This option is used when the mass fraction of the fuel component is 1.

This is used when the mass fraction of the oxidizer (usually air) is 1.

Use this parameter when you need to specify the reacted mixture of fuel and oxidizer (for example, in a reacted pilot flame). A value of zero corresponds to 100% oxidizer, and a value of 1 corresponds to 100% fuel.

Used in conjunction with the Mixture Fraction parameter, but additionally you can specify the variance for the "unmixedness" of fuel and oxidizer. By default, the three options above imply zero variance.

This parameter is used to specify the reaction progress variable . corresponds to fresh (unburned) gases, whereas corresponds to completely burned gases. You can select Fresh Gases (), Burned Gases (), or enter a value or expression for the value of .