Fuel and chemistry effects in high Karlovitz premixed turbulent flames

Lapointe, Simon; Blanquart, Guillaume

doi:10.1016/j.combustflame.2016.01.035

Cited by 60 publications

(43 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. Recent DNS of premixed flames in very intense turbulence also indicated transition from thin to distributed reaction zones at very high Ka [10,47].…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Direct numerical simulation study of statistically stationary propagation of a reaction wave in homogeneous turbulence

Lipatnikov

2017

Phys. Rev. E

View full text Add to dashboard Cite

A three-dimensional (3D) direct numerical simulation (DNS) study of the propagation of a reaction wave in forced, constant-density, statistically stationary, homogeneous, isotropic turbulence is performed by solving Navier-Stokes and reaction-diffusion equations at various (from 0.5 to 10) ratios of the rms turbulent velocity U to the laminar wave speed, various (from 2.1 to 12.5) ratios of an integral length scale of the turbulence to the laminar wave thickness, and two Zeldovich numbers Ze = 6.0 and 17.1. Accordingly, the Damköhler and Karlovitz numbers are varied from 0.2 to 25.1 and from 0.4 to 36.2, respectively. Contrary to an earlier DNS study of self-propagation of an infinitely thin front in statistically the same turbulence, the bending of dependencies of the mean wave speed on U is simulated in the case of a nonzero thickness of the local reaction wave. The bending effect is argued to be controlled by inefficiency of the smallest scale turbulent eddies in wrinkling the reaction-zone surface, because such small-scale wrinkles are rapidly smoothed out by molecular transport within the local reaction wave.

show abstract

“…3. Recent DNS of premixed flames in very intense turbulence also indicated transition from thin to distributed reaction zones at very high Ka [10,47].…”

Section: Resultsmentioning

confidence: 99%

“…Progress made in this area over the past years was very impressive. In particular, the leading research groups succeeded already in 3D DNSs of highly turbulent premixed flames by allowing for density variations and complex combustion chemistry [4][5][6][7][8][9][10]. Moreover, DNS of laboratory flames were also performed [11,12].…”

Section: Introductionmentioning

confidence: 99%

Direct numerical simulation study of statistically stationary propagation of a reaction wave in homogeneous turbulence

Lipatnikov

2017

Phys. Rev. E

View full text Add to dashboard Cite

show abstract

“…This is because calculating diffusion fluxes requires point-wise knowledge of the multicomponent diffusion coefficient matrix, which scales with the number of chemical species squared [1]. The unity Lewis number, non-unity Lewis number, and mixture-averaged diffusion assumptions have been used to reduce the costs associated with mass diffusion by approximating the full diffusion coefficient matrix as a constant scalar value, a constant vector, and a matrix diagonal, respectively [1][2][3][4]. In addition, several approaches, such as those used by Warnatz [5] and Coltrin et al [6], further reduce the system's complexity by approximating multicomponent diffusion processes in terms of equivalent Fickian processes.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…As further motivation for this study, Lapointe and Blanquart [3] recently investigated the impact of differential diffusion on simulations using unity and nonunity Lewis number approximations. They reported that methane, n-heptane, iso-octane, and toluene flames have similar normalized turbulent flame speeds and fuel burning rates when neglecting differential diffusion, but flames using the nonunity Lewis number approximation underpredict the normalized flame speed when including differential diffusion due to reduced burning rates [3]. Building on these results, Burali et al [2] evaluated the relative accuracy of the nonunity Lewis number assumption relative to mixture-averaged diffusion for lean, unstable hydrogen/air flames; lean, turbulent n-heptane/air flames; and ethylene/air coflow diffusion flames.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A fast, low-memory, and stable algorithm for implementing multicomponent transport in direct numerical simulations

Fillo

Schlup

Beardsell

et al. 2020

Journal of Computational Physics

Self Cite

View full text Add to dashboard Cite

Implementing multicomponent diffusion models in reacting-flow simulations is computationally expensive due to the challenges involved in calculating diffusion coefficients. Instead, mixture-averaged diffusion treatments are typically used to avoid these costs. However, to our knowledge, the accuracy and appropriateness of the mixture-averaged diffusion models has not been verified for three-dimensional turbulent premixed flames. In this study we propose a fast, efficient, low-memory algorithm and use that to evaluate the role of multicomponent mass diffusion in reacting-flow simulations. Direct numerical simulation of these flames is performed by implementing the Stefan-Maxwell equations in NGA. A semi-implicit algorithm decreases the computational expense of inverting the full multicomponent ordinary diffusion array while maintaining accuracy and fidelity. We demonstrate the algorithm to be stable, and its performance scales approximately with the number of species squared. We first verify the method by performing one-dimensional simulations of premixed hydrogen flames and compare with matching cases in Cantera. As an initial study of multicomponent diffusion, we simulate premixed, three-dimensional turbulent hydrogen flames, neglecting secondary Soret and Dufour effects. Simulation conditions are carefully selected to match previously published results and ensure valid comparison. Our results show that using the mixture-averaged diffusion assumption lead to a 15 % under-prediction of the normalized turbulent flame speed for premixed hydrogen air flames. This large difference in the turbulent flame speed raises questions on the appropriateness of using the mixture-averaged diffusion assumption for DNS of moderate to high Karlovitz number flames.

show abstract

Turbulent Hydrogen Flames: Physics and Modeling Implications

Song

Pérez

2023

Hydrogen for Future Thermal Engines

View full text Add to dashboard Cite

Fuel and chemistry effects in high Karlovitz premixed turbulent flames

Abstract: Fig. 3: Two-dimensional slices of a 5L × L region centered around the flame showing temperature for the different equivalence ratios non-unity Lewis number cases. The temperature range is [298, 2200].

Cited by 60 publications

References 47 publications

Direct numerical simulation study of statistically stationary propagation of a reaction wave in homogeneous turbulence

Direct numerical simulation study of statistically stationary propagation of a reaction wave in homogeneous turbulence

A fast, low-memory, and stable algorithm for implementing multicomponent transport in direct numerical simulations

Turbulent Hydrogen Flames: Physics and Modeling Implications

Contact Info

Product

Resources

About