دورية أكاديمية

The Effects of Differential Diffusion on Turbulent Non-Premixed Flames LO 2 /CH 4 under Transcritical Conditions Using Large-Eddy Simulation.

التفاصيل البيبلوغرافية
العنوان: The Effects of Differential Diffusion on Turbulent Non-Premixed Flames LO 2 /CH 4 under Transcritical Conditions Using Large-Eddy Simulation.
المؤلفون: Wang, Siyuan, Wang, Haiou, Luo, Kun, Fan, Jianren
المصدر: Energies (19961073); Feb2023, Vol. 16 Issue 3, p1065, 17p
مصطلحات موضوعية: PHASE transitions, FLAME, CHEMICAL reactions, DIFFUSION, CRITICAL temperature, DIFFUSION coefficients, OFFICES
مستخلص: In this paper, a large-eddy simulation (LES) of turbulent non-premixed LO2/CH4 combustion under transcritical conditions is performed based on the Mascotte test rig from the Office National d'Etudes et de Recherches A e ´ rospatiales (ONERA), and the aim is to understand the effects of differential diffusion on the flame behaviors. In the LES, oxygen was injected into the environment above the critical pressure while the temperature was below the critical temperature. The flamelet/progress variable (FPV) approach was used as the combustion model. Two LES cases with different species diffusion coefficient schemes—i.e., non-unity and unity Lewis numbers—for generating the flamelet tables were carried out to explore the effects of differential diffusion on the flame and flow structures. The results of the LES case with non-unity Lewis numbers were in good agreement with the experimental data. It was shown that differential diffusion had evident impacts on the flame structure and flow dynamics. In particular, when unity Lewis numbers were used to evaluate the species diffusion coefficient, the flame length was underestimated and the flame expansion was more significant. Compared to laminar counterflow flames, turbulence in jet flames allows chemical reactions to take place in a wider range of mixture fractions. The density distributions of the two LES cases in the mixture fraction space were very similar, indicating that differential diffusion had no significant effects on the phase transition under transcritical conditions. [ABSTRACT FROM AUTHOR]
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قاعدة البيانات: Complementary Index
الوصف
تدمد:19961073
DOI:10.3390/en16031065