Assessing multi-regime combustion in a novel burner configuration with large eddy simulations using tabulated chemistry

Popp, Sebastian; Hartl, S.; Butz, David; Geyer, D.; Dreizler, Andreas; Hasse, Christian

doi:10.1016/j.proci.2020.06.098

Cited by 24 publications

(11 citation statements)

References 24 publications

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“…Different levels of enthalpy have been included following the procedure described in [35] to account for the heat losses towards the walls. The flamelets are then tabulated and stored in a look-up library, which is accessed during runtime to retrieve thermochemical quantities needed for the solution of the momentum and scalar equations, similar to the approach in [36]. The thermochemical state is parametrized by the mixture fraction , the progress variable and the enthalpy ℎ resulting in the description = ( , , ℎ).…”

Section: Numerical Modeling a Combustion Modelmentioning

confidence: 99%

See 1 more Smart Citation

Soot Prediction in a Model Aero-Engine Combustor using a Quadrature-based Method of Moments

Cokuslu

Hasse

Geigle

et al. 2022

AIAA SCITECH 2022 Forum

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Numerical simulations of aero-engine combustors are extremely challenging due to the complex multiscale and multiphysics phenomena involved. Currently, reliable modeling and prediction of soot particle formation produced during incomplete hydrocarbon combustion is one of the major issues in combustion research. The next generation of gas turbines for more sustainable aircraft engines must meet strict limitations for soot particle mass and size distribution. Therefore, a comprehensive understanding of the processes leading to soot particle formation and its precise prediction in practical combustion systems is crucial. In this work, a recently developed detailed soot model, the Split-based Extended Quadrature Method of Moments (S-EQMOM), is applied to simulate a model aero-engine combustor, experimentally investigated by the German Aerospace Center (DLR). In previous studies, the S-EQMOM demonstrated good prediction capability in predicting soot particle oxidation, important to account for the reduction of soot particles. Here, the model is evaluated at elevated pressure conditions. Large eddy simulations are performed using flamelet-based tabulated chemistry with artificially thickened flame (ATF) approach coupled with the S-EQMOM. The simulation results are analyzed for both the gas phase and soot solid phase and compared with the experimental data. Velocity and temperature fields are well predicted. Soot formation is underestimated by the simulation, but qualitatively in good agreement with the experimental data.

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Section: Numerical Modeling a Combustion Modelmentioning

confidence: 99%

“…where the superscript T indicates the value obtained from the flamelet table. Numerical simulations are performed with an in-house solver developed into the OpenFOAM framework [6,36,42]. The burner and operating points are described in detail in [17][18][19][20].…”

Section: B Soot Modelmentioning

confidence: 99%

Soot Prediction in a Model Aero-Engine Combustor using a Quadrature-based Method of Moments

Cokuslu

Hasse

Geigle

et al. 2022

AIAA SCITECH 2022 Forum

Self Cite

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“…d𝜂 2 P(𝜂)d𝜂 convergence of the flow and combustion equations at each time step. A second-order central scheme is used for the velocity convective fluxes, which is not uncommon in reacting LES (see for example (Butz et al 2015;Zhang and Mastorakos 2017;Popp et al 2021;Yu et al 2020)) and was considered sufficient on the basis of the validation and mesh sensitivity analysis carried out in Barlow (2018) and Chen et al (2020). Although the use of higher order schemes is possible and could yield improved results Rochette et al 2018), this choice is known for causing instabilities in the flame region due to the strong gradients, unless grid resolution across the flame front approaches DNS requirements.…”

Section: Numerical Setupmentioning

confidence: 99%

Analysis of Flame Front Breaks Appearing in LES of Inhomogeneous Jet Flames Using Flamelets

Soli

Langella

Chen

2021

Flow Turbulence Combust

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The physical mechanism leading to flame local extinction remains a key issue to be further understood. An analysis of large eddy simulation (LES) data with presumed probability density function (PDF) based closure (Chen et al., 2020, Combust. Flame, vol. 212, pp. 415) indicated the presence of localised breaks of the flame front along the stoichiometric line. These observations and their relation to local quenching of burning fluid particles, together with the possible physical mechanisms and conditions allowing their appearance in LES with a simple flamelet model, are investigated in this work using a combined Lagrangian-Eulerian analysis. The Sidney/Sandia piloted jet flames with compositionally inhomogeneous inlet and increasing bulk speeds, amounting to respectively 70 and 90% of the experimental blow-off velocity, are used for this analysis. Passive flow tracers are first seeded in the inlet streams and tracked for their lifetime. The critical scenario observed in the Lagrangian analysis, i.e., burning particles crossing extinction holes on the stoichiometric iso-surface, is then investigated using the Eulerian control-volume approach. For the 70% blow-off case the observed flame front breaks/extinction holes are due to cold and inhomogeneous reactants that are cast onto the stoichiometric iso-surface by large vortices initiated in the jet/pilot shear layer. In this case an extinction hole forms only when the strain effect is accompanied by strong subgrid mixing. This mechanism is captured by the unstrained flamelets model due to the ability of the LES to resolve large-scale strain and considers the SGS mixture fraction variance weakening effect on the reaction rate through the flamelet manifold. Only at 90% blow-off speed the expected limitation of the underlying combustion model assumption become apparent, where the amount of local extinctions predicted by the LES is underestimated compared to the experiment. In this case flame front breaks are still observed in the LES and are caused by a stronger vortex/strain interaction yet without the aid of mixture fraction variance. The reasons for these different behaviours and their implications from a physical and modelling point of view are discussed in this study.

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“…The prediction of CO is challenging not only in the scope of FWI. Because the chemical timescales of CO are long, transport processes influence the oxidation of CO in unconstrained flows as well [14]. A promising approach is the solution of an additional transport equation for CO.…”

Section: Introductionmentioning

confidence: 99%

“…Trisjono et al [16] implemented a transport equation for NO with an enthalpy defect to account for heat loss. In recent years, this idea has been extended to CO chemistry by Han et al [17] and Popp et al [14]. Han et al compared results from finite rate chemistry to strained and unstrained flamelets and found that a table of several differently strained flamelets was necessary to accurately capture the flame structure.…”

Section: Introductionmentioning

confidence: 99%

Direct numerical simulation of flame-wall interaction at gas turbine relevant conditions

Niemietz

Berger

Huth

et al. 2023

Proceedings of the Combustion Institute

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Assessing multi-regime combustion in a novel burner configuration with large eddy simulations using tabulated chemistry

Cited by 24 publications

References 24 publications

Soot Prediction in a Model Aero-Engine Combustor using a Quadrature-based Method of Moments

Soot Prediction in a Model Aero-Engine Combustor using a Quadrature-based Method of Moments

Analysis of Flame Front Breaks Appearing in LES of Inhomogeneous Jet Flames Using Flamelets

Direct numerical simulation of flame-wall interaction at gas turbine relevant conditions

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