On Fri, Nov 15, 2013 at 3:21 PM, Matthew Knepley <[email protected]> wrote:
> On Fri, Nov 15, 2013 at 5:09 PM, Geoffrey Irving <[email protected]> wrote:
>>
>> Is the second equation the weak form of incompressibility? If so, why
>> isn't q u? It's used as q several places throughout the code, so it
>> seems more likely to be my misunderstanding than a typo.
>>
>> < \nabla v, \nabla u + {\nabla u}^T > - < \nabla\cdot v, p > + < v, f > = 0
>> < q, \nabla\cdot v > = >> 0
>
> u, v \in V and p, q \in P, and hopefully \div V = P for stability.
Are you using the same variables as
http://fenicsproject.org/documentation/dolfin/dev/python/demo/pde/stokes-iterative/python/documentation.html
If so, maybe that line should be
< q, \nabla\cdot u >
I.e., "u" instead of "v"?
Geoffrey
