How to obtain a smooth restart for small mesh changes but identical mesh topology?
There are 2 ways for performing a restart on a case with a modified mesh:
1. The standard approach is to use the interpolator
a. If the meshes have a different mesh topology, then this is the only alternative. The restart will not be smooth, e.g. residuals show a jump, as the solution fields have to be interpolated on the new mesh.
b. If the mesh topology is identical for mesh1 and mesh2, i.e. only changes in vertex co-ordinates, then the solution fields can just be copied onto the new mesh file. This is done by the interpolator when setting the following environment variable.
CFX_INTERP_NOCRDVX_CHECK = 1
The restart will be smoother then cor case a) but will still show some jumps in residuals, as boundary IP flows like wall shear and wall heat flux as well as hybrid values are not interpolated onto the new mesh.
2. If the mesh topology is identical, the def-file of the new mesh can just be appended to the result-file of mesh1 by the following command:
cat mesh1.res mesh2.def > mesh2_restart.def
cfx5solve `def mesh2_restart.def
The order of the files in the cat-command is important. The restart by this method will be smooth, depending on the changes in the mesh co-ordinates.