[xbw]

Hello
I want to slow down the flame spreading speed through weakening the turbulence intensity , but i don't know how to modulate parameters to weaken the turbulence intensity.The turbulence model that i used is RNG k-ε model,could everyone please help me?

[Blanco]

What combustion model are you using?

[xbw]

Originally Posted by Blanco

What combustion model are you using?

SAGE model

[Blanco]

I suppose you're doing RANS.

In that case, assuming you don't want to "tune" the mechanism you're using, I would suggest to change turbulence kinetic energy tke through the mapping:
- start the simulation before spark timing with a mapping, and scale your tke as desired.

However, the results you'll get will be just representative of the artificially modified tke...if you want to "naturally" obtain a lower/higher tke w/o forcing anything you have to check carefully:
- grid size
- turbulence model
- wall y+ values

[SamWijey]

You can change the turbulent schmidt (Sc) number to change turbulent diffusion. Increasing the Sc number lowers the turbulent diffusion. This will in turn reduce burn rates. You can find Sc number in inputs.in.