I want to compute flowfield aroud a train,the speed of train is 200km/hour,iI have completed grid generation, but I don't konw how to set outer boundary condition properly,

who can help me?

thanks a lot.

How about velocity inlet and pressure outlet ?

Christian

Of course velocity inlet is best one for the front of the train. And pressure inlet is very good one for far field.

Sincerely, Jinwook

thanks for yuor help here is an other problem. I use segregaed solver+laminar flow,why the surface of train have large non-zero velocities?

Be sure to turn 'Node Values' off when displaying velocity contours.

1. I think that the flow should be turbulent flow because the geometry and velocity are enough high(high Reynolds number) to ensure turbulent flow.

2. Of course, the surface of train is zero velocity(no slip condition). Velocity inlet and pressure inlet(or pressure outlet if you prefer) are for far field.

Sincerely, Jinwook