Differential diffusion in binary scalar mixing and reaction

Jaberi, Farhad; Miller, Richard S.; Mashayek, Farzad; Givi, Peyman

doi:10.1016/s0010-2180(97)00045-x

Cited by 26 publications

(12 citation statements)

References 29 publications

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“…• Extension of the FDF methodology to account for differential diffusion effects. [55][56][57][58][59][60][61] The FVS-FMDF may be extended to flows with nonunity Prandtl and/or Schmidt numbers. It may also be extended to include temperature dependent viscosity and diffusion coefficients.…”

Section: -11mentioning

confidence: 99%

Frequency-velocity-scalar filtered mass density function for large eddy simulation of turbulent flows

2009

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A methodology termed "frequency-velocity-scalar filtered mass density function" ͑FVS-FMDF͒ is developed for large eddy simulation ͑LES͒ of turbulent flows. The FVS-FMDF takes account of unresolved subgrid scales ͑SGSs͒ by considering the joint probability density function ͑PDF͒ of the frequency, the velocity, and the scalar fields. An exact transport equation is derived for the FVS-FMDF in which the effects of convection and chemical reaction are in closed forms. The unclosed terms in this equation are modeled in a fashion similar to PDF methods in Reynolds-averaged Navier-Stokes simulations. The FVS-FMDF transport is modeled via a set of stochastic differential equations ͑SDEs͒. The numerical solution procedure is based on a hybrid finite-difference ͑FD͒/Monte Carlo ͑MC͒ method in which the LES filtered transport equations are solved by the FD, and the set of SDEs is solved by a Lagrangian MC procedure. LES of a temporally developing mixing layer is conducted via the FVS-FMDF, and the results are compared with those via the Smagorinsky SGS closure. All these results are also assessed by comparison with those obtained by direct numerical simulation ͑DNS͒. The FVS-FMDF predictions show favorable agreements with DNS data.

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Section: -11mentioning

confidence: 99%

Frequency-velocity-scalar filtered mass density function for large eddy simulation of turbulent flows

2009

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“…neglected diffusion phenomena are necessary to accurately capture the physics of the combustion process; particularly at high pressure. [6][7][8][9][10][11][12][13][14][15][16] Numerical techniques have proven themselves to be a useful tool in studying a large number of flows, including those involving combustion. If sufficient computational resources are available, all spatial and temporal scales of the desired flow can be directly calculated.…”

Section: Introductionmentioning

confidence: 99%

A priori analysis of subgrid mass diffusion vectors in high pressure turbulent hydrogen/oxygen reacting shear layer flames

Foster

Miller

2012

Physics of Fluids

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Evaluation of an unsteady flamelet progress variable model for autoignition and flame development in compositionally stratified mixtures Phys. Fluids 24, 075115 (2012) Intermittency in premixed turbulent reacting flows Phys. Fluids 24, 075111 (2012) Recirculation zone dynamics of a transversely excited swirl flow and flame Phys. Fluids 24, 075107 (2012) Short-term prediction of dynamical behavior of flame front instability induced by radiative heat loss Chaos 22, 033106 (2012) Route to chaos for combustion instability in ducted laminar premixed flames Chaos 22, 023129 (2012) Additional information on Phys. Fluids Direct numerical simulations of high pressure (100 atm), turbulent H 2 /O 2 nonpremixed temporally developing shear layer flames are conducted at initial Reynolds numbers ranging from 850 ≥ Re δ0 ≥ 4500, with up to ∼3/4 ×10 9 grid points. A real gas equation of state, real property models, detailed chemistry, and generalized diffusion models are included. The results of the simulations focus on the mass diffusion vectors and their subgrid contributions relevant to large eddy simulation of turbulent combustion. Comparisons of the actual filtered mass flux vectors with their corresponding forms evaluated with filtered primitive variables are shown through correlation coefficients, probability density functions (PDFs) of the ratios between the vector magnitudes, and PDFs of the angles between the vectors. The results show a reasonable correlation (≥0.75) for all species and simulations when evaluated globally. However, the correlations weaken substantially in regions of large temperature subgrid scale (SGS) variance and filtered SGS scalar dissipation. Within these regions, the correlations are also shown to vary inversely with Reynolds number. Vector analysis indicates that evaluating the mass flux vector using only the filtered primitive variables accurately predicts the direction of the actual filtered flux; however, the magnitude is poorly predicted in the aforementioned regions. Comparisons of the subgrid mass fluxes to the subgrid scalar fluxes are also represented as PDFs of the ratios between the vector magnitudes. These results show the subgrid mass flux to be significantly smaller ( 5%) than the subgrid scalar flux, and this ratio is shown to diminish with increasing Reynolds number. A final comparison of the divergence of the subgrid mass fluxes to the subgrid scalar fluxes are also represented as PDFs of the ratios between the magnitudes. At lower Reynolds numbers, these ratios suggest comparable values between the subgrid diffusion and turbulent stirring terms in regions of large temperature SGS variance and filtered SGS scalar dissipation. However, this ratio is shown to diminish, but remain significant, with increasing Reynolds number. C 2012 American Institute of Physics. [http://dx.

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“…• Extension of the FDF methodology for flows with differential diffusion effects [51,58,68,84,111,124].…”

Section: Summary and Prospectsmentioning

confidence: 99%

Developments in Formulation and Application of the Filtered Density Function

Drozda

Sheikhi

Madnia

et al. 2006

Flow Turbulence Combust

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An overview is presented of the state of progress in large eddy simulation of turbulent combustion via the filtered density function (FDF). This includes the formulations based on both the joint velocity-scalar FDF, and the marginal scalar FDF. In the former, the most up-to-date and comprehensive form of the model is presented along with its applications for LES of some relatively simple flows. In the latter, results are presented of the most recent LES of a complex turbulent flame. Both of the models are described in the context of a variable density flow via consideration of the filtered mass density function (FMDF).

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Differential diffusion in binary scalar mixing and reaction

Cited by 26 publications

References 29 publications

Frequency-velocity-scalar filtered mass density function for large eddy simulation of turbulent flows

Frequency-velocity-scalar filtered mass density function for large eddy simulation of turbulent flows

A priori analysis of subgrid mass diffusion vectors in high pressure turbulent hydrogen/oxygen reacting shear layer flames

Developments in Formulation and Application of the Filtered Density Function

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