How to assign consistently master/slave cyclics with createPatch
 

Hi everyone, I'm working on a simpleFoam case of a FSAE car, I have modeled 3 fans using the fixedJump BC (also tried fanPressure with the fan curves but i get a lot of convergence problems).
I start from a surface stl of the fan, mesh it as a baffle in snappyHexMesh and then with createPatch i transform it into 2 couple patches, then with changeDictionary i set them as cyclics and apply the fixedJump BC.
My problem is really simple, createPatch chooses randomly who's master and who's slave, so in the end I have a 50% chance my fan is set up right (the jump needs to go in the +x direction).

Does anyone have an idea on how to make createPatch call master the patch on the -x side and slave the one opposite to it?

This problem is wasting my time since I have to check if the fan is actually blowing air and if it's not I need to use a changeDictionary just to change its fixedJump to a negative one to reverse the flow.

Thanks in advance