[Matt2341]

Hi All,

I’m trying to implement an “opposition control” style flow configuration. (I believe first introduced by H. Choi, P. Moin, and J. Kim - Active turbulence control for drag reduction in wall-bounded flows)

In a channel flow configuration, you define a wall velocity profile (for the Upper and Lower walls) that is based on the wall-normal velocity coming through a detection plane (time-varying). The attached diagram might help show the setup.

OppControlMoin.PNG

I’m not going to lie, this is very much a stretch of my abilities (or perhaps beyond). I was just wondering if anyone had already implemented such a setup in OpenFoam or had any suggestions on setting up these boundary conditions?

So far I’ve been working with the nearWallFields function object to retrieve measurements and also the timevaryingmappedfixedvalue to map a velocity profile to the wall. My original plan was to use the systemCall function to run a python script to process the data and generate a new mapping of inlet values. My concerns (i.e. some of the things I've discovered) with the above approach are that:
1. OpenFoam doesn’t wait for the python script from the systemCall
2. I’d really like to be able to run in parallel but haven’t figured out how you could do so with the above approach.

After re-evaluating things, I started looking around at some other potential avenues, like the externalCoupled function or custom boundary patches (hoping that’s not required).

Anyway, if anyone had some thoughts on a good approach, I’d really appreciate it! Even if you feel like just ruling out some of my rookie ideas, that would be great also.

Cheers