Mesh motion control at run-time, not prescribed
 

Dear Community,

I have started working on the implementation of an automatic controller for a simpe trailing edge flap deflection for a given target lift coefficient. I am working on OpenFOAMv2012.

My intention is to control the rotation of an overset mesh of the flap at run-time by means of a PID controller or similar. Therefore, the mesh motion cannot be prescribed in dynamicMeshDict because it needs to be decided and modified at run time by the controller. As far as I know (and have tested using the twoSimpleRotors tutorial), modifying the file dynamicMeshDict at run time does not produce any changes in mesh motion.

I could not find any discussions that adressed how to approach this problem. The two options I am thinking of are:

Writing an external program (e.g. in Python) that follows these steps:

1. runs the solver (e.g. overDyMPimpleFoam) for a short given number of time steps
2. Reads the lift coefficient and calculates the control signal
3. Rotates the flap mesh (small deflection ensured) via transformPoints -rotate
4. Remerges the mesh, maps the previous state and runs again the solver. Repeat until setpoint is reached

The second approach, which I would very much like to avoid at least in the first stages of the project, would be to write my own dynamicFvMesh Class that controls mesh motion with an integrated controller on the code or that reads the control signal at run time.

I would very much appreciate to have your thoughts on this matter. Somehow I have not managed to find any computational studies or projects that do this kind of control in OpenFOAM.

Best wishes!