Reaction Path Analysis

[marm....@iitgn.ac.in]

Dear All,

I have been trying to run the reaction path analysis code for some time now. However the code keeps throwing this error. 

"/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../x86_64-linux-gnu/crt1.0: In function '_start':

(.text+0x20): undefined reference to 'main'

collect2: ld returned 1 exit status"

Any help will be appreciated.

Regards.

Marm Dixit

Junior Research Fellow

IIT Gandhinagar

[Ray Speth]

Marm,

A lot more detail is required to diagnose this error. From what you posted, it's not even clear that this error has anything to do with Cantera. What are you doing that produces the error? What version of Cantera are you using, on what operating system, and how did you install it?

Regards,

Ray

[marm....@iitgn.ac.in]

Ray, 

Thanks for the response.I believe the error was caused by the absence of the main function in the code. Got that to work. 

Now, I have generated these ps files for a case of H2/O2 combustion. What I do not get is what are the values on the arrows when multiplied with the scale. Someone wrote it as the forward rate of progress, while at some places it is mentioned as the flux going from one species to the other. Any ideas on what physical quantity that it signifies, and what are the units. 

Thanks for the response.

Regards.

Marm

[Ray Speth]

Marm,

The values are the (net) rates at which each species is formed from another species, measured in kmol/m^3/s, i.e. the same as the reaction rates of progress. It is not necessarily the same as the forward rate of progress for any specific reaction, since a single A->B species pair may be the sum of multiple reactions occurring in either the forward or reverse direction. It can be thought of abstractly as a flux if you consider each species to be in a reservoir which can be replenished or depleted by reactions.

Regards,

Ray

[marm....@iitgn.ac.in]

Thanks for that. Just a thought, so for surface reactions if I am plotting the reaction paths, the units will come to be kmol/m2/s, right?

[Steven DeCaluwe]

Yes, that is correct. 

Cheers,

Steven

Sent from my iPhone

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[marm....@iitgn.ac.in]

Awesome. Thanks a lot!

Cheers.

Marm

[Alan Kong]

Hi Marm,

just a quick trivial question, how did u print the time at which the reaction path diagram is taken on the .dot files?

Cheers

Alan

[marm....@iitgn.ac.in]

I actually did not end up printing the times at which the paths are drawn. But had written the code so that it ended up giving me the RPA for the final configuration of the reactor, by which I knew what 'time step' it was. You will also find here a little idea as to how to incorporate RPAs at different timesteps.

That probably does not help a lot, but that's what I did. 

Cheers.
Marm

[Marcus Day]

BTW, the units Ray suggested here are incorrect.  The Path diagram for element E shows molar rate that atoms E are transferred per sec per unit volume between the two species at the ends of the arrow.  If for example a reaction #n is A+B -> 2C+D, and proceeds with a forward rate of F and a reverse rate of R, and each molecule of A contains 3 E atoms, B contains no E's, each C contains 1 E and each D contains 1 E, then the contribution of #n to the flow of E's from A to C is 2(F-R), and from A to D is (F-R).  There may be several reactions that transfer E atoms from A to C and the total flux will be the approapriately weighted sum of the net fluxes of all of them.

Dave and I talked a lot about this and were working simultaneously on separate codes to do this same operation.  I have a similar tool for this with a different design spec. Rather than having dot place the nodes automatically, I developed a drawing tool to place them as you want.  The downside is that it involves user intervention, the upside is that you can make a set of plots under different conditions and compare them more easily if the nodes are in the same location.  You also may wish to generate the plot with data generated in different ways (integrated over a flame or flamelet, or other more generic conditioning strategies in multidimensional flows).  Dave wrapped his implementation pretty tightly in the bowels of the code so it's tricky to do such conditioned integrals.

I haven't maintained my code, but it is available as a separate tool at https://ccse.lbl.gov/Research/Combustion/README_chemPathTool.htm

If you find it, and find it useful, please let me know.

-Marc

[Hugo Cortes]

Dear Marc,

We have been working on Cantera's Reaction Path Diagram, but until now haven't got the results we were looking for. Your solution seems to tailor our needs and I've been trying to install and run the Chem Path Tool.

I've insallled Pmw but haven't got the Chem Path Tool running. My question regarding the Installation is: after untaring the ChemPathTool-1.1 file, should I run python command window and install? Or just copy the files to the same Directory and then Import ChemPathTool in the python code?

I tried also  the Installation with PIP, got this error message:

"Could not find a Version that satisfies the requirement ChemPathTool:

No matching Distribution found for ChemPathTool "

We are running Python 3.4, should that be a Problem?

Thanks in advance, we really want to have a try on the ChemPathTool

Best Regards

Hugo Cortes