Turbulent swirling flames: Experimental investigation of the flow field and formation of nitrogen oxide

Schmittel, Peter; Günther, Bert; Lenze, B.; Leuckel, Wolfgang; Bockhorn, Henning

doi:10.1016/s0082-0784(00)80224-6

Cited by 54 publications

(37 citation statements)

References 5 publications

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“…In combustion systems, IRZ serves as a reservoir of heat and radicals that re-ignite the reactant mixture and thereby stabilize the ame. IRZ a ects the ame shape, ame stability and heat release rate, as well as emission of nitrogen oxide [8]. Development and improvement of modern gas turbine combustion chambers demand a deeper understanding of the fundamental physics and appropriate numerical simulations of turbulent swirling ows.…”

Section: Introductionmentioning

confidence: 99%

Large eddy simulations of turbulent swirling flows in a dump combustor: a sensitivity study

Wang¹,

Bai²

2004

Int. J. Numer. Meth. Fluids

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SUMMARYLarge eddy simulations (LES) of conÿned turbulent swirling ows in a model dump combustor are carried out. The simulations are based on a high-order ÿnite di erence method on a Cartesian grid, with the sub-grid scale stress tensor modelled using a scale-similarity model. The aims of this work are to study the physics of the ow and to evaluate the performance of LES method for simulation of the major features of turbulent swirling ows-the vortex breakdown, the highly anisotropic and fast-decaying turbulence structure. In uences of in ow=out ow conditions, combustor geometry, inlet swirl proÿle and Reynolds numbers on the vortex breakdown and turbulence structures are investigated. At very high swirl levels, the in uence of the out ow conditions and the outlet geometry is fairly signiÿcant, not only at downstream near the outlet, but also at far upstream. At low Reynolds numbers, the onset of vortex breakdown is fairly sensitive to the change of Reynolds number; however, at high Reynolds numbers it is rather insensitive to the Reynolds number. Comparisons of LES results with experimental data are made. The LES results are shown to be in reasonably good agreement with the experimental data if appropriate in ow and out ow boundary conditions are imposed.

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Section: Introductionmentioning

confidence: 99%

Large eddy simulations of turbulent swirling flows in a dump combustor: a sensitivity study

Wang¹,

Bai²

2004

Int. J. Numer. Meth. Fluids

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“…The non-reactive flow in the TECFLAM / TYPE II combustor was experimentally investigated by means of LDA in [8]. The configuration consists of an annular swirling jet entering a cylindrical combustion chamber.…”

Section: Results For the Flow In A Model Combustormentioning

confidence: 99%

Wavelet-Adapted Sub-grid Scale Models for LES

Denev

Falconi

Fröhlich

et al. 2010

Notes on Numerical Fluid Mechanics and Multidisciplinary Design

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The paper presents two novel turbulent models for LES based on a wavelet decomposition. This approach, denoted WALES, is simple and easy to implement. Tests on a number of flows using grids with different resolution near walls show that the models exhibit the same quality as the Smagorinsky model without the need of wall functions or near-wall damping. In the paper the basic wavelet framework and two such models are described in detail. Physical benefits of the models due to the use of wavelets are discussed. Results obtained with the models are compared to those using the Smagorinsky model, to experimental results and to results from Direct Numerical Simulations. The agreement achieved is generally good.

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“…The injector is moved vertically within the chamber like a piston (up to 500 mm) in order to change the axial-plane of measurement 12,13 . The axial symmetry of the flame has been previously reported as being "experimentally checked and confirmed" 14,15 .…”

Section: Descriptionmentioning

confidence: 99%

“…Figure 7 of reference 13 . The NOx contour plot presented in Figure 18 compares satisfactorily with the experimental data presented in reference 13 . Rates of production in kg m -3 s -1 of NO, NO2, NOx, N2O and HCN predicted by CFD-CRN are shown in Figure 19.…”

Section: Formation Of Co and Noxmentioning

confidence: 99%

Detailed Emissions Prediction for a Turbulent Swirling Nonpremixed Flame

et al. 2014

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This paper describes validation of a previously-described CFD-CRN method (computational fluid dynamics -chemical reactor network) for emissions predictions for the laboratory benchmark TECFLAM S09c flame. It details CFD simulation, solution strategy, validation using, CRN generation, detailed emissions predictions and reaction pathway studies. Steady-state 3D CFD models of a 45° † Corresponding author. Email address: rory.monaghan@nuigalway.ie. Tel: +353(91)494-256. 2 sector of the combustor, employing standard numerical techniques; steady-state k- SST turbulence, P1 radiation, finite-rate eddy-dissipation turbulence-chemistry interaction, and three-step methane combustion mechanism, were created in ANSYS FLUENT v14. Steady-state models were used as they are of interest to industrial researchers, who are often limited to their use by extremely complex geometries. The models differ in their handling of pressure-velocity coupling and discretization of the momentum equation. The solution which uses SIMPLE coupling and second-order upwind discretization of the momentum equation was generally found to give better results. Satisfactory agreement with experimental profiles for velocity, turbulent kinetic energy, temperature, and species mass fractions has been achieved. Some errors are seen in temperature and CO mass fractions at the highest temperatures (T > 2000 K) and are due to the fact that the highly-simplified three-step kinetic mechanism employed due to practical limitations on computational resources, underestimates CO2 dissociation. The results compare satisfactorily with the state-of-the-art. Non-zero concentrations of CO are predicted in the external recirculation zone, which has not been achieved in previous modeling efforts. The validated solution was used as the basis to generate a CRN using the CFD-CRN method.The CFD-CRN method uses user-defined criteria to divide the CFD domain into a set of interconnected perfectly-stirred reactors (PSRs), i.e. a CRN. This CRN is then solved using detailed chemical kinetic mechanisms in the Kinetic Post-Processor (KPPSMOKE) solver. CRN size-independence studies are performed and it is determined that 5000+ PSRs were needed to adequately capture pollutant formation in the complex recirculating flow field. Validation of CFD-CRN predictions of major species show similar accuracy to steady-state CFD simulation, with improvements over state-of-the-art CFD in CO profile predictions. Satisfactory agreement with previously-published experimental NOx contour plots is also seen. The CFD-CRN is used to study NOx formation pathways in the swirling, turbulent environment of the S09c diffusion flame. As expected, NOx is seen to form primarily in the hightemperature internal recirculation zone (IRZ). The prompt pathway is predicted to be of greatest importance in this area. Significant NOx reburning is seen in the low temperature fuel-air jets 3 immediately adjacent to the IRZ. Overall, the prompt pathway is responsible for 77% of NOx leaving the system, with 12% due to the...

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Turbulent swirling flames: Experimental investigation of the flow field and formation of nitrogen oxide

Cited by 54 publications

References 5 publications

Large eddy simulations of turbulent swirling flows in a dump combustor: a sensitivity study

Large eddy simulations of turbulent swirling flows in a dump combustor: a sensitivity study

Wavelet-Adapted Sub-grid Scale Models for LES

Detailed Emissions Prediction for a Turbulent Swirling Nonpremixed Flame

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