# Sudden increase the residual of Maxwell's equations

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

 October 13, 2016, 04:22 Sudden increase the residual of Maxwell's equations #1 New Member   Zhen Join Date: Oct 2016 Posts: 4 Rep Power: 9 Hi guys, I am simulating free burning arc in open air. My model can run the DC arc current of 5 kA and arcing time 10 ms. But for arc time 5 kA and 100 ms, it can run another 100 ms after the arcing time and then it crashes. After I check the out file, I find there is an sudden increase of the residual of Maxwell's equaions. It is understandable that after the arcing time, there is no more current input and any other energy input, therefore the Maxwell's equations will stops calculation gradually. To prevent the fault extrapolation, I add a step function to the current input to make sure that the current input stays 0 after the arcing time. I also changed the timestep from 1e-3 and 1e-4 but still crash at the same time. Does anyone have some solution for that? Thank you Timestep: 1e-4 Adaptive Timestepping Information | ---------------------------------------------------------------------- | Direction | Ratio | Last Value | Next Value | RMS Co | Max Co | +----------------+-------+------------+------------+--------+--------+ | Unchanged | 1.000 | 1.0000E-04 | 1.0000E-04 | 0.08 | 0.28 | +----------------+-------+------------+------------+--------+--------+ ================================================== ==================== TIME STEP = 4031 SIMULATION TIME = 2.0627E-01 CPU SECONDS = 1.015E+07 (THIS RUN: 1071 1.0139E-01 2.346E+06) ---------------------------------------------------------------------- COEFFICIENT LOOP ITERATION = 1 CPU SECONDS = 2.346E+06 ---------------------------------------------------------------------- | Equation | Rate | RMS Res | Max Res | Linear Solution | +----------------------+------+---------+---------+------------------+ | U-Mom | 0.89 | 6.9E-05 | 8.2E-04 | 4.7E-01 ok| | V-Mom | 0.92 | 6.7E-05 | 1.1E-03 | 4.8E-01 ok| | W-Mom | 0.85 | 1.9E-04 | 8.8E-04 | 4.7E-01 ok| | P-Mass | 1.00 | 2.1E-03 | 1.6E-02 | 12.5 7.3E-02 OK| +----------------------+------+---------+---------+------------------+ | Ax-Mag-Fluid Domain | 0.00 | 5.4-137 | 5.4E-70 | 0.0E+00 OK| | Ay-Mag-Fluid Domain | 0.00 | 7.8-137 | 8.7E-70 | 0.0E+00 OK| | Az-Mag-Fluid Domain | 0.00 | 1.4-136 | 8.5E-70 | 0.0E+00 OK| | Ax-Mag-Solid Domain | 0.00 | 1.5-136 | 1.1E-69 | 0.0E+00 OK| | Ay-Mag-Solid Domain | 0.00 | 2.1-136 | 1.2E-69 | 0.0E+00 OK| | Az-Mag-Solid Domain | 0.00 | 2.7-136 | 1.2E-69 | 0.0E+00 OK| | Ax-Mag-Solid Domain | 0.00 | 3.6E-72 | 4.1E-71 | 0.0E+00 OK| | Ay-Mag-Solid Domain | 0.00 | 5.0E-72 | 6.8E-71 | 0.0E+00 OK| | Az-Mag-Solid Domain | 0.00 | 2.3E-71 | 2.5E-70 | 5.2 0.0E+00 OK| +----------------------+------+---------+---------+------------------+ | E-Pot-Fluid Domain | 0.00 | 2.3E-91 | 1.7E-89 | 0.0E+00 OK| | E-Pot-Solid Domain E | 0.00 | 9.1-105 | 1.8-103 | 0.0E+00 OK| | E-Pot-Solid