LES modelling of turbulent non-premixed jet flames with correlated dynamic adaptive chemistry |
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| Authors: | Zaigang Liu Wenhu Han Yiguang Ju |
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| Institution: | 1. Key Laboratory of Light-Duty Gas-Turbine, Institute of Engineering Thermophysics, Chinese Academy of Sciences , Beijing, PR China;2. School of Engineering Sciences, University of Chinese Academy of Sciences , Beijing, PR China;3. Key Laboratory of Light-Duty Gas-Turbine, Institute of Engineering Thermophysics, Chinese Academy of Sciences , Beijing, PR China;4. Department of Mechanical and Aerospace Engineering, Princeton University , Princeton, New Jesery, USA |
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| Abstract: | Large eddy simulations (LES) for turbulent flames with detailed kinetic mechanisms have received growing interest. However, a direct implementation of detailed kinetic mechanisms in LES modelling of turbulent combustion remains a challenge due to the requirement of huge computational resources. An on-the-fly mechanism reduction method named correlated dynamic adaptive chemistry (CoDAC) is proposed to overcome this issue. A LES was conducted for Sandia Flame-D, with the reaction mechanism of GRI-Mech 3.0 consisting of 53 species and 325 reactions. The reduction threshold used in LES was obtained a priori by using auto-ignition model and partially stirred reactor (PaSR) with pairwise mixing model. LES results with CoDAC are in good agreement with experimental data and those without reduction. The conditional mean of the number of selected species indicates that a large size of locally reduced mechanism is required in the reaction zone where CH4 is destructed. A computational time analysis shows that the PaSR model predicts better than the auto-ignition model on the wall time reduction with CoDAC in LES. |
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| Keywords: | Turbulent combustion large eddy simulation non-premixed jet flame correlated dynamic adaptive chemistry chemical model reduction |
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