Hi, It seems that ur problem is very similar to what i deal with couple of years ago which was the effect of melt solidification on its fluidity, is it ur case?
I think that the stabilization you need (mention) is different from what is implied by SUPG etc., ur instability is not due to convection but is due to appearence of a large source term suddenly during time stepping. At first glance, I connect ur problem to incorrect implementation!, I suggest to check the diagonal entries of cells with small permeability value, If I correctly understand ur problem, they should be strictly diagonally dominance and their related rhs scaled by the inverse of diagonal entry should be small. looking forward to hear from others, maybe they have more ... good luck ... ruholla. On Mon, Jul 14, 2008 at 1:54 PM, Isabel Gil <[EMAIL PROTECTED]> wrote: > Hello everybody!! > > I have a question, perhaps you could help me. > > I have a 2D domain where an area is a porous media and there, obviously, > there is a change in some physical properties: porosity (e) and > permeability (K). In this porous area we have a value of porosity less > than 1.0 and a value of permeability with an order of 10e-11. This makes > that incompressible Navier-Stokes equations have an extra-term in this > porous area, called Darcy-term that is (v/K)*u, where v=dynamic > viscosity, K=permeability and u=velocity vector. > > I use FEM (finite element method). I want to use a stabilized FE method. > And as I have a change in physical properties (between flow in free > media and flow in porous media), I don't know what type of stabilization > I should use. I have tested GLS (Galerkin least squares), SUPG ... but > they don't seem to work properly with a big change in permeability value > (in free media permeability values infinity whereas in porous media it > values about 10e-11). > > I would be really grateful if you could give some advice or references > of some articles where the implementation of such stabilized method was > explained. > > Thanks in advance > Best regards > Isa > > > _______________________________________________ >
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