Observation Point

Hi,

I have a simple question. Can I put an Observation point in the same node of a pumping well?
Because I saw that if i put an Observation point in the same node of the pumping well the resul is very bad but if i put the Observation point near the pumping well (for near I mean few nodes away, about 3) the result is very good, like a real acquifer test.

Thanks

Stefano,
the head at the well node highly depends on mesh discretization. The result will only be realistic if the element size corresponds to an 'ideal element size'. FEFLOW can show the latter for multi-layer wells (FEFLOW 6.1). If the mesh is coarser than that, you will obtain a higher head than expected (and realistic), if the mesh is finer you'll get a lower head. So if your mesh does not consider the 'ideal element size' it might be better to use an observation point that is a bit away from the well.
Peter

Thanks Peter,

What about the "Ideal element size". How can i know what is the better size for my model?
I'm using FEFLOW 6.1

Stefano

Peter
I forgot to ask you, is there a maximum rate for a well?

Stefano

Hi Stefano,

There is no limit on the maximum rate for a well, at least not technically. When you put unrealistic high amounts, you're likely to face stability issues in the simulation.

Bastian