Numerical study of a high-hydrogen micromix model burner using flamelet-generated manifold. (17th June 2021)

• Record Type: Journal Article
• Authors: Liu, Xunwei; Shao, Weiwei; Liu, Ce; Bi, Xiaotian; Liu, Yan; Xiao, Yunhan
• Is Part Of: International journal of hydrogen energy. Volume 46:Number 39(2021)
• Page Start: 20750
• Page End: 20764
• Publication Date: 2021-06-17
• Subjects: Micro-mixing combustion -- Flamelet-generated manifolds -- Preferential diffusion -- Hydrogen-rich burner -- Parallel-jet flame; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.03.157
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The flamelet-generated manifolds (FGM) method was adopted in this study to consider the preferential diffusion in a high-hydrogen micro-mixing model burner. That is, when solving the FGM flamelet, accurate diffusion rate was obtained from two methods: multicomponent formulation and constant detailed Lewis numbers assumption. Then a new method of filling the thermochemical state and the source term in the mixture fraction and the process variable space also was proposed, namely the linear triangular dissection interpolation method, to predict the position of the hydrogen-rich micro-mixing flame front. Compared with the Fluent approach to establish the diffusion FGM flamelet, the results showed that the two FGMs have similar flame predictions in high hydrogen content fuels, and both can accurately capture the location of the internal and external shear layer boundaries of the micro-mixing multi-jet flame in the steady state, while the Fluent approach based on the uniform Lewis number assumption predicts results that deviated significantly from the experimental results. However, for the internal shear layer, both methods have large predicted OH gradients compared to the experimental results due to the lack of effective Lewis number correction for the control variable transport equation. The results using linear triangular dissection interpolation maybe superior to the method with linear interpolation of the process variable quenching boundary toward zero, which leads to flashback due to overestimation of the process variable source term in the region below the diffusion FGM quenching boundary. Graphical abstract: Image 1 Highlights: Flamelet-generated manifolds method was adopted for simulation. The high-hydrogen preferential diffusion was partial considered. A new interpolation method was used during flamelet generation. A huge difference appears with or without detailed Lewis number. Assuming detailed Lewis numbers can simplify the diffusion calculation.