Spark-ignition Engine Zonal Model for Knock Assessment

[Saravana Kumar Lakshmanan]

Hello Peers,

I am very much new to Cantera. My objective is to find auto ignition timing/knocking crank angle for NA-MPI gasoline engine. Currently, I have used Chemkin (particularly spark ignition engine zonal model). Is there any similar model available in Cantera?

Kindly help me on this. Even after long search in this group and general google search, I am not able to find anything relevant.

[Bryan Weber]

Hi,

If you haven't found anything by searching, then it is unlikely to have already been implemented. However, Cantera is probably flexible enough for you to be able to accomplish your goals with a little bit of modeling work on your end. If you can write down the ODE/DAE system that represents your problem of interest, you can probably solve it based on some of the examples on our website (https://cantera.org/examples).

That said, it's really hard to provide specific advice without any code or something to go by. Once you've got something started, please feel free to ask any questions about errors that you're getting!

Best,

Bryan

[Saravana Kumar Lakshmanan]

Hello all,

Since there is no ready made  model available in Cantera which is similar to SI engine knock assessment Chemkin model, I have started building it on own by breaking down in to smaller tasks. I have approached this problem  as given below:

1. Creation of single zone HCCI Cantera code --> Basically to gain confidence on the engine like implementation (Instantaneous volume change to reactor like engine with adiabatic conditions to reactor)
2. Extended the code to simplified heat transfer equation and compared with Chemkin results.
3. Further, incorporated Woschni heat transfer equation to the code and compared with Chemkin results.

Basically,  all these steps are done to gain confidence on the Cantera script which will behave as engine and heat transfer conditions at the engine walls.
After completing these things, I have explored the Cantera tutorials which handles two zone and mass exchanges between them.
1.piston.py - https://cantera.org/examples/python/reactors/piston.py.html
2.reactor2.py - https://cantera.org/examples/python/reactors/reactor2.py.html

3.periodic_cstr.py - https://cantera.org/examples/python/reactors/periodic_cstr.py.html
4.fuel_injection.py - https://cantera.org/examples/python/reactors/fuel_injection.py.html

Though these tutorials provided some insight about the two reactor handling and mass exchange in the reactors, I am not able to model the two zone/reactor with the following requirements.
These requirements are taken from Chemkin manual. I would like to have support from the Cantera users to implement these equations.
I have attached the developed script (till this point) and the exact equations below.

Regards,
Saravana Kumar Lakshmanan.

[Ingmar Schoegl]

Hi Saravana,

This is an interesting problem, and not a trivial one to implement. At the moment, Cantera only ships with a very simplistic engine model example. As you point out, the two-zone model has the mass exchange between the two reactors; likewise, the cylinder volume needs to be split into zones. One brand-new Cantera capability are extensible reactors, which allow you to extend the governing equations in Python, and may be something worth pursuing for this problem. I'm definitely curious about a solution to your problem as it would be terrific application to have.

-ingmar-

[Saravana Kumar Lakshmanan]

Hi  Ingmar Schoegl,

Thanks for your valuable comment about this problem. I will try to look in to "extensible reactors" Cantera documentation.

Regards,

Saravana Kumar Lakshmanan.

[Saravana Kumar Lakshmanan]

Hello all,

Based on Ingmar reply, I have started exploring "Extensible reactor" documentation. I can see only 1 example script in the documentation page. If anyone working with extensible reactor, especially on "ExtensibleIdealGasReactor", Kindly share me the sample script of modifying all 4 governing equations of idealgasreactor?

Regards,

Saravana Kumar Lakshmanan.

[Aaqif Ahmed]

Hey Saravana,

I am working on a multi zone engine model, and would like to know if you've a solution to the problem. I am trying to figure out the complications of mass transfer between zones and the division of cylinder into multi zones and modelling that with cantera's reactors. 

Aaqif