[gschaider]

Hi!

The warnings are from gnuplot they mean "you've given me a series (t_n,y_n) were all y_n have the same value, I'll extend the y-range to [y_n-eps,y_+eps]", but something should be plotted anyway (if there are more than two timesteps in the logfile). One problem could be that the watcher waits for a timestep that never comes before plotting. Try playing around with --tail to fix that.

Could you give me more information about the Logfile you're trying to process?

Bernhard

[kumar]

Hi ,
I am using lesInterFOAM to run my simulations. I want to plot my residuals and check if my solution is converged or not.
I found that there are two ways to do that
I used the PyFOAMPlotwatcher.py log_file to plot my log file, but it gave me the three plots
1)Residuals vs time steps (unstaedy calculation)
2)continuity vs cummulative and global
3)Bounded variables (K_min,k_max,K-avg)

I cannot understand the significance of the first two plots, could somebody explain to me the first two plots in terms of convergence with respect to OpenFOAM

I also used the foamlog script to make a directory which has the relevant data. But How do I plot them correctly.

since i am a new user any help will be appreciated
bye

[kumar]

Hi,
I used the foamLog command on my log file and I got the logs directory. The directory contains files pd_0,pd_1,pdIters_0,pdIters_1,pdfinalRes_0,pdFinal Res_1

I used xmgrace to plot these files,
but i want to be sure what each of these files correspond to,
for eg if i want to see the final residual of my pressure correction equation and pressure equation(pd) over time step which files do I have to plot.

bye

[kumar]

I have made a residuals plot using the PythonPlotwatcher.py on my log file, but can somebody explain what this script plots from the log file, just a brief explanation is sufficient

if required i can send the plot as well

how do i post my graph on this message space.


bye
with regards
K.Suresh kumar

[kumar]

Hello everybody,

I need some help in understanding the log file. I am using lesInterfoam for simulation of liquid being injected in to a chamber under pressure difference

Courant Number mean: 0.0031196519 max: 0.4989031
deltaT = 8.5500283e-09
Time = 3.770929904e-05

MULES: Solving for gamma
Liquid phase volume fraction = 0.0015046647 Min(gamma) = -5.2829736e-11 Max(gamma) = 1
MULES: Solving for gamma
Liquid phase volume fraction = 0.0015048032 Min(gamma) = -1.0746907e-11 Max(gamma) = 1
MULES: Solving for gamma
Liquid phase volume fraction = 0.0015049417 Min(gamma) = -5.7332803e-11 Max(gamma) = 1
smoothSolver: Solving for k, Initial residual = 0.00045105006, Final residual = 8.3348678e-08, No Iterations 3
bounding k, min: -1.2895711e-09 max: 12308.897 average: 94.35856
smoothSolver: Solving for Ux, Initial residual = 0.01244294, Final residual = 8.2049502e-07, No Iterations 3
smoothSolver: Solving for Uy, Initial residual = 0.0026720077, Final residual = 1.3961205e-07, No Iterations 3
smoothSolver: Solving for Uz, Initial residual = 0.030640138, Final residual = 6.3619817e-08, No Iterations 4
GAMG: Solving for pd, Initial residual = 0.33910157, Final residual = 0.0029885117, No Iterations 12
GAMGPCG: Solving for pd, Initial residual = 0.015574446, Final residual = 6.190298e-07, No Iterations 61
time step continuity errors : sum local = 1.0611522e-11, global = -2.129606e-13, cumulative = -3.2031832e-10
ExecutionTime = 64859.16 s ClockTime = 64890 s

Courant Number mean: 0.003118677 max: 0.49893967
deltaT = 8.5500283e-09
Time = 3.771784907e-05

MULES: Solving for gamma
Liquid phase volume fraction = 0.0015050802 Min(gamma) = -4.7481924e-11 Max(gamma) = 1
MULES: Solving for gamma
Liquid phase volume fraction = 0.0015052187 Min(gamma) = -5.7624764e-12 Max(gamma) = 1
MULES: Solving for gamma
Liquid phase volume fraction = 0.0015053572 Min(gamma) = -1.4955086e-11 Max(gamma) = 1
smoothSolver: Solving for k, Initial residual = 0.00044780268, Final residual = 8.0865222e-08, No Iterations 3
bounding k, min: -1.5803901e-09 max: 12310.74 average: 94.450017
smoothSolver: Solving for Ux, Initial residual = 0.012391458, Final residual = 8.2098518e-07, No Iterations 3
smoothSolver: Solving for Uy, Initial residual = 0.0026448201, Final residual = 1.3871489e-07, No Iterations 3
smoothSolver: Solving for Uz, Initial residual = 0.030546766, Final residual = 6.7991922e-08, No Iterations 4
GAMG: Solving for pd, Initial residual = 0.32492639, Final residual = 0.0031413767, No Iterations 8
GAMGPCG: Solving for pd, Initial residual = 0.014844994, Final residual = 7.1476504e-07, No Iterations 61
time step continuity errors : sum local = 1.2763008e-11, global = 5.349711e-15, cumulative = -3.2031297e-10
ExecutionTime = 64881.31 s ClockTime = 64912 s

