Learning Forum

[aryamnsaini]

I am doing a problem in which the motion of a solid cylinder with spherical end has to be analysed. the cylinder is moving with supersonic speed and the clearance with pipe wall is very low.

what can be the approach to solve this kind of problem?

help, please! 

 

[DrAmine]

Overset + prescribed CG motion might be a solution.

[salmanouh4269197moa]

Hello,

I'm also simulating  a rotating drum filled with spherical particles and I'm confused about how to simulate the motion of the drum with the particles inside 

is it correct to enable the Moving Wall under the boundary condition or go for the dynamic mesh ?

am using Eulerian Granular multiphase model - transient flow  for 2D domain.

Please advice,

[Rob]

If it's just rotating moving reference frame or sliding mesh will do it: dynamic/overset mesh is only really needed if the relative positions of bits of geometry or shapes change. 

[DrAmine]

To be safe always use mesh motion and rotate the whole drum.

[salmanouh4269197moa]

Thanks, I have tried the single moving reference frame and it's seems it will work but the conversion is not complete due to floating point l do not know why?
Would You help!

[DrAmine]

Paste here all relevant details of your case

[salmanouh4269197moa]

Yes, Its Here

[Rob]

Try dropping the Courant Number to about 10-20 (200 is only viable for airfoil type models)  but it's likely you'll need the transient solver: multiphase models are nearly always transient. 

[DrAmine]

I guess you only want to run particle simulations right? If YES: I have done that last week: switch off all flow equations and run just DEM particle with a suitable particle time step size/flow time step size which is 1/20 of particle collision.

[salmanouh4269197moa]

 

Yes I'm doing Particles simulation and it should be in 3D

Do you mean Discrete Element Model? If yes. How I can I applied using Fluent?

 

Regards 

 

[salmanouh4269197moa]

So for the Courant Number, I need to key-in the value not Fluent will calculated based on the 

element size ,inlet velocity and  the time step?

would you explain am confusing about this Courant Number

Regards, 

[manav2107]

I am working on the similar problem. In which a robotic tool is to move (with some velocity) inside a pipe due to differential pressure (upto 150 bar) generated. The pressure must not bye-pass the tool, otherwise it wouldn't move. Also, it should vary its size with the variation of pipe, I am stuck with this problem. What should I do? 

[Rob]

If there's no flow leakage then the motion is purely pressure & friction based. You might be better using Mechanical for the contact models. 

[manav2107]

but the problem is that it has to move always in compression inside the pipeline like a pigging tool. will it be possible in Mechanical?