Anybody know what this means???
Non positive diagonal entry detected in ILU method switch to SSOR Preconditioner.
The simulation just stops with no errors or warnings, other than this statement and
Error: Failed in invoking the process: C:\PROGRA~1\Autodesk\SIMULA~1\FRUN03.EXE
Model checks report no errors or warnings. The simulation just ends, with no notifications.
Hi Todd,
Is this a steady fluid flow or another simulation type?
Does the simulation perform some iterations (and maybe even converge?) before you get the message about the SSOR Preconditioner message?
And does the message about failing to run FRUN03 occur in the log file immediately after the preconditioner message, or are their other lines of text in between the two?
I think the preconditioner is a way to guess at the solution to seed the iterative solver. So switching from one to the other is not a concern.
I believe FRUN03 is the fluid flow processor, which I presume was running to get to the preconditioner message. I'm not sure whether it restarts after the preconditioner message and may have some type of timing issue or if it is something else. So please try
a) Start My Computer/Windows Explorer
b) Browse to the folder containing the model (the location of the .FEM file).
c) browse into the model-name.ds_data folder. This is where you will find the the folders for the design scenarios.
d) Hold the shift key and right-click on the design scenario folder for the fluid model, and choose "open command window here".
e) In the command window, type
C:\PROGRA~1\Autodesk\SIMULA~1\FRUN03.EXE DS -run
where
Assuming it fails just like before, scroll through the command window to look for any additional messages.
Hi John,
Thank you for the reply. I'm running a coupled thermal/fluid flow steady state analysis.
The log files typical of what I receive are documented in a previous thread:
I've tried running the simulations uncoupled, which would be fine for my application, but I don't trust the results. Please see this thread for an example of the strange results:
I was able to get the simulation to run without giving me the non-positive diagonal entry error by switching the preconditioner from ILU to SSOR (I think!). However, this wasn't straightforward. In the Thermal Analysis settings, it's straightforward to set the preconditioner to SSOR as shown in the following image:
If you might remember from a previous thread, for some reason Simulation wants to use the Sparse solver instead of the Iterative. If I don't change it manually, it will give me an "AlgSolve.exe is not a valid application" error, as we discussed here:
In the Fluid Analysis paramters I also changed both the Velocity and Pressure Solver Controls to BCSLIB-EXT, as follows:
But there was one other step that was a bit more difficult... When the solver is set to Sparse, the preconditioner option is not available:
What I had to do to get the simulation to run was to set the solver to Iterative, then change the preconditioner to SSOR, then change it back to sparse. (I've been fighting with this for weeks, and right now, I don't remember why I couldn't leave it on iterative.)
Like I said, a lot of this has been trial and error, so I'm not 100% sure what finally worked. (I think it was the final change of preconditioner. Even when everything was set to sparse, I was still getting the ILU/SSOR error.)
So that was a minor success.
However, the first few of my load cases ran, and then failed on the 5th load case. Here's the log file:
