wbinventor/OpenMOC — Issue #67: Keff for c5g7 converges prematurely to ~.91 in some situations
Author: samuelshaner
Created: 2012-03-05 21:47:13+00:00
State: open

This seems to be due to an inflection point in computed Keff values. Below is the an example of premature convergence using a Keff threshold of 1e-5.

>>> ./OpenMOC -g ../xml-sample/Benchmarks/c5g7/geometry.xml -m ../xml-sample/Benchmarks/c5g7/material.xml -na 8 -ts .1 -pf
[ NORMAL ] Starting OpenMOC...
[ NORMAL ] Computing azimuthal angles and track spacings...
[ NORMAL ] Generating track start and end points...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Creating reflective boundary conditions...
[ NORMAL ] Segmenting tracks...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Generating FSR maps...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Making Prefactor array...
[ NORMAL ] Initializing FSRs...
[ NORMAL ] Computing k_eff...
[ NORMAL ] Iteration 0: k_eff = 0.000000
[ NORMAL ] Iteration 1: k_eff = 1.010921
[ NORMAL ] Iteration 2: k_eff = 1.046141
[ NORMAL ] Iteration 3: k_eff = 1.055103
[ NORMAL ] Iteration 4: k_eff = 1.045546
[ NORMAL ] Iteration 5: k_eff = 1.025085
[ NORMAL ] Iteration 6: k_eff = 0.999953
[ NORMAL ] Iteration 7: k_eff = 0.974879
[ NORMAL ] Iteration 8: k_eff = 0.952974
[ NORMAL ] Iteration 9: k_eff = 0.935827
[ NORMAL ] Iteration 10: k_eff = 0.923837
[ NORMAL ] Iteration 11: k_eff = 0.916641
[ NORMAL ] Iteration 12: k_eff = 0.913483
[ NORMAL ] Plotting group 0 flux...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Plotting group 1 flux...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Plotting group 2 flux...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Plotting group 3 flux...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Plotting group 4 flux...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Plotting group 5 flux...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Plotting group 6 flux...
[ NORMAL ] Writing Magick bitmap...
[ NORMAL ] Plotting total flux...
[ NORMAL ] Writing Magick bitmap...
[ RESULT ] k_eff = 0.913492