Domain E | 0.00 | 2.1-106 | 4.5-105 | 5.4 0.0E+00 OK| +----------------------+------+---------+---------+------------------+ | H-Energy | 1.00 | 4.7E-04 | 7.0E-03 | 2.4E-05 OK| | T-Energy-Solid Domai | 1.00 | 1.2E-05 | 4.1E-04 | 2.4E-05 OK| | T-Energy-Solid Domai | 1.00 | 5.5E-05 | 3.3E-04 | 5.5 2.4E-05 OK| +----------------------+------+---------+---------+------------------+ | K-TurbKE | 1.00 | 2.5E-04 | 2.7E-03 | 5.5 4.1E-05 OK| | E-Diss.K | 1.00 | 5.0E-05 | 1.2E-03 | 10.5 5.9E-07 OK| +----------------------+------+---------+---------+------------------+ ---------------------------------------------------------------------- COEFFICIENT LOOP ITERATION = 2 CPU SECONDS = 2.346E+06 ---------------------------------------------------------------------- | Equation | Rate | RMS Res | Max Res | Linear Solution | +----------------------+------+---------+---------+------------------+ | U-Mom | 1.35 | 9.3E-05 | 2.6E-03 | 5.5E-01 ok| | V-Mom | 1.35 | 9.0E-05 | 2.3E-03 | 5.8E-01 ok| | W-Mom | 0.51 | 9.8E-05 | 3.6E-03 | 5.2E-01 ok| | P-Mass | 2.70 | 5.7E-03 | 5.6E-02 | 12.5 7.6E-02 OK| +----------------------+------+---------+---------+------------------+ | Ax-Mag-Fluid Domain | 0.00 | 2.0-134 | 8.8E-69 | 0.0E+00 OK| | Ay-Mag-Fluid Domain | 0.00 | 2.2-134 | 1.3E-68 | 0.0E+00 OK| | Az-Mag-Fluid Domain | 0.00 | 6.9-134 | 1.6E-68 | 0.0E+00 OK| | Ax-Mag-Solid Domain | 0.00 | 1.7-134 | 3.4E-69 | 0.0E+00 OK| | Ay-Mag-Solid Domain | 0.00 | 2.2-134 | 6.8E-69 | 0.0E+00 OK| | Az-Mag-Solid Domain | 0.00 | 2.6-134 | 6.6E-69 | 0.0E+00 OK| | Ax-Mag-Solid Domain | 0.00 | 2.1E-71 | 1.3E-70 | 0.0E+00 OK| | Ay-Mag-Solid Domain | 0.00 | 2.8E-71 | 1.7E-70 | 0.0E+00 OK| | Az-Mag-Solid Domain | 0.00 | 1.9E-70 | 8.7E-70 | 5.2 0.0E+00 OK| +----------------------+------+---------+---------+------------------+ | E-Pot-Fluid Domain | 0.00 | 8.2E-78 | 7.6E-76 | 0.0E+00 OK| | E-Pot-Solid Domain E | 0.00 | 6.2E-91 | 4.4E-90 | 0.0E+00 OK| | E-Pot-Solid Domain E | 0.00 | 6.6E-78 | 7.7E-77 | 5.4 0.0E+00 OK| +----------------------+------+---------+---------+------------------+ | H-Energy | 0.31 | 1.5E-04 | 6.1E-03 | 1.1E-05 OK| | T-Energy-Solid Domai | 0.50 | 5.8E-06 | 2.0E-04 | 1.1E-05 OK| | T-Energy-Solid Domai | 0.50 | 2.7E-05 | 1.6E-04 | 5.5 1.1E-05 OK| +----------------------+------+---------+---------+------------------+ | K-TurbKE | 0.49 | 1.3E-04 | 2.7E-03 | 5.5 3.0E-05 OK| | E-Diss.K | 1.24 | 6.2E-05 | 2.3E-03 | 10.5 1.7E-06 OK| +----------------------+------+---------+---------+------------------+ ---------------------------------------------------------------------- COEFFICIENT LOOP ITERATION = 3 CPU SECONDS = 2.347E+06 ---------------------------------------------------------------------- | Equation | Rate | RMS Res | Max Res | Linear Solution | +----------------------+------+---------+---------+------------------+ | U-Mom | 0.94 | 8.7E-05 | 2.3E-03 | 2.9E-01 ok| | V-Mom | 1.07 | 9.7E-05 | 3.4E-03 | 2.8E-01 ok| | W-Mom | 0.95 | 9.4E-05 | 4.7E-03 | 