http://www.comsol.com/community/forums/ Most recent forum discussions Wed, 22 Jun 2011 11:34:46 +0000 http://www.comsol.com/shared/images/logos/comsol_logo.gif http://www.comsol.com/community/forums/ http://www.comsol.com/community/forums/equation/thread/19930/ It seems there's a missing term on LHS of Eq.3.3 in help page:<br /> Earth Science Module &gt; The Solute Transport Interface &gt; Theory for the Solute Transport Interface<br /> the missing term is div(cu), which appears correctly in the rest of the equations in that page.<br /> Wed, 22 Jun 2011 11:34:46 +0000 .1308742486.19930 http://www.comsol.com/community/forums/equation/thread/6260/ Hi,<br /> I am Sandesh, aged 20, and am working on a 3D diffusion model, transient analysis. When i solve the model, i get messages in my log like: &quot;Warning: ill conditioned preconditioner. Increase factor in error estimate to 2485&quot;<br /> When i make even slight modifications in my diffusion equation for the subdomains, sometimes there is no warning and sometimes there are warnings. Does this mean that there is some problem in my model? Also how should i eliminate the warnings?<br /> I would be very much grateful for some help...<br /> Thank you... Wed, 09 Jun 2010 12:31:20 +0000 .1276086680.6260