Learning Forum

[ss00321]

The SI model uses the flame-sheet approximation for fuel combustion, which assumes complete combustion occurs instantaneously.

I would like to disable this option to use a detailed kinetic in the SI Simulator, similar to what is done in other reactor models, such as Batch or PFR.

However, I cannot find options such as “Burned Gas Chemistry: Finite-Rate”, “Enable Chemistry in Burned Zone”, or “Post-Flame Kinetics” to prevent the burned zone from using equilibrium.

Is it necessary to modify the model through programming to achieve this?

If so, could someone please show me how to implement it?

[jcooper]

Hi:

The Chemkin models are designed for simplified analyses of more complex cases. The premise of the zonal SR model is two distinct zones, an unburned zone and a burned zone, separated by a infinitely thin flame region. This is adequate for many of the combustion processes in SI engines.  Enabling detailed chemistry would "break" this assumption, because it would create a much thicker intermediate zone and invalidate the other assumptions inherent in the model. 

To model detailed chemistry in the same framework, I would consider creating a 3d model and using Fluent or Forte.

Regards,

Judy