Hello to all,

Can someone tell me how can I impose a rotation around the C.G. point of a body with a profile, to use it as motion for the dynamic mesh?

Thanks

Amico Giuseppe, Are you trying to simulate the movement of a piston or a valve? Did you get to work the dynamic mesh?

No, I want to do rotate a section of a bluff body around its axis! Do you know how? Thanks

Amico Giuseppe, to move a body you need to give the coordinates that the CG is going to pass by. All this must be done using a UDF. I recommend you to check the way the valves of a piston are moved. Ciao Ragazzo

Amico Javier,

have you an example of UDF which defines the motion of C.G. point?

Hi, For dynamic mesh you need first to "isolate" the zone in gambit, basically you define the zone and put non-comformal faces. If you use MRF instead of the dynamic you dont need the non-comformal face.

Then in Fluent when you define the boundary you can define the rotation of the fluid-zone with MRF or Dynamic mesh. If you use non-comformal mesh you need to declare you interface-grid. Then if the profile of the rotation is not steady but variate with the time, you can write a UDF to define the angular speed.

There is excellent tutorial about this that you should have a look at it. It is pretty simple to catch.

Hope this help

Hello Thomas,

I have to define a sinusoidal rotation which is function of the time. Can I do this using a profile? I have made this for the motion in X and Y directions...

mabe using the DEFINE_CG_MOTION, but i dont know if it is working in sliding mesh !