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January 14, 2010, 12:14 |
LSFEM for incompressible flow
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#1 |
New Member
Sébastien
Join Date: Jan 2010
Posts: 2
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Hi all,
I try to write a least square finite element code to solve the incompressible navier stokes equations. The equations in u,w,p formulation are a system of 8 first order ODE, they can be writed as A1 * du/dx + A2 * du/dy + A3 * du/dz + A * u with u={vx,vy,vz,wx,wy,wz,p} or in short L*u = F. The least square finite element formulation give for the element matrix and the element vector Ke = integral of { transpose (L*Nj) * (L*Ni)} Fe = integral of { transpose (L*Nj) * F } It look simple but It don't works when I put it in practice. That is what I do : For each element For i=1 to number of nodes in the element I compute L*Nj I compute the matrix vector product Fe = L*Nj * F I assemble this local vector to the global vector For j=1 to number of nodes in the element I compute L*Ni I compute the matrix product betxeen the transpose of L*Nj and L*Ni I assemble this local matrix to the global matrix Do you see my mistake ? Maybe do you know a public source code in free access from the web using the LS-FEM strategy ? Best regards, Sébastien |
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January 14, 2010, 17:28 |
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#2 |
New Member
supeng
Join Date: Jan 2010
Posts: 5
Rep Power: 16 |
I think I may help you about this. I do have one code to solve the incompressible N-S equations. Please contact me via Email if interested.
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