Large Eddy Simulation of a Premixed Bunsen Flame Using a Modified Thickened-Flame Model at Two Reynolds Number

De, Ashoke; Acharya, Sumanta

doi:10.1080/00102200903076266

Cited by 25 publications

(47 citation statements)

References 25 publications

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“…The results of previous numerical studies are also included in this figure. The thickened flame-LES results of De and Acharya (2009) agree very well with the measurements for x 6:5D for the high Da flame F3 and these computational results gradually move away from the experimental data as seen in this figure for the flame F1. However, the results of Wang et al (2011) using a dynamic thickened flame approach show a good agreement uniformly.…”

Section: Cflsupporting

confidence: 76%

“…A small velocity of 0.2 m/s is assigned to the coflowing air to mimic the air entrainment and a 25% change to this velocity is observed to influence the LES statistics negligibly. The pilot temperature is unspecified in the experimental study and values ranging from 1785 to 2248 K were used in past studies (Amzin et al, 2012;De and Acharya, 2009;Dodoulas and Navarro-Martinez, 2013;Herrmann, 2006;Kolla and Swaminathan, 2010b;Lindstedt and Vaos, 2006;Pitsch and de Lagneste, 2002;Prasad and Gore, 1999;Salehi and Bushe, 2010;Salehi et al, 2012;Heinz, 2008, 2010;Wang et al, 2011;Yilmaz et al, 2010) suggesting that the heat loss to the pilot burner varies from 0 (De and Acharya, 2009) to 34% (Dodoulas and Navarro-Martinez, 2013;Lindstedt and Vaos, 2006). A value of 17% was used by Herrmann (2006) and 20% heat loss was assumed by Pitsch and de Lagneste (2002) and Wang et al (2011).…”

Section: Boundary and Initial Conditionsmentioning

confidence: 99%

“…The current statistics are also compared to past results available in the literature. A 2-step chemistry with empirical rate expression was used by De and Acharya (2009) and 1-step chemistry was used by Wang et al (2011). The LES-PDF study by Dodoulas and NavarroMartinez (2013) used a 4-step, 15-step, and GRI3.0 mechanisms and the results of the 15-step mechanism are used here.…”

Section: Cflmentioning

confidence: 99%

“…Three piloted stoichiometric methane-air Bunsen flames of Chen et al (1996) considered in many past RANS (Amzin et al, 2012;Herrmann, 2006;Kolla and Swaminathan, 2010b;Lindstedt and Vaos, 2006;Prasad and Gore, 1999;Salehi and Bushe, 2010;Salehi et al, 2012;Heinz, 2008, 2010) and LES (De and Acharya, 2009;Dodoulas and Navarro-Martinez, 2013;Langella et al, 2015;Pitsch and de Lagneste, 2002;Wang et al, 2011;Yilmaz et al, 2010) studies are chosen for this investigation. The reactant jet with a diameter of D = 12 mm issues into quiescent air and the flame is stabilized by laminar pilot flames of the same mixture.…”

Section: Experimental Casesmentioning

confidence: 99%

“…These approaches can be broadly categorized into two classes, namely, flamelets and non-flamelets or geometrical and statistical (Gicquel et al, 2012). The geometrical category of flamelets includes thickened flame (Colin et al, 2000;De and Acharya, 2009), flame surface density or flame-wrinkling (see, for example, Boger et al 1998;Chakraborty and Cant 2007;Chakraborty and Klein 2008;Gubba et al, 2012;Hawkes and Cant 2001;Knikker et al, 2004;Wang et al, 2012), and level-set or G equation (Moureau et al, 2008;Pitsch, 2005). The statistical category of flamelets includes approaches, such as EBU (eddy-break-up model), algebraic closure involving scalar dissipation rate (Butz et al, 2015;Dunstan et al, 2013;Gao et al, 2014;Langella et al, 2015;Ma et al, 2014), and presumed probability density function (PDF) methodology with laminar flamelets.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Large Eddy Simulation of Premixed Combustion: Sensitivity to Subgrid Scale Velocity Modeling

