Scalar gradient and flame propagation statistics of a flame-resolved laboratory-scale turbulent stratified burner simulation

A Priori Direct Numerical Simulation Analysis of the Closure of Cross-Scalar Dissipation Rate of Reaction Progress Variable and Mixture Fraction in Turbulent Stratified Flames

“…It is worth noting that the statistical behaviour of N c = D(∇c ⋅ ∇ ) determines the behaviour of A . The cross-scalar dissipation rate values are often smaller than the values of scalar dissipation rate of the reaction progress variable (Malkeson and Chakraborty, 2010a;Inanc et al, 2022). However, the cross-scalar dissipation rate appears explicitly in the expression of displacement speed S d = |∇c| −1 (Dc∕Dt) in stratified flames (Bray et al, 2005;Malkeson and Chakraborty, 2010b) and this quantity accounts for the effects of relative orientations of ∇c and ∇ on flame propagation (i.e.…”

Implications of Using Scalar Forcing to Sustain Reactant Mixture Stratification in Direct Numerical Simulations of Turbulent Combustion

“…Proch et al [17] and Inanc et al [18] carried out flame-resolved three-dimensional high-fidelity simulations of turbulent stratified-mixture combustion of a laboratory-scale configuration used in experiments by Barlow et al [20] and Sweeney et al [21,22]. The aforementioned DNS analyses on turbulent stratified-mixture combustion offered fundamental physical information on the stratified flame structure [1][2][3]5,8,13,16,18,19] and flame propagation rate [4,12,16,18]. This information was subsequently utilised to develop closure methodologies for scalar variances and co-variances [3,5,11], turbulent scalar flux [9], flame surface density [10,19], and scalar dissipation and cross-scalar dissipation rates [7,8,13].…”

“…Lipatnikov [14] and Domingo et al [15] provided an extensive review of experimental and numerical findings of stratified-mixture combustion. High-performance computing has enabled DNS of stratified-mixture combustion [1][2][3][4][5][6][7][8][9][10][11][12][13][16][17][18][19], and the vast majority of these studies have been conducted for statistically planar flames in canonical 'flame-in-a-box' configuration [1][2][3][4][5][6][7][8][9][10][11][12][13]. Richardson and Chen [16] and Brearley et al [19] analysed turbulent stratified-mixture combustion using three-dimensional DNS to analyse the effects of the relative alignments of equivalence ratio and reaction progress variable gradients on the global behaviours of burning, flame propagation rate and flame surface area and their modelling implications.…”

“…Richardson and Chen [16] and Brearley et al [19] analysed turbulent stratified-mixture combustion using three-dimensional DNS to analyse the effects of the relative alignments of equivalence ratio and reaction progress variable gradients on the global behaviours of burning, flame propagation rate and flame surface area and their modelling implications. Proch et al [17] and Inanc et al [18] carried out flame-resolved three-dimensional high-fidelity simulations of turbulent stratified-mixture combustion of a laboratory-scale configuration used in experiments by Barlow et al [20] and Sweeney et al [21,22]. The aforementioned DNS analyses on turbulent stratified-mixture combustion offered fundamental physical information on the stratified flame structure [1][2][3]5,8,13,16,18,19] and flame propagation rate [4,12,16,18].…”