[oozcan]

Hi all,

I would like to make all residuals compatible with convergence tolerance.

But continuity equations residuals always acts as exact opposite.
Still energy equation is deactivated. I am going to activate following all residuals converge.

Anyone who help me will be appreciated !

[Kushal Puri]

Can you provide the complete description of the problem.

[oozcan]

Originally Posted by Kushal Puri

Can you provide the complete description of the problem.

ok,well, I am going to work on temperature distribution of a solid material that is one of 7 bodies. I have corrected some negligible something in DM (and form new part has been done to provide for structured mesh) and mesh all multi-body part in ANSYS-Meshing.

Skewness :0.88
Orthogonal quality min:0.17
Max aspect ratio :42
Elements : about 2.5 millions.

So, As for FLUENT,

energy eq is activated but equation will be activated following some residualls goes down (here is I ask question that is reason for I posted.)

Turbulence model: k-epsilon-realizable-enhanced wall functions ) (y+=3, I choose), because first layer thickness was so minimal for y+=1: now, first layer thicknesses : 0,003 m and 0,004 m for two wet areas.(calculated seperately)

PV= Coupled, discretization schemes are all first upwind (AMG divergence detectedgave me always error in this project because of ''SECOND ORDER UPWIND''),pressure is standard and PRESTO! have been tried,

All tests I have done gave me same residuals behavior in beginning of every solving. That's why I put screen shot ''attached''.

100,200,sometimes 50. iterations give me AMG divergence detected ''k'' someties ''e''. I think residual behavior is relevant to that error. I am sure that boundary conditions and mesh are ok

[LuckyTran]

What do you mean by continuity behaves opposite? It seems to be doing the same as all the other residuals (it spikes at 5 or so iterations and then gradually reduces).

Be aware though that continuity is not scaled the same way as other variables. Continuity is scaled based on the maximum residual that occurs within the first five iterations.

[oozcan]

Originally Posted by LuckyTran

What do you mean by continuity behaves opposite? It seems to be doing the same as all the other residuals (it spikes at 5 or so iterations and then gradually reduces).

Be aware though that continuity is not scaled the same way as other variables. Continuity is scaled based on the maximum residual that occurs within the first five iterations.

I have to activate '' energy equation in about 90. iterations. It is already seen ''variance''.

As far as I know, energy equation must be activated following flow and turbulence equations get converged. How can I provide same behaviour in all residuals? ( especially continuity)