Combustion: Vortex Combustion Chamber

Vortex Combustion Chamber Simulation in ANSYS Fluent

Introduction

This project simulates the combustion reaction occurring inside a vortex combustion chamber using ANSYS Fluent. Combustion is a chemical process between a combustible material and an oxidizing agent, resulting in the release of heat and the transformation of raw materials, typically accompanied by light in the form of a flame or glow. While combustion is fundamentally a form of oxidation reaction, its rapid reaction rate, substantial heat release, and associated temperature rise and flame formation place it in a distinct category of chemical processes. The vortex combustion chamber represents a new generation of liquid-fuel internal combustion engine design, in which a specific injector arrangement generates a swirling vortex flow. This vortex enhances cooling and improves mixing of the propulsion components within the chamber, enabling complete combustion to be achieved in a smaller chamber volume.

Geometry and Mesh

The combustion chamber geometry was designed and meshed within GAMBIT, using an unstructured mesh totaling 379,535 cells.

Methodology

The combustion process was analyzed using the species transport model, with a mixture of air and methane serving as the fuel. The Eddy-Dissipation method was employed to capture the chemical-turbulent interaction of the combustion reactants, and the NOx prediction model was activated, using the temperature method for the turbulence-chemistry interaction mode. The ideal gas equation was used to account for density variations resulting from temperature changes within the chamber.

Results and Conclusion

Contours of velocity, pressure, temperature, and species mass fraction were generated in both 3D and 2D, clearly capturing the formation of the combustion flame and the resulting temperature distribution within the chamber. Velocity vectors reveal a high degree of flow turbulence throughout the domain, and the overall contour results confirm that the combustion chamber's performance has been accurately captured by the simulation.