[bhanu]

hi all,
i am working on a rotating disk in a cylinder and the problem is i am not getting what i should use to rotate my disk. i have got half cylinder filled with water and half is air.everything is stationary except my disk that is moving rotational. i am working to see the film formation on a disk and want to see the disk rotate as it's make film on it...
if any body can help me with that, i would be so delighted and thankful.

[-mAx-]

with which software did you mesh your geometry?
pictures may help

[bhanu]

hi max,
i have used gambit for modeling and meshing and my meshing is also an another issue that i am not able to do a good meshing so if you can help me with meshing would be great. here i am attaching the picture of model with meshing and without meshing.Untitled.jpg

rotating disk.jpg

[bhanu]

the model without meshingUntitled.jpg

[-mAx-]

if you want rotate your mesh, then rotor and stator have to be disconnected.
In Gambit pick and move rotor volume anywhere. If you can then rotor and stator are disconnected.
If you cannot (error message), it means they are connected

Once it is done you have to define interfaces for being able to use sliding mesh

[bhanu]

Yeah my rotor and stator are disconnected and i have used interface system. Let me clear it first i made my disk first than i subtracted from a bit bigger disk. That is aside and than i made cylinder and one same size of bigger disk and than an outer cylinder. Split both cylinders and than substract disk from inner cylinder so that's how i got interfaces.

[-mAx-]

can you provide your *.dbs file?

[bhanu]

yeah for sure but i don't know how to send that file here???

[bhanu]

can you give me your mail id so i can send you tht file through my mail??

[-mAx-]

upload it on a share server, like dropbox or whatever

[bhanu]

https://www.dropbox.com/s/nkmx0pfxttfy1t3/bhanu.dbs
if you can suggest me something for meshing that would be great

[-mAx-]

you only defined one fluid domain "wa&li"
Actually you need 2 if you want rotate your impeller: stator and stator.
If I see you interface, you should set volume.2 & volume.7 as rotor.

[bhanu]

Yeah i tried that one as well but that means i am rotating the fluid and that is not i want cause in my case only the disk is rotating and fluid is stable. And i am trying to get good meshing on it do you have any suggestion for tht ???

[-mAx-]

Originally Posted by bhanu

Yeah i tried that one as well but that means i am rotating the fluid

Wrong !
Since you didn't set anything in fluent, you cannot say that rotor is "moving" and stator is fixed.
At this point you are only ready to treat 2 separated zones.

[bhanu]

but i have given the boundary condition in fluent for my disk that moves my disk. in that i have given rotational speed for my disk. but if i make another cell zone condition for my disk and if i than give the mesh motion that means i am rotating my fluid at the disk position. !!!

[bhanu]

if you please have a look on this file you might will understand what i am trying to say https://www.dropbox.com/s/061a97nopo9fzyp/bhanu.cas

[-mAx-]

Originally Posted by bhanu

if you please have a look on this file you might will understand what i am trying to say https://www.dropbox.com/s/061a97nopo9fzyp/bhanu.cas

I don't have fluent (anymore)

Originally Posted by bhanu

but i have given the boundary condition in fluent for my disk that moves my disk. in that i have given rotational speed for my disk. but if i make another cell zone condition for my disk and if i than give the mesh motion that means i am rotating my fluid at the disk position. !!!

Don't mix rotational speed at wall (BC) for a static mesh with rotional-sliding mesh (dynamic mesh)
In your case, if you want to move you rmesh you have to enable the dynamic mesh option, and you will set the rotor domain as moving with a rotational speed (not only the wall, but also the rotor --> that's why you disconnected the rotor from stator)

[anbu2cfd]

Use sliding mesh interface,between your rotor and stator and specify the angular velocity for the disc. in cell zone conditions you have to enable the frame motion and copy those settings to mesh motion. interfaces should be define properly between the sliding. As max saying you can use dynamic mesh tool or sliding mesh to complete your task.

[bhanu]

can you tell me how can i start dynamic mesh and what i have to do in that?

[bhanu]

can you tell me how can i give rotational speed in dynamic mesh???? there is no option such like that !!!!!!!