Computation of Entropy Production in Stratified Flames Based on Chemistry Tabulation and an Eulerian Transported...

Area of Science:

• Combustion Science
• Chemical Engineering
• Thermodynamics

Background:

• Understanding entropy production is key to analyzing exergy losses in combustion systems.
• Stratified premixed flames present complex turbulence-chemistry interactions.
• Accurate modeling of irreversibilities is crucial for efficient combustion system design.

Purpose of the Study:

• To develop and validate a modeling strategy for investigating entropy production in stratified premixed flames.
• To quantify the contributions of different physical and chemical processes to total entropy production.
• To analyze the impact of operating conditions, specifically shear, on entropy generation.

Main Methods:

• Chemistry tabulation strategy for detailed chemical kinetics.
• Large Eddy Simulation (LES) for turbulent flow dynamics.
• Eulerian stochastic field method for turbulence-chemistry interaction modeling.

Main Results:

• Validated chemistry tabulation as a suitable method for calculating irreversibilities.
• Mixing driven by chemical reactions contributes more to entropy production than stratification.
• Increased shear (higher Reynolds number) elevates entropy production from heat, mixing, and viscous dissipation, while reducing the chemical reaction's relative contribution.

Conclusions:

• The proposed modeling approach effectively captures entropy production sources in stratified flames.
• Mixing and chemical reaction dynamics are dominant contributors to entropy generation.
• Operating conditions, particularly shear, significantly influence the balance of entropy production mechanisms.