Mac

Hello,

to simulate the flow in a crossection with a free groundwater surface I used the "vertical problem projection" with "unsaturated media" as general type of problem. Analysing the height of the free surface I didn´t found usefull information displaying the hydraulic heads: the isolines in the section didn´t trace the border between the saturated and the unsaturated area as I expected. The view for the saturation was more suitable but shows a zigzag-line.

So, what is the best way to show the free groundwater surface in a 2D vertical model? Is it  to define a very fine mesh in the area where the free surface is expected and than show the distribution of the saturation analysing the border of the area with the value "1"?

Thanks for an answer!

I just learned to use 2nd BCs to simulate a well in detail. So I designed a flux-pipe around a single node over two slices to simulate my well screen which ends in the middle of an aquifer. The half flux-rate represents the pumping rate on the outer flux-border. But there are still two open questions:

1) To avoid that the well takes effect as a drinking straw at its lower "open end" by the flux-rate of the inner border, I planned to set an extrem low conductivity to all inner cells of the flux-pipe to plug it. Is that the right way?

2) On which layer does a flux-border on one slice (or the lowest slice in case of multilayer-flux-borders) take effect? For to calculate the correct flux-area and rate, do I have to consider the distance to the nodes ahead or to those above or should I add the half of both distances?

Thank You for an answer!

O.K., now I can interprete all "strange" pathline-sections I observed in my model.

Thank You!

O.K., but why do all pathlines end in my example in one node even when the node above or below has the same pumping rate to simulate a multi level well? Are all well-nodes taking effect although all pathlines are ending in only one (the last part of the pathline seems to be nearly vertical)?
Thank You for an additional answer!

The end of pathlines at multi level wells seems to depend on where the wells defined: Using 4 slices (homogeneus aqufer) and a well on the 2nd and 3rd all pathlines ends between these two slices. Transfering the wells on the 1st and the 2nd slice all pathlines are ending at the node on slice 1. With wells at the nodes of slice 3 and 4 all pathlines are ending at the node on slice 4. With wells at all slices, all pathlines are ending at different levels!

Is this a bug? I estimated the pathlines to end at different levels depending on the defined screen of the well.

Discussing a mysteriuos head at a well-position with the hotline, I´ve been told, that generally it is the "better" way to simulate wells by using 2nd kind BCs instead of 4th. But there is no such comment in the manual! So my question is:

So, should I generally use 2nd kind BCs for "normal" wells to avoid mistaces or are there any special cases in which it is necessary to do so? Or should I, as I´m used to do, simulate wells by 4th BC as I´m told by the manual?

Thanks for an answer!