|
[Sponsors] |
low local continuity while high global continuity |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
June 15, 2013, 10:19 |
low local continuity while high global continuity
|
#1 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
what does low local continuity residual(1e-5)but high global(1e-18)mean?
Code:
DILUPBiCG: Solving for Ux, Initial residual = 0.0004256482273, Final residual = 3.42419877e-17, No Iterations 4 DILUPBiCG: Solving for Uy, Initial residual = 0.0008584110976, Final residual = 1.699508551e-16, No Iterations 4 DILUPBiCG: Solving for e, Initial residual = 0.0004690168561, Final residual = 4.48278334e-17, No Iterations 4 DILUPBiCG: Solving for p, Initial residual = 0.0004642938087, Final residual = 8.887120082e-17, No Iterations 4 diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0 time step continuity errors : sum local = 4.223753118e-06, global = -9.485719823e-18, cumulative = -4.473784803e-05 DILUPBiCG: Solving for p, Initial residual = 3.306483671e-07, Final residual = 6.449921349e-17, No Iterations 3 diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0 time step continuity errors : sum local = 4.21218922e-06, global = -9.149711212e-18, cumulative = -4.473784803e-05 DILUPBiCG: Solving for omega, Initial residual = 0.0003045968168, Final residual = 4.305610069e-16, No Iterations 4 DILUPBiCG: Solving for k, Initial residual = 0.0008443110421, Final residual = 9.851206562e-18, No Iterations 5
__________________
Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
|
June 16, 2013, 09:12 |
|
#2 | ||
Retired Super Moderator
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,975
Blog Entries: 45
Rep Power: 128 |
Hi Ehsan,
Quote:
Almost a month ago, you had asked me about adding continuity to rhoCentralFoam. In one of the emails, I had sent the following explanation: Quote:
Best regards, Bruno
__________________
|
|||
June 16, 2013, 09:32 |
|
#3 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 26 |
Hi Bruno
I meant the accuracy.local has low accuracy.maybe wasn't careful enough! rhoCentralFoam hasn't any difficulty in relation to continuity.both local and global continuity residuals are low enough,these results are from sonicFoam.
__________________
Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
|
June 16, 2013, 12:25 |
|
#4 |
Retired Super Moderator
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,975
Blog Entries: 45
Rep Power: 128 |
rhoCentralFoam does things in a very different way, at least from what I've vaguely read about it. If I'm not mistaken, it tends to smooth out the values (because it's "central", it takes into account more values from it's sides and the previous times?), which would be why the continuity would be well preserved.
But sonicFoam doesn't have this feature that rhoCentralFoam has got, which is probably why you're seeing larger continuity issues. Try reducing the "deltaT", to see if it has any effect. If it doesn't, then "fvSchemes" and the mesh itself should perhaps be the ones to blame?
__________________
|
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Floating point exception error | Alan | OpenFOAM Running, Solving & CFD | 11 | July 1, 2021 21:51 |
SLTS+rhoPisoFoam: what is rDeltaT??? | nileshjrane | OpenFOAM Running, Solving & CFD | 4 | February 25, 2013 04:13 |
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 | bookie56 | OpenFOAM Installation | 8 | August 13, 2011 04:03 |
Orifice Plate with a fully developed flow - Problems with convergence | jonmec | OpenFOAM Running, Solving & CFD | 3 | July 28, 2011 05:24 |
Full pipe 3D using icoFoam | cyberbrain | OpenFOAM | 4 | March 16, 2011 09:20 |