Learning Forum

[S1d996]

Hie everyone,

I'm simulating 3D rotating body with sliding mesh and 6DOF.

while simulation is going on, it is showing a warning like....

Warning: incompatible interaction between moving mesh and dynamic mesh model detected!

Can anyone help me to resolve it?

Thanks in advance

Sid

[Rob]

Images and some idea of what you're doing will help. 

[S1d996]

Thanks for response rwoolhou

I have attached the images below 

• First image is my input 6dof body (Propeller) which should move in +Y direction and circular discs are used as interfaces (sliding Mesh).

1. Hooking 6dof to Blade (which is defined as wall in BC) with 6dof-on, passive-off

2. Hooking 6dof to fluid Zone enclosing the Blade (which has all surfaces defined as interface). The only wall inside the zone is Blade.

    here 6dof-  on, passive-on.

3. When the relative motion is turned on along with point-1, the below mentioned warning is displayed in console area with the updated mesh motion .

      Warning: incompatible interaction between moving mesh and dynamic mesh model detected!

   Warning: dynamic mesh zone 19 (rigid body) with different CG uses 6DOF...
   6DOF rigid body::libudf:: reference CG (6.21188e-01  6.21799e-02 -2.98251e-04)
   6DOF rigid body::libudf:: different CG (6.21188e-01  6.19351e-02 -2.88150e-04)

  Warning: dynamic mesh zone 17 (Rotating zone) with different CG uses 6DOF...
   6DOF Rotating zone::libudf:: reference CG (6.21188e-01  6.15001e-02 -2.72000-04)
   6DOF Rotating zone::libudf:: different CG (6.21188e-01  6.00420e-02 -2.682179e-04)

4. Have a doubt on which type of interface should be used while creating the interface zone between the discs so that the disc interface should        move in accordance with the balde CG. 

•   The Secong Image is the Output of the simulation in which the Disc interface is not associated with the Blade Orientation.

[DrAmine]

Blades and the fluid domain around them have to use the same rigid body udf. The domain does not enclose both in the picture

[S1d996]

Thanks for reply 

Im using same rigid body udf for fluid and blades and i didn't get the point what you have mentioned about " The domain does not enclose both in the picture"

 

[S1d996]

Hie abenhadj

While above mentioned simulation is running, i got new warning as mention in the image

can u help me with this?

 

[DrAmine]

Fluent detected contact and you did not define an UDF for that

[S1d996]

But my simulation 6DOF body has no contact with any solidbody as mentioned in above picture

[Rob]

I think your problem is that the sliding interface is conflicting with the 6DOF motion. Try with a moving reference frame and see if that works. 

 

[S1d996]

Thanks for the suggestions and i request you to give me a solution regarding my first issue 

Warning: incompatible interaction between moving mesh and dynamic mesh model detected!

with regards 

Sid

[S1d996]

I wonder Why the Ansys Support Is to replying to any of the questions posted here.

[S1d996]

Very Disappointing

 

[Rob]

You had the same problem with mrf and 6DOF? 

 

[S1d996]

i did'nt do the MRF model and the error was not seen with the 6DOF

 

[Rob]

mrf and moving mesh?

[DrAmine]

Again the help does state very clear and straight (User's Guide 11.1): Sliding mesh and dynamic mesh are incompatible if they are combined within the same cell zone or adjacent cell zones. If you want to combine these two models within the same case file, they must be separated by a non-moving cell zone.

 

[S1d996]

Thanks for the reply

As mentioned above, i removed the deformation of the outer fluid and the simulation ran smoothly till 0.1 sec 

But, later the discs are moving apart as mentioned in above problem.

So, can u mention me where am i going wrong 

Thanks in Advance

SID

 

[Rob]

Look carefully at what is (and isn't) moving, and how they're related.