Non-premixed Combustion in Swirl Burner CFD Simulation, ANSYS Fluent Training

Non-premixed combustion in swirl burners is a fascinating combination of fluid dynamics and combustion science. These burners have unusual flame characteristics because fuel and oxidizer are not premixed before combustion. The flow gains angular velocity from the swirl, which improves mixing and combustion. This whirling motion forms a core combustion zone surrounded by partly reacted gasses. This time, we are going to simulate the Non-premixed combustion inside a Swirl burner. For higher credibility, the reference paper entitled “Experimental and numerical investigation of turbulent isothermal and reacting flows in a non-premixed swirl burner” is selected.

Simulation Process

The 3D geometry consists of two separate zones that are connected by a swirler. In the entrance zone, methane and air are mixing and there isn`t any reaction. Passing through the swirler makes it ready to react. Overall, 7039181 tetrahedron elements are needed to have appropriate grid.

The volumetric reactions are modeled using Species Transport model. To model turbulent combustion, the Eddy Dissipation Model (EDM) of Magnussen and Hjertager is used.

Post-processing

Contour investigations of the simulated non-premixed combustion within the swirl burner give significant insights into flow and temperature distribution. The contours depict the evolution of the combustion process, with discrete zones of high temperature and species concentrations resulting from the burner. As the methane combines with the oxidizer, temperatures rise to 2283K, indicating strong burning. The contours also indicate swirl-induced mixing, which demonstrates the effective blending of fuel and oxidizer inside the combustion zone. These findings demonstrate the importance of the swirl burner design in promoting complete combustion while also giving useful data for optimizing burner performance and increasing efficiency in practical applications.