right so in the Stokes subsystem of my equations, in simplified form I am
trying to solve:
div tau - grad p = rhs1
div v = rhs2
where my tau is 2 epsilon as in step-22
The boundary conditions I now want to implement to solve the 'real' problem is:
on the sides (boundary 0): zero tangential
Hi Wolfgang,
right so in the Stokes subsystem of my equations, in simplified form I am
trying to solve:
div tau - grad p = rhs1
div v = rhs2
where my tau is 2 epsilon as in step-22
The boundary conditions I now want to implement to solve the 'real' problem
is:
on the sides (boundary 0): zero
Jane,
I get that the stress boundary can be put into the weak form, but only
really when you have Neumann conditions.
Correct, but prescribing the stress in an elasticity problem is exactly
a Neumann boundary condition.
And why would I have to use a
compute_nonzero_normal_flux for a
Hi Wolfgang,
Apologies but could you just clarify?
I get that the stress boundary can be put into the weak form, but only
really when you have Neumann conditions. And why would I have to use a
compute_nonzero_normal_flux for a zero one?
I believe it my have been my fault not being clearer.
Jane,
The whole point of not imposing zero for all components in a Dirichlet
sense is that I am testing for a case where I have inhomogeneous normal
component of the normal stress, with the tangential stress being zero on
some boundaries.
This case is easy: the stress is only imposed
Hi Wolfgang, thank you for your reply.
I've had another look at the functions available and i'm stuck on how to
implement these in this case.
The whole point of not imposing zero for all components in a Dirichlet
sense is that I am testing for a case where I have inhomogeneous normal
On 11/27/2017 01:16 PM, Jane Lee wrote:
I'm trying to apply some partial boundary conditions to the step-22
stokes problem. I can't seem to find much further help on this and when
I try and implement it, it solves but solution is clearly unstable/blows
up.
I am trying the basics before i
