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Problems with SUPG body force term
Dear friends,
I have been getting problems with the SUPG term of the body forces (BF) in a program I'm implementing. I have a SUPG/PSPG finite element incompressible Navier-Stokes program where every time I "turn on" the evaluation of the SUPG term of the body force the program blows up. This problem doesn't happen when I use only the Galerkin term and the result seems to be ok. I know that the SUPG term of the forcing terms introduces more non-linearity in the problem, so, my body forces evaluation is before the predictor-multicorrector loop and are linearized with the time lagged velocity field. So, what could be wrong? My SUPG BF vector is defined by: f_SUPG = int[ tau_SUPG * (u grad w) * f] int = integral operator grad = gradient operator tau_SUPG = stabilization parameter u = velocity vector (lagged in time for linearization purposes) w = weighting function f = force vector being f and w defined by: f = sum(N_a*f_a) and w = sum(N_b*c_b) would reach: f_SUPG = tau_SUPG*{int[u*grad*N_a*N_b]*f}*c_b could anybody give me a hand to solve it? thanks FEM |

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