What kind of finite element spaces are you using? all the best --cjc On 22 April 2016 at 12:51, Fryderyk Wilczynski <scfw@leeds.ac.uk> wrote:
Hi all,
I trying to test 2d incompressible navier-stokes code, using plane poiseuille flow test case .
I am solving steady state system on a square domain. No-slip on top and bottom walls. Velocity inlet on the left where I specify Dirichlet parabolic profile ("x[1]*(1-x[1])", "0.0"). On the right boundary I specify zero constant pressure.
noslip = Constant((0, 0)) inlet = Function(P2).interpolate(Expression(("x[1]*(1-x[1])", "0.0"))) bc0 = DirichletBC(W.sub(0), inlet, 1) bc1 = DirichletBC(W.sub(1), 0, 2) # zero pressure outlet bc2 = DirichletBC(W.sub(0), noslip, 3) bc3 = DirichletBC(W.sub(0), noslip, 4)
I expect the exact to be v = ( y (1 - y), 0) - (unidirectional flow).
However, I think I must have set that outlet condition up incorrectly as I get vertical flow near the outlet. Is this a common issue? or a sign that there's some bug in my formulation?
Thanks,
Fryderyk
-- http://www.imperial.ac.uk/people/colin.cotter www.cambridge.org/9781107663916