Large-eddy simulation of turbulent autoigniting hydrogen lifted jet flame with a multi-regime flamelet approach |
| |
Affiliation: | 1. Institute for Simulation of reactive Thermo-Fluid Systems, TU Darmstadt, Darmstadt 64287, Germany;2. School of Mechanical and Manufacturing Engineering, The University of New South Wales, NSW 2052 Australia;3. Institute for Energy and Power Plant Technology, TU Darmstadt, Darmstadt 64287, Germany;4. Sandia National Laboratories, Livermore, CA 94550, USA;1. Department of Mechanical Engineering and Science, Kyoto University, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan;2. State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026, China;3. Numerical Flow Designing Ltd., Higashigotanda, 1-10-10, Shinagawa City, Tokyo 141-0022, Japan;4. School of Aerospace Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia |
| |
Abstract: | In this work, the combustion model is focused on to describe a multitude of reaction regimes that are deemed to affect the flame stabilization. For this purpose, an efficient flame indicator is formulated to differentiate the differing flame structures and make use of flamelet chemistry that accounts for autoignition and multi-regime reactions. The large eddy simulation with this methodology is carried out to compute a turbulent lifted hydrogen-nitrogen flame in vitiated coflow. The canonical flame models of a laminar premixed flame and an unsteady counterflowing flame have been used to simulate the flamelet structure at different regimes. Present model improves the prediction of mean and rms profiles for temperature and species mass fraction in the comparison with experiments and a reference simulation, adopting the single-regime flamelet. The computed results also demarcate the formation of a triple flame structure at the flame base, where combustion develops into the premixed reaction that extends to the fuel-lean and rich branches. The counterflow mixing mode with autoignition is identified as the major mechanism for stabilization and is responsible for the propagating premixed zone above the liftoff height. The developed multi-regime flamelet approach properly accounts for the interactive different modes of burning. |
| |
Keywords: | Lifted hydrogen flame LES Triple flame Autoignition Multi-regime flamelet |
本文献已被 ScienceDirect 等数据库收录! |
|