problem in convergence
 

I currently doing the simulation of Single Expansion Ramp Nozzle (SERN),can any one help me how to stimulate both internal and external 3d flow

You are never going to get an answer with a question as general as that. All I can do is refer you to the CFX tutorial examples and if that is not enough go to CFX training.

ya i am getting a message like this in every iteration


+--------------------------------------------------------------------+
| ****** Notice ****** |
| A wall has been placed at portion(s) of an INLET |
| boundary condition (at 1.1% of the faces, 0.8% of the area) |
| to prevent fluid from flowing out of the domain. |
| The boundary condition name is: in. |
| The fluid name is: Fluid 1. |
| If this situation persists, consider switching |
| to an Opening type boundary condition instead. |
+--------------------------------------------------------------------+

Hi murali,

This means that at the inlet or outlet the flow is re-circulating and this creates a wall.
So if you make the inlet longer or narrower, the message should dissappear.

Thanks
Nelly