Validation of Bluff-body Swirling Flame with RANS Turbulent Model and Comparison of the Results with LES Turbulent Model

Abstract

The energy required for technological advancement is primarily derived from hydrocarbon combustion, which is a key topic in thermodynamics. The stability of the flame in hydrocarbon combustion is a critical parameter that impacts both burner design and combustion efficiency. Various methods have been employed in the literature to achieve a stable flame, with swirl flow being one technique that enhances combustion performance in engineering applications. This study focuses on the numerical analysis of the SM1 flame from Sydney swirl flames. Initially, the flow incorporating the two-equation Re-Normalization Group (RNG) k-ε and Shear Stress Transport (SST) k-ω turbulence models, along with the chemical reactions of CH4 combustion using the GRI 3.0 reaction mechanism, was modeled and compared with experimental data. Subsequently, the numerical results obtained from the Shear Stress Transport k-ω turbulence model, which demonstrated the best agreement with experimental data, were compared with results from a numerical analysis in the literature using the Large Eddy Simulation (LES) turbulence model. The predictive capabilities of these two turbulence models, along with their behavior in the flow region, were evaluated. The comparison revealed that for stable flames within the Sydney swirl flame family, the Shear Stress Transport k-ω turbulence model, which provides results in a more efficient manner, is sufficient compared to the computationally expensive Large Eddy Simulation turbulence model. This choice is made possible by utilizing a solution algorithm tailored to the flow characteristics and appropriate boundary conditions.

Keywords

• Swirling flow
• thermodynamics
• non-premixed combustion
• RANS
• LES

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