Hi! everyone, My centrifugal compressor has 12 blades and my diffuser has 15 vanes. So unless I simulate the complete model, the impeller can never share a periodic bc with the diffuser. What type of interface I need to build? the contact surfaces of the impeller volume and the diffuser volume are not of same size so how can the mass flow rate in a impeller passages be equal to the one in a diffuser pasage?

Jack

Please refere mixing plane model for such cases. It may be helpful for you.