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Numerical initial conditions ina PDE problem
Posted 11 janv. 2010, 11:09 UTC−5 1 Reply
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Hi all,
I am asking for help concerning the following simulation, to be run in two stages:
Stage A: first, I solve a 2-dim steady state PDE problem, finding a solution f(x,y).
Basically, f is the solution to an eigenvalue problem.
Stage B: I wish to slightly perturb f: f -->f1 = f + df, where df = df(x,y) is a known function.
Then, f1 is used as initial condition for the same PDE problem of stage A, but now
I run the simulation as time-dependent.
My problem is at the level of stage B: f, and hence f1, comes as a numerical solution, and
has no obvious analytical fit. How can I implement such a numerical function as initial condition ?
I am using COMSOL v3.5 (Not 3.5a !)
Thanks
F. Sattin
I am asking for help concerning the following simulation, to be run in two stages:
Stage A: first, I solve a 2-dim steady state PDE problem, finding a solution f(x,y).
Basically, f is the solution to an eigenvalue problem.
Stage B: I wish to slightly perturb f: f -->f1 = f + df, where df = df(x,y) is a known function.
Then, f1 is used as initial condition for the same PDE problem of stage A, but now
I run the simulation as time-dependent.
My problem is at the level of stage B: f, and hence f1, comes as a numerical solution, and
has no obvious analytical fit. How can I implement such a numerical function as initial condition ?
I am using COMSOL v3.5 (Not 3.5a !)
Thanks
F. Sattin
1 Reply Last Post 13 janv. 2010, 23:44 UTC−5
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Posted:
1 decade ago
Hi
I'm not sure I catched everything, but if I do a "conceptual" case of it in structural, once you do a modal analysis you have the eigenmode/shape as output, which allow you to enforce prescripted displacements, or initial stress (that you may want to scale). Canont you use that as starting point for the second run ?
Good luck
Ivar
I'm not sure I catched everything, but if I do a "conceptual" case of it in structural, once you do a modal analysis you have the eigenmode/shape as output, which allow you to enforce prescripted displacements, or initial stress (that you may want to scale). Canont you use that as starting point for the second run ?
Good luck
Ivar