Denim Umeshkumar Anajwala

Hello,

I am runing a model with PEST and I'm getting some error messages concerning problem domains of the model where the hydraulic head is falling beneath bottom. After finishing the run I try to find the problem domains in the mesh but don't know how to rapidly locate a certain element or node. 

Many tks for the hint. I just try it out and write again afterwards.
I downloaded the Patch No. 9 and after installing it and restarting Feflow the export function works.
Tks again for the rapid support. :)

Hello Peter,

I am using 5.207 Version and just tried again because I try to start a PEST calibration and I wanted to use the created polygons. I have them in smh and shp format but no ply.

Peter.

Thanks for your reply.

A few follow-up questions and comments.

1. You say that for a particular element, the "mean" conditions of the nodes on that element are used such that if I have an element with one node possessing a large inflow, then the in transfer coefficient will be used. I do not understand this since I have assigned a value of zero to the in transfer coefficient to all elements in the model. A non-zero out transfer coefficient is used for all elements, on all layers in the neighborhood of the drain. So even if there would arise an in-flow, q_in = -phi_in * (h_R - h) = 0 * (h_R - h) = 0.

2. I've tried using a maximum flux constraint of Qmax = 0. This works much better although I still see flow from the boundary into the model domain at very small (10-4 m3/d) rates. I can live with that. The problem with this approach is that the model runs VERY slow, for example, 63 hours to simulate 5 days. This is unacceptable when I need to simulate at least 60 days. Can you suggest anything to speed this up?

3. Have I defined the drain properly? I have defined h_R = z, h_min = z, both time constant.

If the head in the aquifer, h, is greater than the head assigned to the boundary (h_R), there should be out flow, that is, flow from the model domain into the boundary, the normal drain operation.

For the reverse condition, equation 14-7 of the White Paper says q = 0 when h_R(t) = h_min(t) AND h(t) < h_min(t). This is what I expect a drain to do, that is, become inactive with Q_in = 0 when h < h_R (= h_min).

What happens in the normal case since I have h_R(t) = h_min(t) AND h(t) > h_min(t)? Is the flux calculated by: q = -phi_out * (h_R - h) or does the contraint condition apply such that q = q_min = -phi_out * (h_R - h_min)?

Dwaine

That sounds similar to what happend to me recently.

I used the SMH tools to create a number of polygons then exported these into a polygon file. On one computer, it worked perfectly. On another, I see a DOS window flash by followed by a message box confirming the export. However, no polygon file is created.

I haven't had time to follow through on this to figure it out.

:(
I tried several times to export a supermesh created in Feflow to a shapefile. I get no error message, but nothing happends. The same to ply-file. Only the export to dxf and to poly worked, but I need a shp-file. The import of the DXF into ESRI-GIS also didn't worked. Is there a bug in Feflow concerning this export of smh-files or am I doing somethig wrong? I tried to export a simple smh-rectangle and it dind't work.

I would appreciate any help. Tks. in advance 

I am having difficulty with representing drains/interception trenches in my model.

I am using a third-type boundary condition, h at the drain nodes is set to z, the node elevations, and a minimum constraint h_min set also to z, the node elevations. The maximum constraint is not set (+ INF). Assigning the BC and the contraint is done by joining to a polygon representing the location of the drain. This assignment is made on adjacent slices (slices 9 & 10 of an 11 slice model). I have assigned the OUT transfer coefficient to be very high (for an ideal drain) and the IN tranfer coefficient set to zero. These transfer coefficients are assigned to each element within the polygon on all layers. The elements within the drain polygon are assigned a Kx=Ky=Kz of very high (for an ideal drain) on all slices. The mesh is very refined in the region surrounding the drain.

My problem is, after the model is done and examine the results in the budget analyzer, I see that that during certain times (transient model) I have water moving from the drain into the domain approaching the same rate that water is leaving the domian into the drain. My expectation is that water should never flow into the model domain from the drains. When there is a preoblem with influx, the in-flowing nodes seem to be consistent, that is, the influx always seems to occur in the same locations.

The purpose of the model is to detrmine the sustained flow rate into the drain so this precludes using type-4 well boundary conditions.

What can I do to ensure that the drain never produces water?

hi again,
[color=purple]i had a problem with summing the rain recharge to my model.[/color]
i followed the instructions of previous forum:
see:  http://www.wasy.de/forum/index.php/topic,182.0.html
i.e.: mesh centers recive recharge, IDW interpolation 1 neighbour. 
afterwards, mesh inspector show "0 in/out flow on top" to elements outside the recharge zone. so far, all good.
however, [color=purple]when i run the model i get recharge to elements which found next to a recharge zone (touch other elements whithin the recharge zone)!!!
i'm using "budget analyzer" - "elements" - no snap.[/color]

is it my error? some consideration of the FEFLOW? maybe software errors?

??

Hi!

I'm trying to use the PATHLINE module in 3D OPTIONS

I'm just wondering how to keep the color settings I had in the postprocessor?!?!?

thank you!

sorry!
think I forgot to say thank you for your reply... I've read it a while ago now!
thomas