Ignition delay
 

Good morning everyone,
I am dealing with a methane engine, homogeneous fuel distribution, simulating the ignition and combustion phase (630 deg - 760 deg). Mixture is poor, lambda = 1.5529. I am trying to create a suitable model, so trying pressure and apparent heat release to match with experimental data. My problem is that the pressure (and consequently AHR) raises too late, and reaches low peak values with respect to experimental case.
I think the problem is in the Laminar flame speed.


My questions are:

1. is it correct to use Gülder correlation in case of methane with lambda = 1.5529? Should I change any coefficient of the model? Can the problem be caused by settings in ISSIM ignition model?
2. is there a way to plot laminar flame speed as a function of crank angle in STAR-CD?


My setup:
ECFM-3Z (ISSIM ignition with 0.1 J energy)
CH4 fuel premixed
Adiabatic BC for the electrodes


Attachment 71010
Attachment 71011


Thank you in advance, Salvo

Have you in the meantime resolved the issue you describe here?