Laura Roll Hydrogeologist

Hi Peter,
Thanks, yes that possibility makes sense.  However I am doing forward tracking starting in the top slice with groundwater recharge, and one node will plot for hundreds of meters in the first slice, but the adjacent node does not plot at all.  It seems to me the vertical gradients should not be different enough to drive one particle down to slice 2 immediately, whereas the other particle remains in the top slice, particlularly if K, recharge, and BCs are not very different in the immediate area.

Another question - As I understand it, If I chose a timestep to view in the postprocessor, then run (say in this case, forward) particle tracking, the particle tracks start at the timestep I am currently in, and run until the end of the simulation ( in my case, the model starts at 0 days, I start the particles at 10 days and they run until the end of the model at 30 days).  I only want to view the particle trace from 10 to 20 days, however.  So I go to the properties of the pathlines and have the option to change the minimum and maximum time to plot (via the color bar).  The minimum is always the start time of the model and the maximum is always the end of the simulation.  When I turn off the "autorange" and change the minimum to 10 and the maximum to 20, no particles plot.  When I change the minimum to 0 and the max to 20, the particles plot again.  This doesn't make much sense to me!  Does this mean that no matter what timestep I am currently in, the model is always plotting particles from time step 0 to time step 30? 

Thanks for you help, I need to understand this so that my pathlines make sense!

Hello,
Does anyone have experience plotting transient pathlines originating from a polyline? When I try to do this, only one or two pathlines plot along one end of the polyline, rather than spreading out over the length of the line, and the number of lines do not correspond to the number of starting seeds.  It doesn't seem to make a difference if I choose the flux-weighted distribution option or not, and although my darcy flux is low, it is not zero.  Has anyone seen this before, and could you tell my why in theory this could happen?

Thanks!

Hi Peter,

Thank you for your reply.  In my case, I can right click and invoke the contextual menu when in the classic interface, but when I try to follow the same process in the standard interface nothing happens when I right click anywhere in the diagram, and more often then not my computer freezes.  I downloaded and installed the latest patch from the website, so am unsure why I can't seem to utilize the feature in the standard interface!

Laura

Hi Alex,
Thanks! My initial simulation time was not zero.  When I changed that and re-ran the model, the error did go away.  However, a new error now pops up:

Not enough memory for fast processing! Using slower file based method instead.
Slow process option: Insufficient memory to store velocity fields for unsteady pathlines.  Switching to a file-based computation which can be significantly slower.

I wait quite a bit of time, and still no particles are displayed (although the legend displays).  Any thoughts on how to resolve this?

I am running FEFLOW 6 on a 32 bit windows 7 system/Intel Duo Core CPU @3.00 GHz/4 GB of memory.  The *.dac file is binary and around 2.77 GB, model is ~130,000 nodes and 250,000 elements simulated over ~40 years/monthly timesteps.

Many thanks!
Laura

Thank you!

hello,
I am trying to plot transient pathlines in my model, using FEFLOW 6.  I seem to be missing something simple about the setup, but am having trouble resolving my issue through the user's manual and/or program help files. 

I keep getting the following error message in the log:
Pathline: initial time greater or equal final time! 

In addition, the pathlines do not plot.

I have followed the following process to try to plot pathlines:
1) load my full simulation file (*.dac)
2) Edit -> Problem Settings -> Pathline Computation: change velocity field to transient, set a fixed homogenous porosity
3) select a group of nodes in slice 1 and save them as "Stored Node Selections"
4) Make sure the start location nodes are selected
5) double click backward pathlines in the data panel

I then get the initial time greater or equal final time error.  I've tried changing the timestep in the simulator toolbar, as well as changing the range of min and max time of pathlines to be displayed, but without any sucess.  If I change the velocity field to "steady" the streamlines plot fine. 

Has anyone else seen this pathline log error and if so, do you have any suggestions on how to resolve it?
Thanks! Laura

Hi Peter et al.,

Is this still on the 'to-do' list?  I am interested in looking at calibration statistics within my model.  Thanks!

To clarify, this solution only works when using the classic interface, correct?  When I tried to follow these instructions while using the standard interface I could not generate a contextual menu when right clicking on the head diagram.

Thanks in advance for your reply,
Laura