On the concentration fluctuation moments of gas species in turbulent combustion

Abstract

For exploring the influences of chemical reaction on the turbulent fluctuations of gas species concentrations, the reaction source terms in the transport equations for the concentration fluctuation moments are analyzed. It is found that the reaction source terms taken from the equations for the fuel-oxygen, fuel, and oxygen concentration fluctuation moments have a fixed relationship among them. The reaction source terms are not pure production or dissipation terms and they play a redistribution role in these equations. The algebraic concentration moment (ACM)-probability density function (PDF) turbulent combustion model is evaluated. It indicates that the reaction source terms in the modeled transport equations and the resultant explicit algebraic expressions for the concentration fluctuation moments all satisfy the fixed relationship. The reaction source terms serve as the redistribution terms in the explicit expressions for the concentration fluctuation moments.

Keywords:

• Chemical reaction
• concentration fluctuation moment
• turbulence-reaction interactions
• turbulent combustion

Disclosure statement

The authors have no competing interests.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China under Grant Nos. 91541206 and 51376106.