[vahidet]

I am going to simulate two-dimensional oscillatory flow over an array of cylinders. In order to reduce the mesh size, I am going to model only one cylinder and impose cyclic boundary conditions at all four boundaries (the model consists of a cylinder at the center of a square domain). As a result, I can't impose cyclic pressure condition at the boundaries (which is one of the methods of producing oscillatory flow).

Therefore, I think the only way to do this simulation is to impose a time-varying body force which accelerates the fluid and produces the required oscillation.

I noticed that since version 2.2.0, OpenFOAM has introduced a new framework named fvOptions that provides the possibility of including "sources or constraints on the governing equations, e.g. porous media, MRF and body forces." Unfortunately, I couldn't find any help that guide me through using and implementing fvOption.

Does any one has any idea on how to run this oscillatory flow model using fvOption? and, is it possible at all to impose a "time-dependent" body force using fvOptions?

[Thaw Tar]

Same here. Seeking for answers

[pbachant]

These is an oscillating fixed value boundary condition that you could use: https://openfoamwiki.net/index.php/M...tingFixedValue

[Thaw Tar]

Thanks. However, for me, my problem is opposite to Vahid's. I want to oscillate my cylinders. Not the flow. Sorry for my misleading words.

Thus, I want to create a body force model that can represent an array of multiple moving cylinders in uniform flow.

[pbachant]

Ah, I see now. There is an actuatorLineSource fvOption in the turbinesFoam library (full disclosure: I wrote it and it still needs work). There is an option for harmonic pitching, but you could add harmonic plunging, heaving, or surging. Input to the actuator line is lift and drag versus angle of attack, which is easy to define for a cylinder at fixed Reynolds number.

[Thaw Tar]

Thank you very much! I will look at it