disp T and disp L (probably to see if they would change from what i had originally put, did not put anything in the minimum or maximum values)

put beta to 1