Autodesk (R) Simulation Steady Coupled Fluid Flow and Thermal Analyses Version 2013.02-WIN 02-Oct-2012 Copyright (c) 2012, Autodesk, Inc. All rights reserved. DATE: October 16, 2012 TIME: 10:11:24 AM INPUT MODELS: ...inth attempt\choroidal absorption.ds_data\1\ds **** **** Iteration starts for velocity and temperature updates **** For Buoyancy Force :: LC No. = 2 Total No. of Intvs = 1 ------------------------------------------------------------------------ Current No. Load Turbulent Max. No. Convergence Tolerance Intv No. Steps Multiplier Model Iters (Temp.) (Vel.) 1 8 1.00e+000 off 500 1.00e-003 1.00e-003 ------------------------------------------------------------------------ Intv No. Step No. Iter. No. Euc. Norm (Vel.) Euc. Norm (Temp.) 1 1 1 Rlx = 0.200 Rlx = 0.200 1 1 2 3.338e-002 4.687e+000 1 1 3 7.336e-003 3.752e+000 1 1 4 5.781e-003 3.003e+000 1 1 5 4.585e-003 2.403e+000 1 1 6 3.666e-003 1.923e+000 1 1 7 2.961e-003 1.539e+000 1 1 8 2.422e-003 1.231e+000 1 1 9 2.009e-003 9.850e-001 1 1 10 1.692e-003 7.882e-001 1 1 11 1.448e-003 6.306e-001 1 1 12 1.258e-003 5.046e-001 1 1 13 1.109e-003 4.037e-001 1 1 14 9.903e-004 3.230e-001 1 1 15 8.936e-004 2.584e-001 1 1 16 8.134e-004 2.067e-001 1 1 17 7.456e-004 1.654e-001 1 1 18 6.871e-004 1.323e-001 1 1 19 6.360e-004 1.059e-001 1 1 20 5.906e-004 8.470e-002 1 1 21 5.499e-004 6.777e-002 1 1 22 5.130e-004 5.422e-002 1 1 23 4.794e-004 4.337e-002 1 1 24 4.487e-004 3.470e-002 1 1 25 4.204e-004 2.776e-002 1 1 26 3.942e-004 2.221e-002 1 1 27 3.700e-004 1.777e-002 1 1 28 3.476e-004 1.421e-002 1 1 29 3.267e-004 1.137e-002 1 1 30 3.072e-004 9.097e-003 1 1 31 2.891e-004 7.278e-003 1 1 32 2.722e-004 5.822e-003 1 1 33 2.563e-004 4.658e-003 1 1 34 2.415e-004 3.726e-003 1 1 35 2.276e-004 2.981e-003 1 1 36 2.146e-004 2.385e-003 1 1 37 2.025e-004 1.908e-003 1 1 38 1.910e-004 1.526e-003 1 1 39 1.803e-004 1.221e-003 1 1 40 1.702e-004 9.765e-004 >> Current elapsed time = 218.333 minutes For Buoyancy Force :: LC No. = 2 Total No. of Intvs = 1 ------------------------------------------------------------------------ Current No. Load Turbulent Max. No. Convergence Tolerance Intv No. Steps Multiplier Model Iters (Temp.) (Vel.) 1 8 1.00e+000 off 500 1.00e-003 1.00e-003 ------------------------------------------------------------------------ Intv No. Step No. Iter. No. Euc. Norm (Vel.) Euc. Norm (Temp.) 1 2 1 Rlx = 0.200 Rlx = 0.200 1 2 2 1.282e-002 6.715e-003 1 2 3 1.015e-002 1.126e-002 1 2 4 8.034e-003 1.391e-002 1 2 5 6.363e-003 1.517e-002 1 2 6 5.041e-003 1.545e-002 1 2 7 3.994e-003 1.507e-002 1 2 8 3.166e-003 1.427e-002 1 2 9 2.511e-003 1.321e-002 1 2 10 1.991e-003 1.203e-002 1 2 11 1.580e-003 1.080e-002 1 2 12 1.255e-003 9.589e-003 1 2 13 9.971e-004 8.439e-003 1 2 14 7.929e-004 7.369e-003 1 2 15 6.313e-004 6.392e-003 1 2 16 5.032e-004 5.514e-003 1 2 17 4.018e-004 4.732e-003 1 2 18 3.216e-004 4.044e-003 1 2 19 2.581e-004 3.442e-003 1 2 20 2.079e-004 2.920e-003 1 2 21 1.683e-004 2.469e-003 1 2 22 1.369e-004 2.082e-003 1 2 23 1.122e-004 1.751e-003 1 2 24 9.265e-005 1.470e-003 1 2 25 7.722e-005 1.231e-003 1 2 26 6.503e-005 1.028e-003 1 2 27 5.536e-005 8.580e-004 >> Current elapsed time = 367.250 minutes For Buoyancy Force :: LC No. = 2 Total No. of Intvs = 1 ------------------------------------------------------------------------ Current No. Load Turbulent Max. No. Convergence Tolerance Intv No. Steps Multiplier Model Iters (Temp.) (Vel.) 1 8 1.00e+000 off 500 1.00e-003 1.00e-003 ------------------------------------------------------------------------ Intv No. Step No. Iter. No. Euc. Norm (Vel.) Euc. Norm (Temp.) 1 3 1 Rlx = 0.200 Rlx = 0.200 1 3 2 1.502e-002 9.643e-003 1 3 3 1.189e-002 1.533e-002 1 3 4 9.419e-003 1.862e-002 1 3 5 7.463e-003 2.015e-002 1 3 6 5.915e-003 2.045e-002 1 3 7 4.690e-003 1.991e-002 1 3 8 3.721e-003 1.883e-002 1 3 9 2.954e-003 1.742e-002 1 3 10 2.347e-003 1.585e-002 1 3 11 1.866e-003 