Check the CCL for your combustion calculation. For each domain, the combustion model section might read as follows:

In dom1:

FLUID MODELS:

COMBUSTION MODEL:

Eddy Dissipation Model Coefficient B = 0.5

Extinction Temperature = 5000[K]*(1-fcomb1)+700[K]*fcomb1

Option = Eddy Dissipation

END

In dom2:

FLUID MODELS:

COMBUSTION MODEL:

Eddy Dissipation Model Coefficient B = 0.5

Extinction Temperature = 5000[K]*(1-fcomb2)+700[K]*fcomb2

Option = Eddy Dissipation

END

In dom3:

FLUID MODELS:COMBUSTION MODEL:

Eddy Dissipation Model Coefficient B = 0.5

Extinction Temperature = 5000[K]*(1-fcomb3)+700[K]*fcomb3

Option = Eddy Dissipation

END

Finally, in sparks:

FLUID MODELS:

COMBUSTION MODEL:

Eddy Dissipation Model Coefficient B = 0.5

Extinction Temperature = 5000[K]*(1-fcombs)+700[K]*fcombs

Option = Eddy Dissipation

END

The expression fcombs = fcomb1 + fcomb2 + fcomb3 should be added to the CEL section.