Non-Premixed Combustion: Eddy Dissipation Model

Non-Premixed Combustion, Eddy Dissipation, ANSYS Fluent CFD Training

Description

This project simulates non-premixed combustion inside a combustion chamber using ANSYS Fluent, with fuel and air entering the chamber through two separate boundaries — meeting and mixing only within the chamber itself, consistent with non-premixed combustion behavior. The 2D geometry was designed in Design Modeler and meshed in ANSYS Meshing using a structured mesh optimized for combustion simulation accuracy.

Methodology

The Species Transport model is used to represent the combustion process, applying a single-step methane-air reaction with the volumetric option enabled to capture combustion throughout the chamber. Turbulence-chemistry interaction is handled using the Eddy Dissipation model, which bypasses detailed reaction kinetics and instead accounts for combustion behavior based purely on the effect of turbulent mixing.

The energy equation is enabled to capture temperature changes driven by combustion, with turbulence modeled using the standard k-epsilon model, and solver settings tuned to maintain stability and accuracy throughout the combustion simulation.

Conclusion

The simulation results include contours of temperature, velocity, mass fractions of the various species, and streamlines. The temperature contour shows a clear rise within the chamber, confirming that combustion has taken place.

The streamlines also reveal secondary flow structures forming within the chamber — these secondary flows enhance the mixing between fuel and air, thereby improving the overall combustion process. Together, these results demonstrate how the Eddy Dissipation model captures non-premixed combustion behavior in a way directly applicable to real-world industrial combustion chamber design and analysis.