Large-eddy simulation/probability density function modeling of a non-premixed CO/H2 temporally evolving jet flame

Yang, Yue; Wang, Haifeng; Pope, Stephen B.; Chen, Jacqueline H.

doi:10.1016/j.proci.2012.08.015

Cited by 77 publications

(46 citation statements)

References 33 publications

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“…1b), we employ the LES/PDF methodology through the coupled NGA/HPDF code [27][28][29][30]. The LES approach is used to treat the flow and turbulence [14,15], while the PDF approach is used to treat the chemistry and the turbulence-chemistry interactions [16].…”

Section: Computational Methodologymentioning

confidence: 99%

“…All species diffusivities are taken to be equal to the thermal diffusivity under the unity Lewis number assumption. More details of the methodology and code implementation can be found in [14][15][16][27][28][29][30]. More details about the application of the coupled code to the turbulent counterflow configuration can be found in [33].…”

Section: Computational Methodologymentioning

confidence: 99%

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A Simple Approach for Specifying Velocity Inflow Boundary Conditions in Simulations of Turbulent Opposed-Jet Flows

Tirunagari

Pettit

Kempf³

et al. 2016

Flow Turbulence Combust

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A new methodology is developed to specify inflow boundary conditions for the velocity field at the nozzle exit planes in turbulent counterflow simulations. The turbulent counterflow configuration consists of two coaxial opposed nozzles which emit highlyturbulent streams of varying species compositions depending on the mode considered. The specification of velocity inflow boundary conditions at the nozzle exits in the counterflow configuration is non-trivial because of the unique turbulence field generated by the turbulence generating plates (TGPs) upstream of the nozzle exits. In the method presented here, a single large-eddy simulation (LES) is performed in a large domain that spans the region between the TGPs of the nozzles, and the time series of the velocity fields at the nozzle exit planes are recorded. To provide inflow boundary conditions at the nozzle exit planes for simulations under other conditions (e.g., different stream compositions, bulk velocity, TGP location), transformations are performed on the recorded time series: the mean and r.m.s. (root-mean-square) quantities of velocity, as well as the longitudinal integral length scale on the centerline, at the nozzle exits in simulations are matched to those observed in experiments, thereby matching the turbulent Reynolds number Re t . The method is assessed by implementing it in coupled large-eddy simulation/probability density function (LES/PDF) simulations on a small cylindrical domain between the nozzle exit planes for three different modes of the counterflow configuration: N 2 vs. N 2 ; N 2 vs. hot combustion products; Ranjith R. Tirunagari Flow Turbulence Combust and CH 4 /N 2 vs. O 2 . The inflow method is found to be successful as the first and second moments of velocity from the LES/PDF simulations agree well with the experimental data on the centerline for all three modes. This simple yet effective inflow strategy can be applied to eliminate the computational cost required to simulate the flow field upstream of the nozzle exits. It is also emphasized that, in addition to the predicted time series data, the availability of experimental data close to the nozzle exit planes plays a key role in the success of this method.

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Section: Computational Methodologymentioning

confidence: 99%

Section: Computational Methodologymentioning

confidence: 99%

A Simple Approach for Specifying Velocity Inflow Boundary Conditions in Simulations of Turbulent Opposed-Jet Flows

Tirunagari

Pettit

Kempf³

et al. 2016

Flow Turbulence Combust

Self Cite

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“…A detailed description of this mechanism is given in Table 2. The computation of the reaction rate source terms is accelerated with the ISAT algorithm [4] embodied in the solver.…”

Section: Combustion Modelmentioning

confidence: 99%

“…Plane or axisymmetric bluff-body stabilizers are popular arrangements for experimental and computational flame stabilization studies under nonpremixed [2,4] and fully premixed configurations [5,6]. Swirl motion is an equally common method of stabilization in industrial burners.…”

Section: Introductionmentioning

confidence: 99%

The Impact of Variable Inlet Mixture Stratification on Flame Topology and Emissions Performance of a Premixer/Swirl Burner Configuration

Koutmos

Paterakis

Dogkas

et al. 2012

Journal of Combustion

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The work presents the assessment of a low emissions premixer/swirl burner configuration utilizing lean stratified fuel preparation. An axisymmetric, single-or double-cavity premixer, formed along one, two, or three concentric disks promotes propane-air premixing and supplies the combustion zone at the afterbody disk recirculation with a radial equivalence ratio gradient. The burner assemblies are operated with a swirl co-flow to study the interaction of the recirculating stratified flame with the surrounding swirl. A number of lean and ultra-lean flames operated either with a plane disk stabilizer or with one or two premixing cavity arrangements were evaluated over a range of inlet mixture conditions. The influence of the variation of the imposed swirl was studied for constant fuel injections. Measurements of turbulent velocities, temperatures, OH * chemiluminescence and gas analysis provided information on the performance of each burner set up. Comparisons with Large Eddy Simulations, performed with an 11-step global chemistry, illustrated the flame front interaction with the vortex formation region under the influence of the variable inlet mixture stratifications. The combined effort contributed to the identification of optimum configurations in terms of fuel consumption and pollutants emissions and to the delineation of important controlling parameters and limiting fuel-air mixing conditions.

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“…In addition, those databases have supported the assessment of selected assumptions and components of existing subfilter models with tangible improvements to the predictions. Pertinent examples include the recent advances in methods and models for the subfilter probability density function [8], transported filtered density function [9], scalar dissipation rate [10] and premixed flame propagation [11][12][13]. In the context of subfilter model development, spatially and temporally resolved joint statistics of multiple fields and their gradients are desirable, so that the data available from DNS are unique and unmatched even by the most advanced laser-based diagnostics for turbulent combustion [14].…”

Section: Introductionmentioning

confidence: 99%

Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations

Bisetti

Attili

Pitsch

2014

Phil. Trans. R. Soc. A.

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Combustion of fossil fuels is likely to continue for the near future due to the growing trends in energy consumption worldwide. The increase in efficiency and the reduction of pollutant emissions from combustion devices are pivotal to achieving meaningful levels of carbon abatement as part of the ongoing climate change efforts. Computational fluid dynamics featuring adequate combustion models will play an increasingly important role in the design of more efficient and cleaner industrial burners, internal combustion engines, and combustors for stationary power generation and aircraft propulsion. Today, turbulent combustion modelling is hindered severely by the lack of data that are accurate and sufficiently complete to assess and remedy model deficiencies effectively. In particular, the formation of pollutants is a complex, nonlinear and multi-scale process characterized by the interaction of molecular and turbulent mixing with a multitude of chemical reactions with disparate time scales. The use of direct numerical simulation (DNS) featuring a state of the art description of the underlying chemistry and physical processes has contributed greatly to combustion model development in recent years. In this paper, the analysis of the intricate evolution of soot formation in turbulent flames demonstrates how DNS databases are used to illuminate relevant physico-chemical mechanisms and to identify modelling needs.

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Large-eddy simulation/probability density function modeling of a non-premixed CO/H2 temporally evolving jet flame

Cited by 77 publications

References 33 publications

A Simple Approach for Specifying Velocity Inflow Boundary Conditions in Simulations of Turbulent Opposed-Jet Flows

A Simple Approach for Specifying Velocity Inflow Boundary Conditions in Simulations of Turbulent Opposed-Jet Flows

The Impact of Variable Inlet Mixture Stratification on Flame Topology and Emissions Performance of a Premixer/Swirl Burner Configuration

Advancing predictive models for particulate formation in turbulent flames via massively parallel direct numerical simulations

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