CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Pre-Processing

what are the best solvers for P, U, cellDisplacement for overPimpleDyMFoam

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree2Likes
  • 1 Post By Swift

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 21, 2019, 21:40
Exclamation what are the best solvers for P, U, cellDisplacement for overPimpleDyMFoam
  #1
New Member
 
H.Ham
Join Date: Mar 2019
Posts: 21
Rep Power: 7
kimou is on a distinguished road
Hi Guys,

I am a new Openfoam user, and i am currently working on flow around an airfoil profile (externel flow). I work with overPimpleDyMFoam (transient regime), my mesh is 100k cells (using overSet Mesh) my problem is that my simulation takes a lot of time, to reach a duration of 0.2 second, my computer calculates during 2 days (it's huge time)

knowing that my current number maxCO = 8, and y + = 10.


Please help me !!!!!!!! please, !!!!!!
kimou is offline   Reply With Quote

Old   May 23, 2019, 05:50
Default
  #2
Member
 
Thomas Sprich
Join Date: Mar 2015
Posts: 76
Rep Power: 11
Swift is on a distinguished road
Hi Hamdani,

I think you are unlikely to get a best fit answer as often the choice of solver is subject to the type of geometry and determining the best choice is a case of trial and error.

I have used the following in a overInterDyMFoam simulation I ran:

Code:
"cellDisplacement.*"
    {
        solver          PCG;
        preconditioner  DIC;

        tolerance       1e-09;
        relTol          0;
        maxIter         100;
    }
and

Code:
    "(U|k|omega|epsilon).*"
    {
        solver          PBiCG;
        preconditioner DILU;
        tolerance       1e-015;
        relTol          0;
    }
I didn't have P, so I can't help you there. You might need to look at your tolerences to see if they are too rigid, particularly as you are starting the simulation. Also, I found it helps to have the background and overset meshes to be similarly sized.

You can always try reduce the size of the overset region. This should be minimised to reduce the number of cells that have to be calculated. I have read you need at least four cells around your geometry for overset. You could look at your mesh resolution, although this is probably a last resort.

Lastly, your courant number is quite high, test to see if lower values give you less iterations to your convergence for your Correctors. Maybe as your simulations stabilises you can increase the courant number.

If its any consolation, this simulation also took me a long time to solve.

I'm sorry I can't offer you a better answer than that.

Good luck,
Thomas
xiangxiang likes this.
Swift is offline   Reply With Quote

Old   May 23, 2019, 06:39
Default
  #3
New Member
 
H.Ham
Join Date: Mar 2019
Posts: 21
Rep Power: 7
kimou is on a distinguished road
HI Thomas,

thank you very much Thomas, I will take into consideration everything you said to me, you helped me very well

You will find attached "systeme folder "

-
yes I use the version v1812 which is compatible with oversetMesh
- My computer : Intel xeon 12 cores, RAM 32GB,

- Yes i'm running the simulation in parallel with :

----------------------------------

numberOfSubdomains 10;

method hierarchical;

coeffs
{
n (5 1 2);
delta 0.001; // default=0.001
//order xyz; // default=xzy
}
----------------------------------------

cfd_Online1.png

cfd_online2.jpg

checkMesh.jpg

solver.jpg

system.zip
kimou is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
OpenFOAM solvers for two-phase boiling flows Coris CFD Freelancers 1 May 22, 2019 04:54
Solid Mechanics Solvers added to OpenFOAM Extend bigphil OpenFOAM Announcements from Other Sources 26 October 12, 2017 05:01
Is there a difference between Riemann solvers and characteristic based solvers? linkamp Main CFD Forum 3 February 18, 2016 10:12
FSI solvers - best solvers steven123 OpenFOAM Running, Solving & CFD 0 July 8, 2014 11:26
Possible turbulence modelling bug in SRF solvers otm OpenFOAM Running, Solving & CFD 3 May 29, 2012 05:03


All times are GMT -4. The time now is 15:43.