|
[Sponsors] |
when I use multi block the condition of stability can not be fulfilled |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
February 10, 2012, 07:28 |
when I use multi block the condition of stability can not be fulfilled
|
#1 |
New Member
www.manvatoo.com
Join Date: Nov 2011
Posts: 5
Rep Power: 14 |
The run with :2 block(multi block) . time :49 & 50s ===>>> we haven’t the condition of stability
================= The run with: one block. time :49 & 50s ===>>>we have the condition of stability =============== Hello Im working on flip bucket. As you illustrated in the pictures, when I use multi block the condition of stability can not be fulfilled, but in one block im able to reach the condition of stability. As you know,one block simulation is time consumption I want to know there is away to reach the condition of stability by using multi-block? I want to know where I made mistake.i wonder if my friends could possibly make it crystal clear? Best regards. |
|
February 10, 2012, 13:12 |
|
#2 |
New Member
www.manvatoo.com
Join Date: Nov 2011
Posts: 5
Rep Power: 14 |
new run with new meshing
3block-linked : there is that problem the condition of stability can not be fulfilled details: block N.1 : cell size=1 cm block N.2(on flip bucket) : cell size= 0.6 cm block N.3 : cell size=1 cm t:60s |
|
April 19, 2012, 13:17 |
|
#3 |
Senior Member
Jeff Burnham
Join Date: Apr 2010
Posts: 204
Rep Power: 17 |
The cells should be even multiples of those in the adjacent block. That is, your flip-bucket block should have cells that are 0.5 units long (cubes are best), not 0.6. FLOW-3D interpolates results between mesh blocks; if the cell grid lines don't line up exactly, then interpolation leads to momentum diffusion and stability difficulties (pressure solver).
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
CFL Condition | Matt Umbel | Main CFD Forum | 19 | June 30, 2020 09:20 |
stability condition for 4th order of CD | qunwuhe@hotmail.com | Main CFD Forum | 1 | April 20, 2008 18:35 |
Stability Condition for Immersed Boundary Method | Dave Rudolf | Main CFD Forum | 0 | February 6, 2007 00:36 |
On LBB stability condition | Yang Cao | Main CFD Forum | 1 | June 21, 2006 07:10 |
stability condition | manfred krueger | Main CFD Forum | 2 | March 8, 2001 14:20 |