the model which has two inlet faces ,two outlet faces,and the ervry pair of inlet-outlet faces is defined as periodicity surfaces respectively.how to simulate this model by fluent? does it need UDF,and how ?

Hi, See thr online fluent documentation/tutorial/periodic flow and heat transfer. thomas

Do not need the UDF, but before you mesh grid, you should link the faces that you want to define them periodic.

When the grid has been read into fluent,I need to input something such as mass flow rate ,flow direction and so on in the periodicity conditions panel.But how does fluent deal with these inputs to every pair periodic surfaces?