1.424e-002 1 3 12 1.486e-003 1.264e-002 1 3 13 1.185e-003 1.113e-002 1 3 14 9.477e-004 9.718e-003 1 3 15 7.598e-004 8.432e-003 1 3 16 6.116e-004 7.274e-003 1 3 17 4.946e-004 6.245e-003 1 3 18 4.026e-004 5.337e-003 1 3 19 3.302e-004 4.544e-003 1 3 20 2.734e-004 3.855e-003 1 3 21 2.288e-004 3.261e-003 1 3 22 1.939e-004 2.750e-003 1 3 23 1.665e-004 2.313e-003 1 3 24 1.449e-004 1.942e-003 1 3 25 1.277e-004 1.626e-003 1 3 26 1.139e-004 1.359e-003 1 3 27 1.027e-004 1.134e-003 1 3 28 9.341e-005 9.446e-004 >> Current elapsed time = 524.333 minutes For Buoyancy Force :: LC No. = 2 Total No. of Intvs = 1 ------------------------------------------------------------------------ Current No. Load Turbulent Max. No. Convergence Tolerance Intv No. Steps Multiplier Model Iters (Temp.) (Vel.) 1 8 1.00e+000 off 500 1.00e-003 1.00e-003 ------------------------------------------------------------------------ Intv No. Step No. Iter. No. Euc. Norm (Vel.) Euc. Norm (Temp.) 1 4 1 Rlx = 0.200 Rlx = 0.200 1 4 2 1.807e-002 1.266e-002 1 4 3 1.431e-002 2.029e-002 1 4 4 1.134e-002 2.474e-002 1 4 5 8.986e-003 2.687e-002 1 4 6 7.123e-003 2.735e-002 1 4 7 5.649e-003 2.669e-002 1 4 8 4.483e-003 2.529e-002 1 4 9 3.560e-003 2.345e-002 1 4 10 2.829e-003 2.137e-002 1 4 11 2.251e-003 1.922e-002 1 4 12 1.794e-003 1.709e-002 1 4 13 1.433e-003 1.506e-002 1 4 14 1.147e-003 1.317e-002 1 4 15 9.214e-004 1.144e-002 1 4 16 7.436e-004 9.879e-003 1 4 17 6.035e-004 8.488e-003 1 4 18 4.933e-004 7.261e-003 1 4 19 4.069e-004 6.186e-003 1 4 20 3.392e-004 5.252e-003 1 4 21 2.861e-004 4.445e-003 1 4 22 2.446e-004 3.751e-003 1 4 23 2.119e-004 3.157e-003 1 4 24 1.861e-004 2.651e-003 1 4 25 1.655e-004 2.221e-003 1 4 26 1.489e-004 1.857e-003 1 4 27 1.353e-004 1.550e-003 1 4 28 1.239e-004 1.292e-003 1 4 29 1.142e-004 1.075e-003 1 4 30 1.058e-004 8.926e-004 >> Current elapsed time = 687.317 minutes For Buoyancy Force :: LC No. = 2 Total No. of Intvs = 1 ------------------------------------------------------------------------ Current No. Load Turbulent Max. No. Convergence Tolerance Intv No. Steps Multiplier Model Iters (Temp.) (Vel.) 1 8 1.00e+000 off 500 1.00e-003 1.00e-003 ------------------------------------------------------------------------ Intv No. Step No. Iter. No. Euc. Norm (Vel.) Euc. Norm (Temp.) 1 5 1 Rlx = 0.200 Rlx = 0.200 1 5 2 2.269e-002 1.725e-002 1 5 3 1.797e-002 2.796e-002 1 5 4 1.424e-002 3.430e-002 1 5 5 1.128e-002 3.741e-002 1 5 6 8.946e-003 3.822e-002 1 5 7 7.096e-003 3.742e-002 1 5 8 5.631e-003 3.556e-002 1 5 9 4.472e-003 3.305e-002 1 5 10 3.554e-003 3.020e-002 1 5 11 2.828e-003 2.721e-002 1 5 12 2.254e-003 2.425e-002 1 5 13 1.800e-003 2.141e-002 1 5 14 1.441e-003 1.875e-002 1 5 15 1.158e-003 1.631e-002 1 5 16 9.343e-004 1.410e-002 **** Error: Temperature update failed. Quit.
This is similar to a problem I previously reported in this thread:
For whatever reason, it appears that Simulation only likes running a few load cases at a time. As documented in the previous thread, if I change the order of the load cases, I bet the failure has nothing to do with the load case itself and I'll be able to get results.
I don't believe this is a resource problem, as I have a ton of hard disk space, 16 gigs of RAM, and 2 quad-core processors, and I'm running the 64 bit versions of Windows 7 and Simulation Multi-Physics.
Thank you, John, for the command line info for FRUN03; that may help me debug in the future.
Are the command line inputs for all of the FRUNs documented somewhere? Also, how about the log files? The report tab doesn't say which Log is which, so I've hunted through the output files and found them, but I'm not sure which ds.xxx file corresponds to which solver.
Thank you!!
Todd