Hi,
I am implementing Gauge Uzawa method,
and I find the velocity does not satisfy the boundary conditions, for example: u=0;
The velocity correlation step as follows,
u = \hat{u} - \grad(rho);
where, \hat{u} = 0, on boundary, and
\rho is calculated by poisson equation,
\laplace(\rho)=\div(\hat(u)), with neumann condition.
The relative paper:
http://www.math.umd.edu/~rhn/papers/pdf/gau_uza.pdf
Now, I want to control the boundary condition of u = 0.
One way, I try to control the value of u on boundary, directly.
Similar, questions:
https://fenicsproject.org/qa/12578/simply-assign-value-function-unique-vertex-with-coordinate
https://fenicsproject.org/qa/11551/how-to-attach-value-of-number-to-a-cell-of-the-mesh
The seconde way, if we can make sure \grad(\rho) = 0, on the boundary, then, u = 0, naturally.
Some topics;
https://fenicsproject.org/qa/12184/prescribed-normal-velocity-and-tangential-traction?show=12184#q12184
https://fenicsproject.org/qa/8543/tangential-gradient-boundary-conditions
So, I have to find the boundary points, and then, attach values of them, how about high order elements? and the idea is suitable for this problem?
Best Regard!
