Counterflow NP flame (with added plasma species)

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Hello,

I'm using the Counterflow NP flame from Matlab with added plasma 
species/reactions. I created a new .cti file as an input file which is a 
modified version of the GRI mechanism. The new mechanism has GRI-3.0 mechanism 
with added plasma species viz. electrons and ions and chemiionization 
reactions. But it seems that cantera is not compiling those reactions and so 
its not measuring the new species mass fractions. If I try to plot the electron 
profile it is giving absurd mass fraction something which is not possible like 
negative mass fraction and something of the order of 10E-26 (Just to be sure 
that the charged species is not giving any problems I also tried some reactions 
with Ozone-O3 and its still not measuring O3 concentration). I am attaching the 
input file as well as the modified Counterflow NP flame model.

Thank you, I appreciate any help which I really need.
Parth Shah

Original issue reported on code.google.com by shah13pa...@gmail.com on 13 Sep 2012 at 9:18

Attachments:

• diffflame.m
• gri_july29.cti

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(1) The Matlab script you gave doesn't use the mechanism you specified.

After fixing that problem...

(3) Cantera is clearly calculating rates for the reactions you added. For 
example:

    set(gas, 'T',600, 'P', oneatm, 'X', ones(1, nSpecies(gas)));
    C = creationRates(gas);
    C(54:end)

    ans =

       1.0e+08 *

        0.0062
        0.0011
        0.0002
        0.0020
        0.0020
        0.0036
        0.0000
        0.0028
        0.3767
        0.0004
        0.0000
        0.0000
        2.0557

(4) In the Matlab script, the absolute tolerance is set at 1e-20. This means 
that you should consider any quantity whose absolute value is less than this to 
be numerically equivalent to zero. This includes negative mass fractions.

(5) You can use the solution obtained from the Matlab script to compute the 
creation / destruction rates for the species. You will see that all of the 
rates associated with the added species are about 6 orders of magnitude lower 
than those for the species that are part of the original mechanism. To me, this 
suggests that you have a problem with the units of your rate constants.

None of this indicates any problems with Cantera. If you need help using 
Cantera, please seek it from the Cantera User's group 
(https://groups.google.com/forum/?fromgroups#!forum/cantera-users) and only 
report issues here when you have some evidence that you have found a bug in 
Cantera.

Original comment by yarmond on 14 Sep 2012 at 3:34

• Changed state: Invalid
• Added labels: Type-Other
• Removed labels: Type-Defect

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1) I actually did specify the right input (mechanism) file while I was actually 
running it, here by mistake I have the wrong file. Thanks for pointing that out.

2) I actually did post the problem on the Cantera Groups but none of them 
responded.

Thank you very much! You're the best!

Original comment by shah13pa...@gmail.com on 14 Sep 2012 at 6:24