Numerical Analysis of the Combustion Dynamics of Passively Controlled Jets Issuing from Polygonal Nozzles

In the present work, combustion of vitiated hydrogen jets issuing from differently shaped nozzles is modelled using LES method. We investigate impact nozzle cross-sectional geometries (circular, square, triangular, hexagonal and hexagram) jet Reynolds numbers (Re= 18,000, 20,000 23,600) on flame lift-off height, its structure, locations temperature maxima species distributions. The triangular yields highest mixing rate therefore fastest decay axial velocity growth average along axis. It was found that for largest Re, zone intense reaction occur in distinct regions, while lower these regions combine into an indistinguishable zone. Finally, it shown height flames mean field are non-linearly correlated with Re strongly dependent shape.