Large-Scale Turbulent Vortical Structure Inside a Sudden Expansion Cylinder Chamber

Title & Authors
Large-Scale Turbulent Vortical Structure Inside a Sudden Expansion Cylinder Chamber
Seong, Hyeong-Jin; Go, Sang-Cheol;

Abstract
A large eddy simulation(LES) is performed for turbulent flow around a bluff body inside a sudden expansion cylinder chamber, a configuration which resembles a premixed gas turbine combustor. To promote turbulent mixing and to accommodate flame stability, a flame holder is installed inside the combustion chamber. The Smagorinsky model is employed and the calculated Reynolds number is 5,000 based on the bulk velocity and the diameter of the inlet pipe. The simulation code is constructed by using a general coordinate system based on the physical contravariant velocity components. The predicted turbulent statistics are evaluated by comparing them with the laser-doppler velocimetry (LDV) measurement data. The agreement of LES with the experimental data is shown to be satisfactory. Emphasis is placed on the time-dependent evolutions of turbulent vortical structure behind the flame holder. The numerical flow visualizations depict the behavior of large-scale vortices. The turbulent mixing process behind the flame holder is analyzed by visualizing the sectional views of vortical structure.
Keywords
Large Eddy Simulation;Physical Contravariant Velocity Component;Generalized Coordinate;Flame Holder;
Language
Korean
Cited by
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