CFD Online Logo CFD Online URL
Home > Forums > FLUENT

k residual goes up after temperature limitation warning???

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

LinkBack Thread Tools Display Modes
Old   November 24, 2010, 18:48
Default k residual goes up after temperature limitation warning???
Join Date: May 2010
Posts: 57
Rep Power: 9
Catthan is on a distinguished road
Dear all,

I am modelling the combustion of methane-air in a stirling engine burner and after, say, 65 iterations and while all residuals decrease i get the temperature limitation (limited to 1K) warning and once I get it the k residual starts to increase (while all the rest keep going down).
At the moment the warning is restricted to 1 to 3 cells.

What I am using is the species transport with no reactions yet activated and the realizable k-ε turbulence model.

The solution is steady state.

I can tell that solution is at an early stage by a velocity monitor in my outlet which has not yet stabilised.

I understand it might be too early to worry but I think whatever is wrong has started affecting other cells

I am using a very fine tetra mesh with prism layers on the walls.

my bocos are:

mass flow inlet for my air and gas inlets with turbulence specification set to intensity and ratio - default values of 10% for both

outflow for my exhaust

coupled walls for components inside the burner where I must later compute conjugate heat transfer

0 heat flux for all other walls (e. g. the base of the burner)

I am running this huge case on a super computer facility and I am a bit pressed in time so any suggestions would be most appreciated

All the best
Catthan is offline   Reply With Quote


Thread Tools
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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
transsonic nozzle with rhoSimpleFoam Unseen OpenFOAM Running, Solving & CFD 7 April 16, 2014 03:38
How to write k and epsilon before the abnormal end xiuying OpenFOAM Running, Solving & CFD 8 August 27, 2013 15:33
Floating point exception error Alan OpenFOAM Running, Solving & CFD 10 April 6, 2012 14:02
Differences between serial and parallel runs carsten OpenFOAM Bugs 11 September 12, 2008 11:16
Unknown error sivakumar OpenFOAM Pre-Processing 9 September 9, 2008 12:53

All times are GMT -4. The time now is 03:51.