Cyclic / Mapped BC with oscillating value?
 

Hello all.

I would like to study the mixing of two fluids in an oscillatory reactor, which consists of several chambers connected in series.

What I would like to do is to simulate a single chamber, by placing an initial tracer in it (for example left half of the chamber with alfa=1 and right half of the chamber with alfa = 0) and then oscillate the flow (inlet velocity with a certain frequency and amplitude - > positive and negative values).
Then I would like to have always the tracer alfa value that is entering the chamber (from inlet or outlet depending on the flow direction) equal to the alfa value that is leaving the chamber in the opposite side.


So for a test case I've created a simple 2D mesh as a rectangle with inlet in the bottom outlet in the top and walls at the sides.

I've tried to explore the cyclic and the mappedPatch boundary conditions but with no success until now.

Using the cyclic BC's in the inlet and outlet I don't know how (if it is possible...) to impose the oscillatory flow, just the initial condition.

By using the mappedPatch, how could I set it to be mapped when the flow is entering the domain but not mapped (zeroGradient, for example) when the flow is leaving?

If someone could give me some hints on how to go on with this I would appreciate.
I also have some difficulties in finding information about some specific cases, for example where can I find information about the implementation and options of the mappedPatch boundary condition, appart from tutorial case (pitzDailyMapped for example) where specific options are used?