[g-wagon]

dear all of FLUENT user
i think i'm facing a problem now with my dynamic mesh analysis simulation, i dont know why but this error come almost in my simulation. did i do something wrong please need your help, here is some crop picture of my simulation...

[BigBen]

Your moving mesh set up is not well defined.
After a number of iterations, cells get negative volumes=> remeshing due to your moving mesh creates bad cells and Fluent cannot follow the simulation.
Make a preview of the deforming mesh motion if you can or verify where the bad cells are to understand where the moving part of your geometry is creaing bad cells.

[g-wagon]

thanks for the reply bigben, but i'm newbie in moving mesh simulation, would you tell me about how to do that??

[BigBen]

There are 3 differents moving mesh. Which one are you using: Remeshing/deforming/layering?
Give me your email, I may have some pictures showing how to do it.

[abdulrauf.abdulrazak]

Originally Posted by BigBen

There are 3 differents moving mesh. Which one are you using: Remeshing/deforming/layering?
Give me your email, I may have some pictures showing how to do it.

hi.. I am having the same problem like those other guys above there...can u help me how to solve the problem? i was doing a simulation of compression until expansion stroke in combustion chamber of SI engine

[BigBen]

which deplacement do you have? Which kind of cells do you have?
make a picture of you have and what kind of deplacement you want on it to give me an idea

[abdulrauf.abdulrazak]

Originally Posted by BigBen

which deplacement do you have? Which kind of cells do you have?
make a picture of you have and what kind of deplacement you want on it to give me an idea

for my case, u may refer to http://www.cfd-online.com/Forums/flu...amic-mesh.html

please help me..i am doing this analysis for my undergraduate project
thanks

[BigBen]

Reffering to ur picture, ur mesh is purely hexa/quad, only layering can be applied starting at the botom of the "Piston".
Did you mesh the piston thickness? (just for understanding)

If you want to remesh your volume, you need to mesh it in tetra and not in quad.

So what did you do?
When is the error appearing?

[jameil.sk]

Hey Bigben.......here s my email id...jameil.sk@gmail.com
Can u send me some screen shots of how to make the remeshing,layering and smoothening work??

[suguaspire]

Originally Posted by BigBen

There are 3 differents moving mesh. Which one are you using: Remeshing/deforming/layering?
Give me your email, I may have some pictures showing how to do it.

I'm also get same problem can send that pictures for me also. This is my mail id
suguaspire@gmail.com
Thank you

[sanjeetlimbu]

I am facing issue of negative volume
i am using 2D planer mode - for compression stroke simulation : so the piston line - boundary move to compless inside fluid using the UDF

[arep_24]

hello bigben,

here my email, arifmsohaimi@gmail.com

[sdsuronnie]

Originally Posted by BigBen

There are 3 differents moving mesh. Which one are you using: Remeshing/deforming/layering?
Give me your email, I may have some pictures showing how to do it.

Hello，Mr. BigBen

I am having the same dynamic mesh problem too.

Best regard

Ronnie

sdsuronnie@gmail.com

[ganeshhr555]

Dear Bigben,

Am working on Gerotor oil pump analysis , Am facing a negative cell volume error while doing a preview mesh motion.

I want to know is it any command is available to display or view a negative cell to redefine my mesh again.

Regards,
Ganesh.t
ganesh.t@sfl.co.in

[Kubilay BAYRAMOĞLU]

Originally Posted by BigBen

Reffering to ur picture, ur mesh is purely hexa/quad, only layering can be applied starting at the botom of the "Piston".
Did you mesh the piston thickness? (just for understanding)

If you want to remesh your volume, you need to mesh it in tetra and not in quad.

So what did you do?
When is the error appearing?

please, send me email for this problem solutions
k.bayramoglu.b@gmail.com

[samm69]

Originally Posted by BigBen

There are 3 differents moving mesh. Which one are you using: Remeshing/deforming/layering?
Give me your email, I may have some pictures showing how to do it.

Please suggest me some solutions.
Sir, my email id is saumyaranjan.nayak93@gmail.com