Effects of Turbulent Reynolds Number on the Displacement Speed Statistics in the Thin Reaction Zones Regime of Turbulent Premixed Combustion

Figure 12

Variation across the flame brush with Favre averaged reaction progress variable 𝑐̃=⟨𝜌𝑐⟩/⟨𝜌⟩ of the FSD curvature term 2⟨𝑆_𝑑𝜅_𝑚⟩_𝑠Σ_gen and its contributions (see (12c)) 2⟨(𝑆_𝑟+𝑆_𝑛)𝜅_𝑚⟩_𝑠Σ_gen and −4⟨𝐷𝜅^2𝑚⟩_𝑠Σ_gen; the FSD propagation term −∇⋅⟨𝑆_𝑑𝑁⟩_𝑠Σ_gen and its contributions (see (12d)) −∇⋅⟨(𝑆_𝑟+𝑆_𝑛)𝑁⟩_𝑠Σ_gen and 2∇⋅⟨𝐷𝜅_𝑚𝑁⟩_𝑠Σ_gen; together with the modelled curvature term 2⟨𝑆_𝐿𝜅_𝑚⟩_𝑠Σ_gen and propagation term −∇⋅⟨𝑆_𝐿𝑁⟩_𝑠Σ_gen for: (a) case A; (b) case B; (c) case C; (d) case D; (e) case E. All the terms are normalised with respect to 𝑆_𝐿/𝛿²_th of the respective cases.