CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   FLUENT (https://www.cfd-online.com/Forums/fluent/)
-   -   Profile for dynamic mesh (https://www.cfd-online.com/Forums/fluent/39601-profile-dynamic-mesh.html)

Giuseppe February 12, 2006 07:49

Profile for dynamic mesh
 
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

Javier February 12, 2006 10:04

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

Giuseppe February 12, 2006 12:21

Re: Profile for dynamic mesh
 
No, I want to do rotate a section of a bluff body around its axis! Do you know how? Thanks

Javier February 12, 2006 13:07

Re: Profile for dynamic mesh
 
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

Giuseppe February 12, 2006 13:59

Re: Profile for dynamic mesh
 
Amico Javier,

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

thomas February 12, 2006 14:07

Re: Profile for dynamic mesh
 
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


Giuseppe February 12, 2006 14:33

Re: Profile for dynamic mesh
 
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...

thomas February 12, 2006 23:45

Re: Profile for dynamic mesh
 
mabe using the DEFINE_CG_MOTION, but i dont know if it is working in sliding mesh !


All times are GMT -4. The time now is 08:53.