Direct numerical simulation of high pressure turbulent lean premixed CH4/H2 – Air slot flames

Cecere, D.; Giacomazzi, E.; Arcidiacono, N.; Picchia, F.R.

doi:10.1016/j.ijhydene.2018.01.109

Cited by 18 publications

(9 citation statements)

References 39 publications

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“…5c. As far as the present simulations of negative displacement speed are concerned, these results obtained in the simplest case of a constant-density, single-reaction wave are consistent with earlier computations of negative S d in 2D DNS of complex-chemistry premixed turbulent flames (Gran et al 1996;Echekki and Chen 1996;Peters et al 1998;Echekki and Chen 1999;Cecere et al 2018), 3D DNS of single-step-chemistry premixed turbulent flames (Chakraborty and Cant 2005;Chakraborty 2007), and 3D DNS of complex-chemistry premixed turbulent flames (Wang et al 2017;Luca et al 2019;Sankaran et al 2015;Cecere et al 2016;Trisjono et al 2016).…”

supporting

confidence: 91%

“…It is also common to decompose the displacement speed into three component contributions due to reaction, diffusion in the normal direction, and tangential diffusion induced by curvature (Chen and Im 1998;Peters et al 1998;Echekki and Chen 1999). Particular focus has been put on the probability of finding locally negative displacement speed (Gran et al 1996;Echekki and Chen 1996;Peters et al 1998;Echekki and Chen 1999;Chakraborty and Cant 2005;Wang et al 2017;Luca et al 2019;Chakraborty 2007;Sankaran et al 2015;Cecere et al 2016;Trisjono et al 2016;Cecere et al 2018) as well as the sign of the averaged displacement speed. While previous studies that compare quantities extracted from DNS data contributed significantly to the understanding of turbulence/flame interactions, the mechanism governing the dynamic evolution of displacement speed is still not well understood.…”

Section: Introductionmentioning

confidence: 99%

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Assessment of an Evolution Equation for the Displacement Speed of a Constant-Density Reactive Scalar Field

Nilsson

Brethouwer

et al. 2020

Flow Turbulence Combust

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The displacement speed that characterises the self-propagation of isosurfaces of a reaction progress variable is of key importance for turbulent premixed reacting flow. The evolution equation for the displacement speed was derived in a recent work of Yu and Lipatnikov (Phys Rev E 100:013107, 2019a) for the case where the flame is described by a transport equation for single reaction progress variable assuming simple transport and one-step chemistry. This equation represents interaction of a number of complex coupled mechanisms related to straining by the velocity field, surface curvature and the scalar gradient. The aim of the current work is to provide detailed physical explanations of the displacement speed equation and its various terms, and to provide a new perspective to understand the mechanisms responsible for observed variations in the displacement speed. The equation is then used to analyze the propagation of a statistically planar reaction wave in homogeneous isotropic constant-density turbulence using direct numerical simulations. Additional emphasis is put on retracting surface segments that have a negative displacement speed, a phenomenon that commonly occurs at high Karlovitz numbers.

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supporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Assessment of an Evolution Equation for the Displacement Speed of a Constant-Density Reactive Scalar Field

Nilsson

Brethouwer

et al. 2020

Flow Turbulence Combust

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“…A collection of recent results dedicated to high pressure combustion can be found in [24]. As the flame thickness decreases, the stabilizing influence of the thermaldiffusive instability weakens and the hydrodynamic instability (also known as the Darrieus-Landau instability) becomes increasingly prominent, strongly convoluting the flame structure and therefore further complicating the estimation of the turbulent flame speed [21,[25][26][27].…”

Section: Nomenclaturementioning

confidence: 99%

Effect of non-ambient pressure conditions and Lewis number variation on direct numerical simulation of turbulent Bunsen flames at low turbulence intensity

Rasool

Chakraborty

Klein

2021

Combustion and Flame

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“…Among a group of lab-scale flames, the counterflow flame is a good platform to study NO formation, as the key parameters influencing the NO formation, such as the temperature, equivalence ratio, strain rate, etc., can be separately controlled in this configuration. Previous studies indicated that in laminar counterflow flames, an increase in hydrogen content leads to an increase in NO emission [8]. Shi et al found that a higher strain rate reduces NO emission [9].…”

Section: Introductionmentioning

confidence: 99%

NO and CO Emission Characteristics of Laminar and Turbulent Counterflow Premixed Hydrogen-Rich Syngas/Air Flames

Cheng,

Chen,

Pei

et al. 2024

Processes

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Burning hydrogen-rich syngas fuels derived from various sources in combustion equipment is an effective pathway to enhance energy security and of significant practical implications. Emissions from the combustion of hydrogen-rich fuels have been a main concern in both academia and industry. In this study, the NO and CO emission characteristics of both laminar and turbulent counterflow premixed hydrogen-rich syngas/air flames were experimentally and numerically studied. The results showed that for both laminar and turbulent counterflow premixed flames, the peak NO mole fraction increased as the equivalence ratio increased from 0.6 to 1.0 and decreased as the strain rate increased. Compared with the laminar flames at the same bulk flow velocity, turbulent flames demonstrated a lower peak NO mole fraction but broader NO formation region. Using the analogy theorem, a one-dimensional turbulent counterflow flame model was established, and the numerical results indicated that the small-scale turbulence-induced heat and mass transport enhancements significantly affected NO emission. Considering NO formation at the same level of fuel consumption, the NO formation of the turbulent flame was significantly lower than that of the laminar flame at the same level of fuel consumption, implying that the turbulence-induced heat and mass transfer enhancement favored NOx suppression.

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Direct numerical simulation of high pressure turbulent lean premixed CH4/H2 – Air slot flames

Cited by 18 publications

References 39 publications

Assessment of an Evolution Equation for the Displacement Speed of a Constant-Density Reactive Scalar Field

Assessment of an Evolution Equation for the Displacement Speed of a Constant-Density Reactive Scalar Field

Effect of non-ambient pressure conditions and Lewis number variation on direct numerical simulation of turbulent Bunsen flames at low turbulence intensity

NO and CO Emission Characteristics of Laminar and Turbulent Counterflow Premixed Hydrogen-Rich Syngas/Air Flames

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