Scalar-Filtered Mass-Density-Function Simulation of Swirling Reacting Flows on Unstructured Grids

AIAA Journal ◽  
2012 ◽  
Vol 50 (11) ◽  
pp. 2476-2482 ◽  
Author(s):  
N. Ansari ◽  
P. H. Pisciuneri ◽  
P. A. Strakey ◽  
P. Givi
Keyword(s):  
Density Function ◽  
Unstructured Grids ◽  
Mass Density ◽  
Reacting Flows ◽  
Filtered Mass Density Function

Two-phase filtered mass density function for LES of turbulent reacting flows

2014 ◽  
Vol 760 ◽  
pp. 243-277 ◽  
Author(s):  
Z. Li ◽  
A. Banaeizadeh ◽  
F. A. Jaberi
Keyword(s):  
Density Function ◽  
Stokes Equations ◽  
Liquid Droplet ◽  
Mass Density ◽  
Mixing Layer ◽  
Reacting Flows ◽  
Navier Stokes ◽  
Turbulent Reacting Flows ◽  
Two Phase ◽  
Filtered Mass Density Function

AbstractThis paper describes a new computational model developed based on the filtered mass density function (FMDF) for large-eddy simulation (LES) of two-phase turbulent reacting flows. The model is implemented with a unique Lagrangian–Eulerian–Lagrangian computational methodology. In this methodology, the resolved carrier gas velocity field is obtained by solving the filtered form of the compressible Navier–Stokes equations with high-order finite difference (FD) schemes. The gas scalar (temperature and species mass fractions) field and the liquid (droplet) phase are both obtained by Lagrangian methods. The two-way interactions between the phases and all the Eulerian and Lagrangian fields are included in the new two-phase LES/FMDF methodology. The results generated by LES/FMDF are compared with direct numerical simulation (DNS) data for a spatially developing non-reacting and reacting evaporating mixing layer. Results for two more complex and practical flows (a dump combustor and a double-swirl burner) are also considered. For all flows, it is shown that the two-phase LES/FMDF results are consistent and accurate.

Filtered mass density function for large-eddy simulation of turbulent reacting flows

1999 ◽  
Vol 401 ◽  
pp. 85-121 ◽  
Author(s):  
F. A. JABERI ◽  
P. J. COLUCCI ◽  
S. JAMES ◽  
P. GIVI ◽  
S. B. POPE
Keyword(s):  
Monte Carlo ◽  
Large Eddy Simulation ◽  
Transport Equation ◽  
Density Function ◽  
Shear Flows ◽  
Mass Density ◽  
Reacting Flows ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Filtered Mass Density Function

A methodology termed the ‘filtered mass density function’ (FMDF) is developed and implemented for large-eddy simulation (LES) of variable-density chemically reacting turbulent flows at low Mach numbers. This methodology is based on the extension of the ‘filtered density function’ (FDF) scheme recently proposed by Colucci et al. (1998) for LES of constant-density reacting flows. The FMDF represents the joint probability density function of the subgrid-scale (SGS) scalar quantities and is obtained by solution of its modelled transport equation. In this equation, the effect of chemical reactions appears in a closed form and the influences of SGS mixing and convection are modelled. The stochastic differential equations (SDEs) which yield statistically equivalent results to those of the FMDF transport equation are derived and are solved via a Lagrangian Monte Carlo scheme. The consistency, convergence, and accuracy of the FMDF and the Monte Carlo solution of its equivalent SDEs are assessed. In non-reacting flows, it is shown that the filtered results via the FMDF agree well with those obtained by the ‘conventional’ LES in which the finite difference solution of the transport equations of these filtered quantities is obtained. The advantage of the FMDF is demonstrated in LES of reacting shear flows with non-premixed reactants. The FMDF results are appraised by comparisons with data generated by direct numerical simulation (DNS) and with experimental measurements. In the absence of a closure for the SGS scalar correlations, the results based on the conventional LES are significantly different from those obtained by DNS. The FMDF results show a closer agreement with DNS. These results also agree favourably with laboratory data of exothermic reacting turbulent shear flows, and portray several of the features observed experimentally.

A Hybrid Large Eddy Simulation/Filtered Mass Density Function for the Calculation of Strongly Radiating Turbulent Flames

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Abhilash J. Chandy ◽  
David J. Glaze ◽  
Steven H. Frankel
Keyword(s):  
Density Function ◽  
Soot Formation ◽  
Mass Density ◽  
Combustion Products ◽  
Turbulent Flames ◽  
Finite Rate ◽  
Combustion Chemistry ◽  
Jet Flame ◽  
Large Eddy ◽  
Filtered Mass Density Function

Due to the complex nonlinear coupling of turbulent flow, finite-rate combustion chemistry and thermal radiation from combustion products and soot, modeling, and/or simulation of practical combustors, or even laboratory flames undergoing strong soot formation, remain elusive. Methods based on the determination of the probability density function of the joint thermochemical scalar variables offer a promising approach for handling turbulence-chemistry-radiation interactions in flames. Over the past decade, the development and application of the filtered mass density function (FMDF) approach in the context of large eddy simulations (LES) of turbulent flames have gained considerable ground. The work described here represents the first application of the LES/FMDF approach to flames involving soot formation and luminous radiation. The initial focus here is on the use of a flamelet soot model in an idealized strongly radiating turbulent jet flame, which serves to detail the formulation, highlight the importance of turbulence-radiation interactions, and pave the way for the inclusion of a soot transport and finite-rate kinetics model allowing for quantitative comparisons to laboratory scale sooting flames in the near future.

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