2.5E-01 ok| | P-Mass | 0.62 | 3.5E-03 | 6.4E-02 | 12.5 6.0E-02 OK| +----------------------+------+---------+---------+------------------+ | Ax-Mag-Fluid Domain | 0.00 | 3.8E-02 | 1.5E-02 | 3.9E-02 OK| | Ay-Mag-Fluid Domain | 0.00 | 4.1E-02 | 2.1E-02 | 5.8E-02 OK| | Az-Mag-Fluid Domain | 0.00 | 7.0E-02 | 2.7E-02 | 7.8E-02 OK| | Ax-Mag-Solid Domain | 0.00 | 2.4E-02 | 7.0E-03 | 3.9E-02 OK| | Ay-Mag-Solid Domain | 0.00 | 3.1E-02 | 1.1E-02 | 5.8E-02 OK| | Az-Mag-Solid Domain | 0.00 | 2.9E-02 | 8.7E-03 | 7.8E-02 OK| | Ax-Mag-Solid Domain | 0.00 | 5.4E-05 | 5.6E-04 | 3.9E-02 OK| | Ay-Mag-Solid Domain | 0.00 | 6.9E-05 | 5.8E-04 | 5.8E-02 OK| | Az-Mag-Solid Domain | 0.00 | 6.4E-04 | 2.4E-03 | 30.5 7.8E-02 OK| +----------------------+------+---------+---------+------------------+ +--------------------------------------------------------------------+ | ERROR #004100018 has occurred in subroutine FINMES. | | Message: | | Fatal overflow in linear solver. | +--------------------------------------------------------------------+ +--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | The ANSYS CFX solver could not be started, or exited with return | | code 255. No results file has been created. | +--------------------------------------------------------------------+ Timestep:1e-3 Adaptive Timestepping Information | ---------------------------------------------------------------------- | Direction | Ratio | Last Value | Next Value | RMS Co | Max Co | +----------------+-------+------------+------------+--------+--------+ | Decreasing | 0.800 | 1.0000E-03 | 8.0000E-04 | 0.85 | 2.88 | +----------------+-------+------------+------------+--------+--------+ ================================================== ==================== TIME STEP = 3158 SIMULATION TIME = 2.0626E-01 CPU SECONDS = 8.342E+06 (THIS RUN: 198 1.0138E-01 5.335E+05) ---------------------------------------------------------------------- COEFFICIENT LOOP ITERATION = 1 CPU SECONDS = 5.335E+05 ---------------------------------------------------------------------- | Equation | Rate | RMS Res | Max Res | Linear Solution | +----------------------+------+---------+---------+------------------+ | U-Mom | 1.01 | 2.4E-04 | 4.2E-03 | 8.8E-02 OK| | V-Mom | 0.95 | 2.4E-04 | 2.8E-03 | 8.2E-02 OK| | W-Mom | 1.22 | 5.6E-04 | 2.4E-03 | 6.7E-02 OK| | P-Mass | 0.96 | 6.6E-04 | 4.5E-03 | 31.6 8.1E-02 OK| +----------------------+------+---------+---------+------------------+ | Ax-Mag-Fluid Domain | 0.00 | 2.0E-02 | 7.4E-03 | 2.6E-02 OK| | Ay-Mag-Fluid Domain | 0.00 | 1.7E-02 | 8.4E-03 | 4.3E-02 OK| | Az-Mag-Fluid Domain | 0.00 | 8.3E-02 | 1.1E-02 | 9.3E-02 OK| | Ax-Mag-Solid Domain | 0.00 | 6.6E-03 | 3.9E-03 | 2.6E-02 OK| | Ay-Mag-Solid Domain | 0.00 | 1.4E-02 | 7.7E-03 | 4.3E-02 OK| | Az-Mag-Solid Domain | 0.00 | 1.9E-02 | 8.2E-03 | 9.3E-02 OK| | Ax-Mag-Solid Domain | 0.00 | 8.1E-05 | 6.2E-04 | 2.6E-02 OK| | Ay-Mag-Solid Domain | 0.00 | 7.7E-05 | 6.2E-04 | 4.3E-02 OK| | Az-Mag-Solid Domain | 0.00 | 