representation of the directional components hydraulic gradient

Hello everybody,

we are dealing with geotecnical erosion problems and would like to identify zones of dangerous hydraulic gradients.

We need the representation of the [b]directional components hydraulic gradient[/b].
Is there any routine similar to the IfmGetResults*VelocityValue which evaluates gradient rather than velocity?

I do not know exactly how those IfmGetResults*VelocityValue routines are coded, but since the velocity corresponds to the hydraulic gradient times conductivity the implementation seems straight forward (division of velocity with conductance matrix at the element level, after that summation over all nodes and division by the number of nodes at the patch?).

Of course one can figure out a name for the "babies":

                                hydgrdx = IfmGetResultsXhydgrdValue(pDoc, i)
                                hydgrdy = IfmGetResultsYhydgrdValue(pDoc, i)
                                hydgrdz = IfmGetResultsZhydgrdValue(pDoc, i)

Has such a routine yet been developed? Any volunteers for this?

Hector Montenegro

Hector,

I once thought of developping such an IFM module. But things are a little bit more complicate. The IFM functions are dealing with interpolated velocities at the nodes. This interpolation will give you a more smooth distribution of velocity. Espacially at interfaces where conductivity has an aprubt change (and talking about critical gradients this could be the interesting parts of the modell) this could introduce some errors.
So what you have to do is a calculation of the gradients from the head distribution in each element. In the general case (3D modell maybe with a moving surface) this could be quiet complicate...

So what we do now, we export the FEFLOW results to tecplot. Tecplot360  offers some data evaluation functions which also include computation of gradients on nodes or elements.

Zebra