Time integration failed

[Rahul Kumar]

i am calculating the energy terms. I am using new python 2.7.9

error :Traceback (most recent call last):

  File "F:\Book\VIII Project\new python\adiabatic_flame.py", line 39, in <module>

    f.solve(loglevel=loglevel, refine_grid=True)

  File "onedim.pyx", line 662, in cantera._cantera.Sim1D.solve (cantera/_cantera.cpp:47931)

Exception: 

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

CanteraError thrown by OneDim::timeStep:

Time integration failed.

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i donot know what to do. please tell me

[Ray Speth]

Rahul,

Two changes that I would recommend, which seem to fix the problem, at least in this instance:

1) Set your initial grid to be evenly spaced:

initial_grid = linspace(0, 0.03, 7) # m

2) Keep grid refinement disabled (refine_grid=False) while you're solving with the energy equation disabled.

Regards,

Ray

[Rahul Kumar]

i cannot change the grid, Ray. uneven grid is required 

[Ray Speth]

Rahul,

The final call to 'solve' with refine_grid=True will give you a non-uniform grid that resolves the flame structure appropriately, regardless of initial grid. The initial grid can be chosen arbitrarily, with convergence of the solver on that grid being the only consideration. In this case, a uniform initial grid works while the non-uniform grid you initially supplied does not.

Regards,

Ray