The mathematical modelling of premixed turbulent combustion

Bradley, D.; Lau, A. K. C.

doi:10.1351/pac199062050803

Cited by 24 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Arrows indicate velocities of planar stagnation flow. At low to moderate strain rates, the reaction zone of the flame (indicated by the right line) is to the right of the stagnation point of the flow products [7][8][9][10][40][41][42][43][44]. In both cases, the strain rate is uniform over the flame surface with no curvature effects.…”

Section: Introductionmentioning

confidence: 99%

“…In an asymmetric configuration, on the other hand, enhanced diffusion of radicals H, OH and O caused by the increase of strain generates a reduction in the radical pool [42][43][44], decreasing the consumption of the reactants. However, the reaction zone is maintained even for high strain rates due to the hot temperatures of the combustion products [9,40]. Thus, an "extinction" event and the corresponding critical strain rate are difficult to identify.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

Tay-Wo-Chong

Zellhuber

Komarek

et al. 2015

Flow Turbulence Combust

View full text Add to dashboard Cite

The present paper argues that the prediction of turbulent premixed flames under non-adiabatic conditions can be improved by considering the combined effects of strain and heat loss on reaction rates. The effect of strain in the presence of heat loss on the consumption speed of laminar premixed flames was quantified by calculations of asymmetric counterflow configurations ("fresh-to-burnt") with detailed chemistry. Heat losses were introduced by setting the temperature of the incoming stream of products on the "burnt" side to values below those corresponding to adiabatic conditions. The consumption speed decreased in a roughly exponential manner with increasing strain rate, and this tendency became more pronounced in the presence of heat losses. An empirical relation in terms of Markstein number, Karlovitz Number and a non-dimensional heat loss parameter was proposed for the combined influence of strain and heat losses on the consumption speed. Combining this empirical relation with a presumed probability density function for strain in turbulent flows, an attenuation factor that accounts for the effect of strain and heat loss on the reaction rate in turbulent flows was deduced and implemented into a turbulent combustion model. URANS simulations of a premixed swirl burner were carried out and validated against flow field and OH chemiluminescence measurements. Introducing the effects of Wolfgang Polifke Flow Turbulence Combust strain and heat loss into the combustion model, the flame topology observed experimentally was correctly reproduced, with good agreement between experiment and simulation for flow field and flame length.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

Tay-Wo-Chong

Zellhuber

Komarek

et al. 2015

Flow Turbulence Combust

View full text Add to dashboard Cite

show abstract

“…Mean values of reaction progress and chemical species are obtained by integration over a detailed chemical kinetic laminar flame structure, weighted with the presumed PDF of the reaction progress variable. The influence of turbulent strain on mean reaction progress was taken into account by considering strained laminar flames and/or extinction at a critical strain rate [15]. In the mid-90s, this approach was used at ABB to model (partially) premixed combustion in gas turbines, including the case of nonhomogeneous mixture fraction [16,17].…”

Section: Model Formulationmentioning

confidence: 99%

“…The source termω Yc for the progress variable Y c must be computed with detailed chemistry in a preprocessing step and tabulated as a function of the parameters that control reaction progress. With the "steady laminar flamelet" approach as originally proposed by Bradley and coworkers [14,15], these parameters are progress variable Y c , possibly complemented by mixture fraction Z and flame strain a or scalar dissipation χ. Detailed chemistry data for (partially) premixed or nonpremixed combustion are thus typically generated by solving 1-dimensional reactive-diffusive model configurations, for example, propagating or strained flames.…”

Section: Definition and Tabulation Of Progress Variablementioning

confidence: 99%

Large Eddy Simulation of Autoignition in a Turbulent Hydrogen Jet Flame Using a Progress Variable Approach

Kulkarni

Polifke

2012

Journal of Combustion

View full text Add to dashboard Cite

The potential of a progress variable formulation for predicting autoignition and subsequent kernel development in a nonpremixed jet flame is explored in the LES (Large Eddy Simulation) context. The chemistry is tabulated as a function of mixture fraction and a composite progress variable, which is defined as a combination of an intermediate and a product species. Transport equations are solved for mixture fraction and progress variable. The filtered mean source term for the progress variable is closed using a probability density function of presumed shape for the mixture fraction. Subgrid fluctuations of the progress variable conditioned on the mixture fraction are neglected. A diluted hydrogen jet issuing into a turbulent coflow of preheated air is chosen as a test case. The model predicts ignition lengths and subsequent kernel growth in good agreement with experiment without any adjustment of model parameters. The autoignition length predicted by the model depends noticeably on the chemical mechanism which the tabulated chemistry is based on. Compared to models using detailed chemistry, significant reduction in computational costs can be realized with the progress variable formulation.

show abstract

“…Furthermore, premixed flamelets have been used to tabulate chemistry in turbulent combustion modelling for both premixed and non-premixed flames. 13,14 The Flame Prolongation of ILDM (FPI) 15,16 and Flame Generated Manifold (FGM) 17 are two recently proposed approaches based on tabulation of premixed flamelets. Both of these approaches have been developed and applied successfully to different combustion regimes and are of considerable current interest as they are unifying methods that may be applied to both premixed and non-premixed flames.…”

Section: Introductionmentioning

confidence: 99%

Parallel Solution Adaptive Scheme for Three-Dimensional Turbulent Diffusion Flames with Detailed Tabulated Chemistry

Jha

Groth

2011

20th AIAA Computational Fluid Dynamics Conference

View full text Add to dashboard Cite

Mathematical modelling of the effects of turbulence on detailed-chemistry is an important issue in the accurate and reliable numerical prediction of turbulent combustion processes. The highly non-linear nature of both turbulence and chemistry make this extremely challenging. In this study, a Presumed Conditional Moment (PCM) approach, based on a β probability density function (PDF), is combined with the Flame Prolongation of ILDM (FPI) tabulation method to model the effects of turbulence and detailedchemistry for diffusion flames. The recently proposed FPI scheme incorporates the effects of the detailed-chemistry on the local flow field for laminar flames through the use of two independent scalars: mixture fraction and progress variable and their variances. The Favre-Averaged Navier-Stokes (FANS) equations, based on the two-equation k-ω turbulence model, are used herein to model the effects of the unresolved turbulence on the mean flow field. The governing partial-differential equations for mean quantities are solved using a parallel, Adaptive Mesh Refinement (AMR), fully-coupled finite-volume formulation on body-fitted, multi-block, hexahedral mesh for three-dimensional flow geometries. Two approaches for coupling the PCM-FPI approach with the parallel AMR finite-volume solution method are considered. The PCM-FPI results are compared to experimental data for both reacting and non-reacting flows associated with a Sydney bluff-body burner configuration. The computational cost of the PCM-FPI scheme is compared to the cost of the simplified Eddy Dissipation Model (EDM). A full description of the proposed numerical solution scheme for turbulent non-premixed flames is provided along with an evaluation and demonstration of its computational performance and predictive capabilities.

show abstract

The mathematical modelling of premixed turbulent combustion

Abstract: Abstract

Cited by 24 publications

References 0 publications

Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

Combined Influence of Strain and Heat Loss on Turbulent Premixed Flame Stabilization

Large Eddy Simulation of Autoignition in a Turbulent Hydrogen Jet Flame Using a Progress Variable Approach

Parallel Solution Adaptive Scheme for Three-Dimensional Turbulent Diffusion Flames with Detailed Tabulated Chemistry

Contact Info

Product

Resources

About