CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Phoenics

Residuals and .result files

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

LinkBack Thread Tools Display Modes
Old   February 3, 2010, 07:02
Default Residuals and .result files
New Member
Hans Peter Jensen
Join Date: Feb 2010
Posts: 1
Rep Power: 0
HPJE is on a distinguished road

I'm using Phoenics as part of WindSim. I'm trying to figure out ways of checking convergence after a run has been completed by using the .result file I get from Phoenics.

Using the MIGAL solver, I get a list of residuals (Max, Min and RMS) for each iteration. Would it be appropriate to use these values to check convergence? I'm concerned whether the values provided are whole-field values or stems from a single location? Also, Which variable are the residuals showing; just the overall largest and smallest?

Further, can somebody help me understand the section shown below? I'm having trouble deciphering it.

************************************************** **********
Whole-field residuals before solution
with resref values determined by EARTH
& resfac= 1.000000E-01
variable resref (res sum)/resref (res sum)
P1 1.232E+05 1.383E-02 1.703E+03
U1 1.137E+06 2.078E-02 2.363E+04
V1 6.845E+03 7.748E-01 5.303E+03
W1 2.626E+04 5.407E-01 1.420E+04
KE 3.566E+03 6.060E-01 2.161E+03
EP 3.189E+01 5.820E-01 1.856E+01

************************************************** **********

Thanks for your help guys. Any comments are appreciated. And sorry if I'm asking stupid questions ;-)
HPJE is offline   Reply With Quote

Old   February 5, 2010, 06:07
New Member
Join Date: May 2009
Location: Germany
Posts: 25
Rep Power: 10
Linh.Hoang is on a distinguished road
Hello Hans Peter,
iīm not using MIGAL Solver but hope I can help you anyway. I check convergence after run by reading the hole field residuals in the result file. To be honest I donīt know how Phoenics calculate the resref so I take the res sum (hole field residual) and normalise it with the inflow quantities. You got this information from the result file right after the residuals. there you take the nett source (pos. sum) and nomalise yor res sum for each variable with the corresponding nett source. Your normalised residual should drop in a Order of E-3 to reach Convergence.
Hope this helps
Linh.Hoang 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

All times are GMT -4. The time now is 04:48.