|
[Sponsors] |
January 5, 2009, 09:34 |
reducing grid size
|
#1 |
Guest
Posts: n/a
|
Looking at droplet (17.5 mu) impact on porous media (d = 50nm)in 2D for different grid sizes, the time where equilibrium is reached significantly differs (as too the solution). Using a grid size of 1/2 mu leads to lots of absorption and no further fluid penetration up to t = 0.8 seconds. As I reduce the grid size to 1/6 mu absorption stops around t = 7e-4 seconds and only very little absorbtion is observed. As I decrease the grid size I suspect (hope) the solution to converge eventually, but have you got any idea of the grid size I should adopt in order to model this problem properly? Also, when reaching this 'equilibrium solution', the total volume decreases tremendously. Can you help me with this?
|
|
January 9, 2009, 00:25 |
Re: reducing grid size
|
#2 |
Guest
Posts: n/a
|
Hi Marjon,
What physical and numerical options are you using? Any implicit solvers other than for the pressure? Michael |
|
January 9, 2009, 03:51 |
Re: reducing grid size
|
#3 |
Guest
Posts: n/a
|
All explicit solvers and the SOR method for pressure, no heat transfer, itb=1, iwsh=1, ifsft=1, ifvisc=1, icmprs=0 and cfpk=0.1. Calculation is in 2D as I am using just 1 grid cell in y-direction with symmetrical boundary conditions. Capillary pressure equals 1120000 (d= 50nm and theta=30), porosity = 0.40. Can you help me?
|
|
January 9, 2009, 10:52 |
Re: reducing grid size
|
#4 |
Guest
Posts: n/a
|
Thanks, Marjon. What is the drag model and the drag coefficient for the porous media? Are you using capillary pressure in the porous media?
It is hard to pinpoint the problem without seeing the results or running the problem. Have you tried contacting the support? Michael |
|
January 12, 2009, 09:18 |
Re: reducing grid size
|
#5 |
Guest
Posts: n/a
|
I am using the Reynolds Number Dependent Drag model and capillary pressure in the porous medium (1120000). I shall send you my prepin file by email.
Hope to hearing from you soon. Marjon |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
first grid size for a given y-lus | morteza08 | Main CFD Forum | 3 | February 3, 2011 12:05 |
OF 1.6 | Ubuntu 9.10 (64bit) | GLIBCXX_3.4.11 not found | piprus | OpenFOAM Installation | 22 | February 25, 2010 13:43 |
increasing grid size | kcg | Siemens | 5 | April 8, 2007 18:26 |
grid size in LES | michael | Siemens | 0 | December 26, 2006 23:02 |
Grid size and combustion simulation | versi | Main CFD Forum | 4 | February 16, 2004 06:42 |