Effects of reactor design parameters on stability and emissions of vortex flames: A numerical study. (5th June 2019)

• Record Type: Journal Article
• Authors: Davani, Abbasali A.; Amini, Reza; Kashfi, Mehdi
• Is Part Of: Applied thermal engineering. Volume 155(2019)
• Page Start: 584
• Page End: 591
• Publication Date: 2019-06-05
• Subjects: Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2019.04.029
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Effects of reactor design parameters (number of shape of inlets) on stability of combustion investigated numerically. It is found that increasing the number of inlets enhances the flame stability. For same number of inlets, rectangular inlets produce more shear in the flow and hence enhance the efficiency. Emissions are reduced as number of inlets are increased and rectangular slots are used for inlets. Abstract: Effects of design parameters like number and geometry of inlets on flame stability enhancement and emission of axisymmetric vortex chambers (AVCs) have been studied numerically using ANSYS FLUENT. Reynolds Stress Model (RSM) is used to model the flow and a global two-step methane/air reaction with Eddy Dissipation Model (EDM) is used for solving the chemistry-turbulent interactions and closing the chemical source term. Computational results show that when the round jets are used for air inlets, increased number of inlets provide a more stable and rigorous flame by enhancing the forced vortex field in both central and secondary recirculation zones with enhancement reaching a limit as the number of inlets are increased. The performance is significantly better at lean conditions when number of inlets are increased. Increasing number of inlets also led to considerable reduction of CO and NOx emissions. When rectangular slots are used for air inlets instead of jets, stability of the flame is generally increased due to increased shear induced by the geometry of inlets specifically for lean conditions. Efficiency of combustion increased as the number of inlets is increased. Using slot inlets also increases the efficiency and as aspect ratios increased the efficiency increase at lean conditions are enhanced more compare to round jets.