Hi there.
I have a problem with the variational formula in Navier stokes . the term is (u.nabla)u. and the test function is v. when i write the variation formulation ‘’‘inner(((u nabla) u), v)’’’ Fenics dont work.
Is someone have idea
You should not use TrialFunction for non-linear problems, see: https://bitbucket.org/fenics-project/dolfin/src/master/python/demo/documented/nonlinear-poisson/demo_nonlinear-poisson.py.rst