A combined computational and experimental characterization of lean premixed turbulent low swirl laboratory flames II. Hydrogen flames

Day, Marc; Tachibana, Shigeru; Bell, John B.; Lijewski, Michael J.; Beckner, Vince; Cheng, R.K.

doi:10.1016/j.combustflame.2015.01.013

Cited by 54 publications

(13 citation statements)

References 33 publications

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“…Recent studies also investigate the dependence of S T on the low temperature fuel chemistry (Won et al 2014), high pressure (Bradley et al 2013; quantified variations of the vorticity and strain rate of fluid parcels undergoing combustion by tracking Lagrangian fluid particles and using the three-dimensional, timeresolved experimental measurement in premixed dimethyl-ether/air piloted jet flames. Day et al (2015) observed the complex nature of thermodynamic and chemical evolutions along Lagrangian trajectories, including the non-monotonic evolution of temperature within fluid parcels, in a joint experimental and computational study of lean hydrogen turbulent premixed flames in low swirl burners. Hamlington et al (2017) examined the effects of high-speed turbulence on the non-monotonic thermochemical trajectories in DNS of hydrogen-air premixed flames.…”

Section: Introductionmentioning

confidence: 99%

Modelling of the turbulent burning velocity based on Lagrangian statistics of propagating surfaces

You

Yang

2020

J. Fluid Mech.

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We propose a predictive model of the turbulent burning velocity S T in homogeneous isotropic turbulence (HIT) based on Lagrangian statistics of propagating surfaces. The propagating surfaces with a constant displacement speed are initially arranged on a plane, and they evolve in non-reacting HIT, behaving like the propagation of a planar premixed flame front. The universal constants in the model of S T characterize the enhancement of area growth of premixed flames by turbulence, and they are determined by Lagrangian statistics of propagating surfaces. The flame area is then modelled by the area of propagating surfaces at a truncation time. This truncation time signals the statistical stationary state of the evolutionary geometry of propagating surfaces, and it is modelled by an explicit expression using limiting conditions of very weak and strong turbulence. Another parameter in the model of S T characterizes the effect of fuel chemistry on S T , and it is pre-determined by very few available data points of S T from experiments or direct numerical simulation (DNS) in weak turbulence. The proposed model is validated using three DNS series of turbulent premixed flames with various fuels. The model prediction of S T generally agrees well with DNS in a wide range of premixed combustion regimes, and it captures the basic trends of S T in terms of the turbulence intensity, including the linear growth in weak turbulence and the 'bending effect' in strong turbulence.

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Section: Introductionmentioning

confidence: 99%

Modelling of the turbulent burning velocity based on Lagrangian statistics of propagating surfaces

You

Yang

2020

J. Fluid Mech.

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“…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]. However, while advancement to simulations of increasingly challenging problems was in the focus of the numerical combustion community over the past decade, unique opportunities offered by DNS for scrutinizing foundations of turbulent combustion models did not seem to be exploited in full measure.…”

Section: Introductionmentioning

confidence: 99%

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

Lipatnikov

2017

Phys. Rev. E

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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.

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“…The selected equivalence ratio of φ = 0.4 is characteristic of conditions investigated in low swirl burners [47,48]. Before presenting the two-and three-dimensional simulations, a one-dimensional analysis of this configuration is discussed in the following section.…”

Section: Premixed Hydrogen/air Flamementioning

confidence: 99%

Assessment of the constant non-unity Lewis number assumption in chemically-reacting flows

Burali

Lapointe

Bobbitt

et al. 2016

Combustion Theory and Modelling

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Accurate computation of molecular diffusion coefficients in chemically reacting flows can be an expensive procedure, and the use of constant non-unity Lewis numbers has been adopted often as a cheaper alternative. The goal of the current work is to explore the validity and the limitations of the constant non-unity Lewis number approach in the description of molecular mixing in laminar and turbulent flames. To carry out this analysis, three test cases have been selected, including a lean, highly unstable, premixed hydrogen/air flame, a lean turbulent premixed n-heptane/air flame, and a laminar ethylene/air coflow diffusion flame. For the hydrogen flame, both a laminar and a turbulent configuration have been considered. The three flames are characterised by Lewis numbers which are less than unity, greater than unity, and close to unity, respectively. For each flame, mixture-averaged transport simulations are carried out and used as reference data. The current analysis suggests that, for numerous combustion configurations, the constant non-unity Lewis number approximation leads to small errors when the set of Lewis numbers is chosen properly. For the selected test cases and our numerical framework, the reduction of computational cost is found to be minimal.

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A combined computational and experimental characterization of lean premixed turbulent low swirl laboratory flames II. Hydrogen flames

Cited by 54 publications

References 33 publications

Modelling of the turbulent burning velocity based on Lagrangian statistics of propagating surfaces

Modelling of the turbulent burning velocity based on Lagrangian statistics of propagating surfaces

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

Assessment of the constant non-unity Lewis number assumption in chemically-reacting flows

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