|
[Sponsors] |
Problem running a steady state case using simpleFoam |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
August 1, 2022, 08:31 |
Problem running a steady state case using simpleFoam
|
#1 |
New Member
Smruti Ranjan Jena
Join Date: Jan 2017
Location: Odisha, India
Posts: 5
Rep Power: 9 |
Hi Everyone,
At present I am trying to simulate the case of flow past a square cylinder at Re=10 using simpleFoam (v20.12). As I am trying to run a steady laminar flow case, I have changed the simulationType from default RAS to "laminar" in the constant/turbulenceProperties file and all other input data are left untouched. However, when I look at the drag coefficients value after running it for t_end=100000, it seems like the code has diverged as I get Cd value of the order 1.0e+9. I am sure grid & timestep doesn't have any issues at all. I would truly appreciate any kind of suggestions by the community. Regards, Smruti |
|
August 1, 2022, 10:04 |
|
#3 |
New Member
Smruti Ranjan Jena
Join Date: Jan 2017
Location: Odisha, India
Posts: 5
Rep Power: 9 |
Thanks for your reply.
I could open the log file where I am saving all the output residuals, but if I could print those residuals (of Ux, Uy and p) vs the iteration counter then that would be great. Any ideas or suggestions? I would also like to know why did you suggest to look into residual norms? Thanks, Smruti |
|
August 1, 2022, 12:08 |
|
#4 |
Senior Member
|
Residual norms are likely more informative than drag coefficient.
Plotting the residual norm of various fields vs. iteration number * write residual norms of the various fields to file instead of to screen. Do so using so-called unix pipe command, e.g., simpleFoam >& log.simpleFoam or use the runApplication utility instead (typically inside of Allrun); * use foamLog utility to generate the the logs-directory in the case directory; foamLog runs a bunch of scripting commands to read data from the log-file and reorders the information in separate files; * use gnuplot to load and plot the data in the logs-directory: in separate terminal run ./myplot. See sample myplot file below Sample myplot file to plot residual norm vs. iteration number #!/bin/bash # Requires running foamLog <log-file> first!! gnuplot -persist >/dev/null 2>&2 << EOF set logscale y plot "logs/UxFinalRes_0" with lines, \ "logs/UyFinalRes_0" with lines, \ "logs/UzFinalRes_0" with lines, \ "logs/pFinalRes_0" with lines, \ "logs/kFinalRes_0" with lines, \ "logs/epsilonFinalRes_0" with lines |
|
Tags |
openfaom, simplefoam, square cylinder, steady state |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Upwind Scheme Steady State Problem | ugurtan666 | SU2 | 0 | January 19, 2022 09:42 |
mass flow in is not equal to mass flow out | saii | CFX | 12 | March 19, 2018 06:21 |
Problem running simpleFoam on a multi element airfoil | vinz | OpenFOAM Running, Solving & CFD | 18 | April 11, 2013 12:26 |
transient problem run in steady state | luigi | FLUENT | 4 | March 13, 2008 07:54 |
About the difference between steady and unsteady problems | Lisa | Main CFD Forum | 11 | July 5, 2000 15:37 |