Simulation at the nanoscale (submodeling, etc.)
 

Hello everybody,

I'm facing a challenging problem.

I'm simulating the filling of a mould with plastic.

The particularity is that the mould has a nanometric hollow, and I'm interested in knowing how the fluid fills this nanometric hollow which is a rectangle of 200nmx200 nm and with a depth of 300 nm.

Obviously, meshing all the model with a mesh capable of taking into account this zone is computationaly unaffordable.

Unfortunately, carrying out a refinement of the mesh around the nanometric mark leads to incorrect results (I've found literature stating this and I have tried it).

I'm thinking of carrying out a submodeling of the nanometric zone, the procedure would consist on:

1) Carrying out a simulation of the entire mould with normal mesh.
2) Carrying out a simulation of the area around the nanometric mark using as a boundary conditions the results of the macro simulation.

My question is regarding how could I extract the velocity and the pressure profiles. I've tried adding a line in the macro simulation and doing File/Export but the .csv file says null in the velocity column.

Moreover, in the submodeling would I need transient boundary conditions? Or it would be enough for the submodeling to import the initial boundary condition?

I would appreciate your suggestions in how to start solving this problem :)