Ko, Sang Cheol; Sung, Hyung Jin Large-scale turbulent vortical structures inside a sudden expansion cylinder chamber. (English) Zbl 1113.76359 Flow Turbul. Combust. 68, No. 3, 269-287 (2002). Summary: 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 and the Lagrangian dynamic subgrid-scale model are employed and tested. The calculated Reynolds number is 5,000 based on the bulk velocity and the diameter of 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 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 structures behind the flame holder. The numerical flow visualizations depict the behavior of large-scale vortices. The turbulent behavior behind the flame holder is analyzed by visualizing the sectional views of vortical structure. MSC: 76F65 Direct numerical and large eddy simulation of turbulence 80A25 Combustion Keywords:flame holder; generalized coordinate; large eddy stimulation; large-scale vortical structure; physical contravariant velocity component PDFBibTeX XMLCite \textit{S. C. Ko} and \textit{H. J. Sung}, Flow Turbul. Combust. 68, No. 3, 269--287 (2002; Zbl 1113.76359) Full Text: DOI