Dear Friends,

I am calculating a flow field by separating it into two parts. The two parts are connected by a interior line. The interior crosses the inlet velocity boundary and the outlet pressure boundary. When I start to interate, Fluent calculate a long time and cannot finish one interation. No error message comes out. Who can tell me how to deal with this problem ? Thanks.

With best regards, You

Sounds like that you are doing a 2d flow simulation. In fact, what is the purpose of putting the interior across both inlet and outlet? I think you may like to try one without the interior line. The flow properties along your interior line can always be obtained by the Fluent postprocessing functions, e.g. define the line in your domain and use 'PLOT' to obtain the velocity or pressure along it.

Dear Friend,

Thank you very much for your mail. I am very sorry that I don't write my problem clearily.

The problem is impeller-baffle problem. It is 3-D problem. The geometry is similar to Fig. 16.2.3 in Fluent Manual. The interface is the dash line in the Fig. 16.3.1. MRF method is used here. The flow is rotationally periodic.

If I use periodic boundary condition on the top and bottom boundary, I can calculate the flow field. But if I change the top boundary into velocity inlet boundary and the bottom boundary into outlet pressure boundary, I cannot calculate the flow field. When I interate, the first interation cost a very long time and it cannot be finished. During the calculation, there is no error message coming out.

Then I change one of the top boundaries (two fluid zones) into periodic condition again and the other keeps the inlet velocity boundary. On the same time, I change the corrponding bottom boundary into periodic condition and the other keeps the outlet pressure boundary. The interation is working. Could you tell me what I can do to solve this problem ?

With best regards, You