You’re offline. This is a read only version of the page.
Please wait...
×
Error
X
Toggle navigation
Download Center
Download Center
MIKE 2024 Update 1
Scientific Publications
Knowledge Base
MIKE Forums
Contact Support
Contact Sales
Contact Sales
Service and Maintenance Agreements
All
All
Forums
Knowledge Articles
Search Filter
All
Forums
Knowledge Articles
Search all support and community content
Sign in
DHI Group
MIKE Powered by DHI
DHI Training Portal
Metocean Data Portal
Bathymetrics Data Portal
MIKE Cloud Admin
Home
MIKE Forums
FEFLOW
Instability with transient modelling of discrete feature elements
Instability with transient modelling of discrete feature elements
Posted
Thu, 16 Sep 2010 23:16:01 GMT
by
Martin Stewart
Does anyone have experience/success using discrete feature elements in transient models? I am using an existing model which is stable in transient mode with complex arrays of multilevel wells and varying boundary conditions. I am trying to add into the model vertical open boreholes which have been drilled to drain an upper perched aquifer through to a lower partially saturated one.
I have tried using discrete feature elements as single nodes connected vertically across several layers. I am using Darcy's law with a high conductivity (1 m/s) and a 1m2 cross section (they are BIG boreholes). My nodal spacing is a minimum of 1m and is tightly discretized around the discrete elements and I'm using extremely small timesteps to start, but the model is unstable. Any suggestions why it might be unstable? is there an alternate way I can model drainholes that will provide a stable transient solution?
(The instability is particularly apparent at the free and moveable upper surface which is also a seepage face boundary condition)
Thanks
Martin
Posted
Fri, 26 Aug 2011 21:51:09 GMT
by
Jose Pedro Rebes Lima
Hi Martin,
Descrete element makes the model unstable in general, I would recommend you to make high K zone using small FEFLOW elements directly.
Cheers,
Robin
Posted
Tue, 13 Sep 2011 04:13:02 GMT
by
psinton@aquageo.us
try removing the free and movable option...run confined to simplify the problem. its likely that your model set up is ill posed.
Pete
You must be signed in to post in this forum.