|
[Sponsors] |
![]() |
![]() |
#21 | |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Quote:
Do you have email, I can send you a file. |
||
![]() |
![]() |
![]() |
![]() |
#22 |
Senior Member
|
Is there any particular reason for using Explicit VOF? If you are modeling a falling film and the film is quite thin, better to use Eulerian Wall Film model. Modeling a thin film with VOF is always expensive. Other option is to use Implicit VOF along with LSM to improve accuracy.
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#23 | |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Quote:
(2)I do not know how I can use a Eulerian Wall film model, can you tell me how I can set it? Or I can send my case to you. If you are available, I can send you by email. For the forum can not submit a file exceed 195.3 Kb. (3)What is the LSM, how can choose the Implicit VOF along with LSM. Thank you very much for your reply. |
||
![]() |
![]() |
![]() |
![]() |
#24 |
Senior Member
|
Geo-Reconstruct is the best reconstruction algorithm available in Fluent, however, CICSAM is good as well and is available with implicit VOF.
EWF is a separate model under Models. But it is not available under older versions. I suppose this is available starting from R14. LSM is level set method. It is not available as a stand-alone model in Fluent but in combination with VOF. This is useful for scenarios that have significant surface tension.
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#25 | |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Quote:
|
||
![]() |
![]() |
![]() |
![]() |
#26 |
Senior Member
|
Transient formulation in Fluent's pressure based solver is always implicit. Implicit means that VOF capturing is implicit.
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#27 |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
But we I choose the implicit VOF capturing, there is no CSCSAM option for the volume fraction, there are only "compressive" and "modified HRIC" optiions. Only I use explicit VOF capturing can I choose the CSCSAM option.
|
|
![]() |
![]() |
![]() |
![]() |
#28 |
Senior Member
|
In place of CICSAM, use compressive.
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#29 |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
||
![]() |
![]() |
![]() |
![]() |
#30 |
Senior Member
|
As stated earlier, Geo-reconstruct is the best available option. However, this is about reconstruction of the interface. Capturing depends a lot on the mesh. If the mesh is fine enough, results will be acceptable. If the film thickness is less than 1 mm, I'd recommend using EWF instead of VOF.
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#31 | |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Quote:
|
||
![]() |
![]() |
![]() |
![]() |
#32 |
Senior Member
|
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#33 | |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Quote:
|
||
![]() |
![]() |
![]() |
![]() |
#34 |
Senior Member
|
VOF is applicable as long as N-S is applicable, however, it becomes very expensive since a very fine mesh, spatial as well as temporal, is required. EWF can be used as long as film thickness is lesser than first cell height. So, you would need a coarser mesh. 1 mm is just a recommended value, you can use EWF for thicker films as well.
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#35 | |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Quote:
|
||
![]() |
![]() |
![]() |
![]() |
#36 |
Senior Member
|
For normal flows, mesh size is usually selected on the basis of
![]()
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#37 |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Do you know why the mesh is not uniform(see the attachment) around the tube surface?
|
|
![]() |
![]() |
![]() |
![]() |
#38 |
Senior Member
|
The mesh is already as uniform as it can get. It's the height of first cell and the growth rate that matters.
__________________
Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority. |
|
![]() |
![]() |
![]() |
![]() |
#39 |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
You mean it is reasonable for this phenomenon, I can not understand, but I find that the mesh in the article have not the phenomenon, why?
|
|
![]() |
![]() |
![]() |
![]() |
#40 | |
Senior Member
Join Date: Dec 2017
Posts: 388
Rep Power: 9 ![]() |
Quote:
Collection efficiency calculation and running wet and runback analysis on wing Copy the files, (NACA_0012.msh, film_accretion.c) to the working folder. Thank you for sending me[/QUOTE] |
||
![]() |
![]() |
![]() |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Courant number | fireman | FLUENT | 7 | September 11, 2021 11:33 |
same geometry,structured and unstructured mesh,different behaviour. | sharonyue | OpenFOAM Running, Solving & CFD | 13 | January 2, 2013 22:40 |
air bubble is disappear increasing time using vof | xujjun | CFX | 9 | June 9, 2009 07:59 |
LES near wall model & courant number | kasim | CFX | 5 | March 16, 2008 18:23 |
IcoFoam parallel woes | msrinath80 | OpenFOAM Running, Solving & CFD | 9 | July 22, 2007 02:58 |