Hello, I am wondering how to apply time dependent multiple boundary conditions on dolfinx. I used to define “Expressions” for both Dirichlet and Neumann time dependent boundary conditions in dolfin Legacy see MWE below: from dolfin import * import numpy as np mesh = IntervalMesh(2, 0, 1) V = Fun…

[image] BouteillerP: l_bc = fem.dirichletbc(current_l_bc, locate_dofs_topological(V, fdim, l_bc_facets), V) r_bc = fem.dirichletbc(current_r_bc, locate_dofs_topological(V, fdim, r_bc_facets) The input here should be a single constant, not a product of Constant. If you want to use a product of…

Thank you for your quick response! Unfortunately, using fem.Expression seems to trigger an error: File "/home/bouteillerp/Bureau/Time_dependent_Bcs_Dolfinx.py", line 35, in <module> bc_expr =fem.Expression(l_magnitude, loading, V.element.interpolation_points()) File "/usr/lib/petsc/lib/py…

[image] BouteillerP: bc_expr =fem.Expression(l_magnitude, loading, I’ve edited my post above, as I had a typo. It now states [image] dokken: bc_expr = dolfinx.fem.Expression(l_magnitude*loading, points=V.element.interpolation_points())

Is there anything wrong with my Dolfinx version ? When i try to implement your Expression it throws another error: File "/home/bouteillerp/Bureau/Time_dependent_Bcs_Dolfinx.py", line 22, in <module> bc_expr = fem.Expression(l_magnitude * loading, V.element.interpolation_points()) File "/us…

Thank you very much, it however seems that the ppa still contains the 0.5.2 version, is it to get updated soon ?

@dparsons would be the one knowing this.

There is a regression in ufl 2023.1 used by dolfinx 0.6. This regression needs to be resolved before 0.6 can be provided on the PPA.

That regression has been resolved? Ref: Regression in time required for code generation · Issue #552 · FEniCS/ffcx · GitHub

No, the regression breaks old dolfin, not ffcx.

Time dependent Dirichlet and Neumann BCs

General

dokken February 10, 2023, 3:59pm 6

This was fixed in: Error interpolating on sub of vector function - #4 by dokken

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Time dependent Dirichlet and Neumann BCs

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