]> https://gitweb.dealii.org/ - dealii-svn.git/commitdiff
Comment on boundary conditions.
authorbangerth <bangerth@0785d39b-7218-0410-832d-ea1e28bc413d>
Mon, 22 Sep 2008 02:03:55 +0000 (02:03 +0000)
committerbangerth <bangerth@0785d39b-7218-0410-832d-ea1e28bc413d>
Mon, 22 Sep 2008 02:03:55 +0000 (02:03 +0000)
git-svn-id: https://svn.dealii.org/trunk@16891 0785d39b-7218-0410-832d-ea1e28bc413d

deal.II/examples/step-31/doc/intro.dox

index 068e63a36a024391728aa23935001f23501e9279..783a4e5c5cdc08cd8dd582e1bdd4c305d392d466 100644 (file)
@@ -946,9 +946,13 @@ The case we want to solve here is as follows: we solve the Boussinesq
 equations described above with $\kappa=1, \eta=1, \mathrm{Ra}=10$. On the
 boundary, we will require no-normal flux for the velocity
 ($\mathrm{n}\cdot\mathrm{u}=0$) and for the temperature
-($\mathrm{n}\cdot\nabla T=0$). No boundary conditions are required for the
-pressure under these conditions. Initial conditions are only necessary for the
-temperature field, and we choose it to be constant zero.
+($\mathrm{n}\cdot\nabla T=0$). This is one of the cases discussed in the
+introduction of @ref step_22 "step-22" and fixes one component of the velocity
+while allowing flow to be parallel to the boundary. There remain
+<code>dim-1</code> components to be fixed, namely the tangential components of
+the normal stress; for these, we choose homogenous conditions which means that
+we do not have to anything special. Initial conditions are only necessary for
+the temperature field, and we choose it to be constant zero.
 
 The evolution of the problem is then entirely driven by the right hand side
 $\gamma(\mathrm{x},t)$ of the temperature equation, i.e. by heat sources and

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