Flow Regimes and Combustion Characteristics of Swirling Turbulent Flames in Furnaces

Abstract

The present paper is study of the effect of swirl number on combustion characteristics such as temperature, velocity, gas concentrations in a natural gas diffusion flame. Numerical simulations carried out using the commercial computational fluid dynamics (CFD) code, Ansys 14.0 by choosing appropriate model parameters. The combustion reaction scheme in the flame region was modeled using flamelet model. A standard k-e turbulence model for turbulent closure. In order to investigate the swirling effect on the combustion characteristics, six different swirl numbers including 0; 0.1; 0.2; 0.3; 0.4 and 0.5 are used in the study. Numerical results are validated and compared with published experimental and simulation results. A good consistency is found between the present results and those published measurement and simulation results in the available literature. The results shown that the combustion characteristics such as the flame temperature, the gas concentrations including CO2, H2O, and CH4 are strongly affected by the swirl number. Depending on the degree of swirl, the fluid dynamics behaviour of natural gas diffusion flame including axial velocity distribution, recirculation zone also strongly affected.