Thanks Pete,

As workaround I manage to generate some input files: one for the
"power functions" and one for the "time variant ID". For the
generation of the file, I have temporary assigned the boundary
conditions as the time-constant and the I exported them as ASCII file
that I modified and imported again to simulate time-variant boundary
conditions.
However, I noticed that importing an external file using the command
"database" is quite tricky. Following the procedure described in this
forum:

http://feflow.info/forum/index.php/topic,446.msg1332.html#msg1332

I used the commands: Assign - database - Import Time-varying IDs -
Head BC/Seepage - Automatic regionalization.But I had to use 'Inverse
Distance Weighting' with only one neighboring point as the
regionalization method for getting the exact numbers I wanted for each
node.


In theory the command "interpolate" the data. To avoid the
interpolation I used "

On Sun, Feb 8, 2009 at 12:43 AM, Pete Sinton <psinton@...> wrote:
> Hi Gio,
>
> I see your point. There's no way around it but you can create the node
> and power lists outside of feflow and edit them into an ascii fem. I've
> done a lot of this; let me know if I can help.
>
> *Pete*
>
>
> Giovanni Firmani wrote:
>>
>> Pete,
>>
>> assigning a pressure condition or a head condition for feflow is
>> exactly the same. Let assume (as in my case) I have to model a
>> seepage, I would use h=z and p=0. If the seepage boundary changes with
>> time I would need a different power function for each node (as there
>> is a different head for each node). But as p=0 is the same for each
>> node it would be easier to use only one power function for all the
>> nodes. This is the reason why I was wondering if it is possible to use
>> a power function for a pressure boundary condition
>>
>> Ciao
>> Gio
>>
>> On Sat, Feb 7, 2009 at 12:34 AM, Pete Sinton <psinton@...
>> <mailto:psinton%40aquageo.us>> wrote:
>> > Odd, but you are right. On my first attempt, it seemed to work, but when
>> > I looked at the node with the inspector, it indicated the boundary
>> > condition was a HEAD node, not pressure.
>> >
>> > It does not really matter though, because the help file indicates
>> > (consistent with physics) that feflow converts the pressure to total
>> > head anyway using equation h = p/(rho*g) + node_elevation. So if you
>> > input a pressure or a head, feflow ultimately operates on head. You can
>> > input a total head for the vadose zone and it will understand that the
>> > fixed head is above the water table if the head you input is smaller
>> > than the elevation of the node. Such nodes should probably only be set
>> > in a variable-saturation model, not confined or phreatic.
>> >
>> > *Pete Sinton*
>> >
>> > www.aquageo.us
>> >
>> >
>> > Giovanni Firmani wrote:
>> >>
>> >> I tried that
>> >>
>> >> When I use options->pressure instead of head I cannot define any
>> >> time-variant function. It seems that is not possible to assign a time
>> >> variant function for the presure :(
>> >>
>> >> Giovanni
>> >>
>> >> On Fri, Feb 6, 2009 at 3:56 AM, Pete Sinton <psinton@...
>> <mailto:psinton%40aquageo.us>
>> >> <mailto:psinton%40aquageo.us>> wrote:
>> >> > yes - it is done the same you would do with head, but select
>> pressure as
>> >> > the variable of choice. under the mesh inspector, set the light
>> >> > blue button to "options", then select "head (1st kind)" button.
>> Select
>> >> > pressure as the variable of choice.
>> >> >
>> >> > *Pete Sinton*
>> >> >
>> >> > www.aquageo.us
>> >> >
>> >> >
>> >> >
>> >> > Giovanni Firmani wrote:
>> >> >>
>> >> >> Is it possible to set up a time-varying function for the pressure
>> >> >> instead of the head when dealing with unsaturated problems?
>> >> >>
>> >> >> Regards
>> >> >>
>> >> >> Giovanni