From the details of my log file as posted above i can see that my gamma value is bounded between -4.74881 and 1.
the final residual for k shows that k is converging to 8.0e-08. which is fine .

the Ux, Uy and Uz are also fine.

My only concern is about the pd
can anybody explain the first line GAMG:solving for pd where the final residual is 0.00314137767, which i think is not satisfying to me.
also what does the second line GAMGPCG:solving for pd correspond to where the final residual is 7.14e-07.

From the time step continuity errors i understand that my continutiy equation is converged to 1.27e-11. I have also managed to plot the log file using PyFOAMPlotwatcher.py, but i need some idea about the log file.
bye
K.Suresh kumar

[lakeat]

Originally Posted by santos

Hi Ivan,

I am using Bernhard PyFoam tools to monitor the residuals in OpenFOAM 1.5 as follows:

simpleFoam > log &
pyFoamPlotWatcher.py log

That's exactly what I need! Thank you Jose, and thank you Bernhard!

[wolle1982]

Plotting Residuals (or forces) on the fly with gnuplot without any further pyFOAM problems see my tutorial under http://www.cfd-online.com/Forums/ope...residuals.html

[jackpap]

PyFoam-bin/lib64/python2.6/site-packages/PyFoam/FoamInformation.py:5: DeprecationWarning: The popen2 module is deprecated. Use the subprocess module.
from popen2 import popen4
Warning: empty x range [1:1], adjusting to [0.99:1.01]
Warning: empty y range [-0.000908794:-0.000908794], adjusting to [-0.000899706:-0.000917882]
Warning: empty y2 range [-0.000908794:-0.000908794], adjusting to [-0.000899706:-0.000917882]
Warning: empty x range [1:1], adjusting to [0.99:1.01]


I'm having the same kind of problem when running pyFoamPlotWatcher
I have just installed the svn version of PyFoam and I'm running Foam 1.5.
I am also running in OpenSuse :

-> Linux 2.6.27.23-0.1-default (openSUSE 11.1)
-> Python 2.6
-> gnuplot 4.2 patchlevel 3

--> Also the funny thing is when I use the options to write out the residuals in a file , the files are output without a problem and list all the timesteps...


Any help appreciated.

[gschaider]

Originally Posted by jackpap

PyFoam-bin/lib64/python2.6/site-packages/PyFoam/FoamInformation.py:5: DeprecationWarning: The popen2 module is deprecated. Use the subprocess module.
from popen2 import popen4
Warning: empty x range [1:1], adjusting to [0.99:1.01]
Warning: empty y range [-0.000908794:-0.000908794], adjusting to [-0.000899706:-0.000917882]
Warning: empty y2 range [-0.000908794:-0.000908794], adjusting to [-0.000899706:-0.000917882]
Warning: empty x range [1:1], adjusting to [0.99:1.01]


I'm having the same kind of problem when running pyFoamPlotWatcher
I have just installed the svn version of PyFoam and I'm running Foam 1.5.
I am also running in OpenSuse :

-> Linux 2.6.27.23-0.1-default (openSUSE 11.1)
-> Python 2.6
-> gnuplot 4.2 patchlevel 3

--> Also the funny thing is when I use the options to write out the residuals in a file , the files are output without a problem and list all the timesteps...


Any help appreciated.

The deprecated warning shouldn't be a problem (and it will be fixed in the next release). The empty-range stuff is gnuplot (if all the points in a set have the same value). The not-appearing of plot-windows is strange (and usually occurs on SuSe-machines). One test: add the --hardcopy-option and check whether any PNG or PS (depends on the version) are created.

Bernhard

[rajeshkunwar]

Hi All.

I am using buoyantPimpleFoam and the residuals of k_0, Ux_0 are fluctuating and does not come down ( I mean below 1e-5). I am running on a very fine mesh. What could be the problem.

Rajesh