Langella

Swaminathan

Gao

et al. 2016

Combustion Science and Technology

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An algebraic reaction rate closure involving filtered scalar dissipation rate of reaction progress variable is studied. The filtered scalar dissipation rate closure requires a model for sub-grid scale velocity, u 0 Δ , which is estimated using four algebraic models and transported subgrid scale kinetic energy. A priori analyses using direct numerical simulation (DNS) data show that the filtered dissipation rate, and thus the reaction rate closure, has some sensitivity to the u 0 Δ model. The sensitivity of various statistics obtained from large eddy simulation (LES) of three piloted Bunsen flames of stoichiometric methaneair mixture to the modeling of u 0 Δ is observed to be weaker compared to that for the DNS analysis. Moreover, analysis using transported sub-grid scale kinetic energy does not indicate a necessity to include flame-generated turbulence in the modeling of u 0 Δ for the Bunsen flames in the thin reaction zones regime. The measured and computed flame brush structures are compared and studied and the algebraic closure for the filtered reaction rate is found to be quite good. ARTICLE HISTORY

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Section: Cflsupporting

confidence: 76%

Section: Boundary and Initial Conditionsmentioning

confidence: 99%

Section: Cflmentioning

confidence: 99%

Section: Experimental Casesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Large Eddy Simulation of Premixed Combustion: Sensitivity to Subgrid Scale Velocity Modeling

Langella

Swaminathan

Gao

et al. 2016

Combustion Science and Technology

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Numerical Simulations of Dynamics of Premixed Hydrogen-Air Flames Propagating in Ducts

Xiao

2015

Experimental and Numerical Study of Dynamics of Premixed Hydrogen-Air Flames Propagating in Ducts

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A Posteriori Assessment of Algebraic Scalar Dissipation Models for RANS Simulation of Premixed Turbulent Combustion

Ahmed

Prosser

2017

Flow Turbulence Combust

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Citation for published version (APA):Ahmed, U., & Prosser, R. (2017). A posteriori assessment of algebraic scalar dissipation models for RANS simulation of premixed turbulent combustion. Flow, Turbulence and Combustion. https://doi.Abstract This paper examines the effects of scalar dissipation rate modelling on mean reaction rate predictions in turbulent premixed flames. The sensitivity of the mean reaction rate is explored by using different closures for scalar dissipation and the sensitivity of the scalar dissipation models themselves is also examined with respect to their defining constants. The influence of different scalar dissipation models on the flame location and mean velocities is reported and compared with experimental results. The predicted reaction rate is found to be sensitive to the choice of closure used for scalar dissipation and also to the respective constants used in the scalar dissipation models. It is also found that the scalar dissipation models involving chemical and turbulent time scales yield a more physically plausible reaction rate when compared with the scalar dissipation models relying only on the turbulent time scale.Keywords Algebraic scalar dissipation models · Flame turbulence interaction · RANS simulation of premixed turbulent combustion · Premixed turbulent combustion · Turbulence scalar interaction 1 Introduction Accurate prediction of the mean reaction rate using computational methods remains a challenge for premixed turbulent combustion, and usually requires the use of statistical methods. There is a strong coupling between turbulence and chemistry in premixed flames and several modelling strategies have been developed to account for their interaction. In many cases, the total aerothermochemistry of the flow can be described via a Probability Density Function (PDF) and a multidimensional PDF can in principal be obtained by a PDF transport equation [31,59]. This procedure circumvents a number of modelling assumptions and consequently produces quite general reaction rate models. However the method requires a closure for the molecular diffusion terms which remains a modelling challenge [31]. Conditional Moment Closure (CMC) is another method which provides an alternative strategy for closing the reaction rate [39]. This method was originally developed for non-premixed combustion [16,51] and recently has been extended to account for premixed combustion [5,4,49]. One of the major challenges encountered by the CMC approach in premixed combustion is the modelling of the conditional scalar dissipation rate [43].

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Large Eddy Simulation of a Premixed Bunsen Flame Using a Modified Thickened-Flame Model at Two Reynolds Number

Cited by 25 publications

References 25 publications

Large Eddy Simulation of Premixed Combustion: Sensitivity to Subgrid Scale Velocity Modeling

Large Eddy Simulation of Premixed Combustion: Sensitivity to Subgrid Scale Velocity Modeling

Numerical Simulations of Dynamics of Premixed Hydrogen-Air Flames Propagating in Ducts

A Posteriori Assessment of Algebraic Scalar Dissipation Models for RANS Simulation of Premixed Turbulent Combustion

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