Rotation of rotor on Virtual Blade Model
 

Hi, I am a student. I am working with a tricopter that have 3 rotors through Virtual Blade Model of OpenFOAM. I have a big problem when I setup clockwise rotation for one of 3 rotors - negative RPM. Other rotors that I setup anti-clockwise rotation - positive RPM. When I setup clockwise rotation, it is not convergence. How I can solve this problem? How I should setup for clockwise rotor in fvOptions?

Please help me! Thank you very much.