Whats the difference between Sliding Mesh and Dynamic Mesh?
 

I have been reading the users guide, but I do not understand the difference between the Sliding and Dynamic Mesh, can someone help me? Please

The simple answer is, the cell shape is changed in dynamic mesh but not in sliding mesh. The dynamic mesh is flexible, computational time consuming, and error prone.

Thanks, I am trying to simulate the following geometry, 2 propels inside a pipe, but the problem is the cellzones, so far I understand that to simulate those shapes I need to use REMESHING therefore Dynamic Mesh, is this correct??

Both propels will be rotating

If the distance between propellors is bit larger you might have a chance to use sliding mesh. For now I am afraid you have to use dynamic mesh. The dynamics mesh might work well because the geometry seems to be simple.

Yes the idea is to work with a cell zone that it is not regular and shares some space with the other cell zone, like in this case both cell zones shares a small common area, it is just a simple test to work on a more complicated simulation (twin screw pump), thanks for your answers and please let me know about your opinions too

sliding mesh vs dynamic mesh
 

please tell more about sliding mesh and dynamic mesh
i am very new to cfd want to know more
thanx

The sliding mesh motion can only have a constant rotating velocity.
For the dynamic mesh, a new angular velocity is calculated during each time step based on the viscous and pressure forces acting on the region.

So if you have a problem where the parts are dependent on the fluid flow you should use the dynamic mesh.

If your region is rotating with rigid walls, the mesh should never deform and thus there is no need to remesh during the time steps.

thanx for information
i am having simple cylinder in the flow domain and i want to know the time history of the cylinder motion during the flow ca you help me in doing that

If you enable the dynamic mesh, you have the option to write the motion history.

Dynamic mesh -> Options, Settings -> Write Motion history.

Then you will get a .out file in your working directory with the angular velocity during each time step.

thanx for reply
i will try that option
regards

moving mesh
 

Hey guys , I have a question regarding moving mesh, I never had experience on this topic, actually I'm modeling an air jet nozzle in which a high pressurerized air goes into a T shape pipe channle , dimentions of these pipes are in MM.
as we don't have any heat exchanging through the wall so I just modeled the fluid zone inside the pipes,
my supervisor asked me to model it with moving mesh, and I have no Idea how can i do it