5.1E-04 | 2.3E-03 | 34.7 9.3E-02 OK| +----------------------+------+---------+---------+------------------+ | E-Pot-Fluid Domain | 0.00 | 2.7E-04 | 2.5E-02 | 6.0E+00 F | | E-Pot-Solid Domain E | 0.00 | 1.4E-17 | 1.0E-16 | 6.0E+00 F | | E-Pot-Solid Domain E | 0.00 | 7.9E-05 | 6.0E-04 | 14.3 6.0E+00 F | +----------------------+------+---------+---------+------------------+ | H-Energy | 0.99 | 2.1E-03 | 5.7E-02 | 2.2E-03 OK| | T-Energy-Solid Domai | 0.87 | 9.9E-05 | 3.5E-03 | 2.2E-03 OK| | T-Energy-Solid Domai | 0.89 | 4.2E-04 | 2.6E-03 | 5.5 2.2E-03 OK| +----------------------+------+---------+---------+------------------+ | K-TurbKE | 0.98 | 9.7E-04 | 1.6E-02 | 5.5 4.7E-03 OK| | E-Diss.K | 0.89 | 1.3E-03 | 6.3E-02 | 10.6 1.2E-03 OK| +----------------------+------+---------+---------+------------------+ ---------------------------------------------------------------------- COEFFICIENT LOOP ITERATION = 2 CPU SECONDS = 5.338E+05 ---------------------------------------------------------------------- | Equation | Rate | RMS Res | Max Res | Linear Solution | +----------------------+------+---------+---------+------------------+ | U-Mom | 1.56 | 3.8E-04 | 1.7E-02 | 1.2E-01 ok| | V-Mom | 1.61 | 3.8E-04 | 1.8E-02 | 1.1E-01 ok| | W-Mom | 0.79 | 4.4E-04 | 1.5E-02 | 7.2E-02 OK| | P-Mass | 1.09 | 7.2E-04 | 1.3E-02 | 16.3 9.8E-02 OK| +----------------------+------+---------+---------+------------------+ | Ax-Mag-Fluid Domain | 0.95 | 1.9E-02 | 7.4E-03 | 2.4E-02 OK| | Ay-Mag-Fluid Domain | 1.00 | 1.7E-02 | 9.5E-03 | 4.5E-02 OK| | Az-Mag-Fluid Domain | 1.21 | 1.0E-01 | 1.2E-02 | 8.8E-02 OK| | Ax-Mag-Solid Domain | 1.27 | 8.3E-03 | 3.0E-03 | 2.4E-02 OK| | Ay-Mag-Solid Domain | 0.95 | 1.3E-02 | 6.3E-03 | 4.5E-02 OK| | Az-Mag-Solid Domain | 0.73 | 1.4E-02 | 4.9E-03 | 8.8E-02 OK| | Ax-Mag-Solid Domain | 1.02 | 8.3E-05 | 6.7E-04 | 2.4E-02 OK| | Ay-Mag-Solid Domain | 0.92 | 7.1E-05 | 6.1E-04 | 4.5E-02 OK| | Az-Mag-Solid Domain | 0.87 | 4.4E-04 | 2.3E-03 | 38.9 8.8E-02 OK| +----------------------+------+---------+---------+------------------+ +--------------------------------------------------------------------+ | ERROR #004100018 has occurred in subroutine FINMES. | | Message: | | Fatal overflow in linear solver. | +--------------------------------------------------------------------+ +--------------------------------------------------------------------+ | An error has occurred in cfx5solve: | | | | The ANSYS CFX solver exited with return code 2. No results file | | has been created. | +--------------------------------------------------------------------+ End of solution stage.

 October 13, 2016, 06:34 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,640 Rep Power: 142 Have you tried the general tips in the FAQ? http://www.cfd-online.com/Wiki/Ansys...do_about_it.3F

 October 13, 2016, 07:58 #3 New Member   Zhen Join Date: Oct 2016 Posts: 4 Rep Power: 9 Yes, but I don't think the link provide useful information in my case. Thank you for the link!