poster

edcSMOKE: A new OpenFAOM Combustion Solver Based on the
Eddy Dissipation Concept
A. Cuoci1, R. Malik2, A. Parente2
[email protected]
1.Department of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Italy
2. Aero-Thermo-Mechanical Departement, Université Libre de Bruxelles, Brussels, Belgium
Motivation
Numerical simulations of turbulent
flames (after 2005)
Number of species
The numerical modelling of turbulent combustion is a very challenging task as it combines the complex phenomena of turbulence and chemical reactions. This study
becomes even more challenging when large detailed kinetic mechanisms are used in order to understand some special features such as pollutant formation. Several
solvers have been proposed until now assuming global chemistry but detailed chemical schemes are required for the prediction of slow species (such as NOx).
The purpose of this work was to implement a new stable solver for OpenFOAM capable of using detailed chemical reaction mechanisms. The integration of detailed
chemistry is done with the Eddy Dissipation Concept (EDC) of Magnussen [1]. The new solver presented here has been developed in order to treat efficiently complex
kinetics when coupled with the EDC model.
The solver was developed both under the steady-state form (“edcSimpleSMOKE”) and the unsteady form (“edcPimpleSMOKE”). Moreover, the solver is coupled with
the OpenSMOKE library developed by Cuoci [2] and specially developed to manage large, detailed kinetic schemes (with hundreds of species and thousands of
reactions) in CFD simulations
Detailed kinetic schemes
RANS
LES
DNS
Complex CFD simulations
~ 100 species
~ 1000 reactions
millions of computational cells
Eddy Dissipation Concept
edcSMOKE Framework
• General model for turbulence chemistry interactions
• Allows to incorporate detailed kinetic schemes
• Main assumption: reactions occur in the fine structures and surroundings are inert
• Fine structures described as Perfectly Stirred Reactors (PSR)
OpenFOAM® Framework
Complex 2D/3D geometries
• unstructured meshes
• complex boundary conditions
• state of the art schemes for discretization
The reactive, turbulent flows under investigation in the present work are mathematically described by the
conservation equations for continuous, multi-component, compressible, thermally-perfect mixtures of gases.
The conservation equations of total mass, mixture momentum, individual species mass fractions and mixture
energy are solved for a Newtonian fluid in turbulent conditions. The density of the mixture is calculated
using the equation of state of ideal gases. Both Fickian and thermal diffusion (Soret effect) are taken into
account for evaluating the diffusion velocities.
Stiff ODE solvers
edcSMOKE
CFD code for turbulent reacting flows with
detailed kinetic mechanisms
• completely open-source
• easily extensible (object oriented design)
• efficiency and robustness
Figure 1 - Schematic of a computational cell based on EDC model
Numerical Libraries
Mean reaction rate for Navier-Stokes
equations
Bzz Math
• linear algebra
• nonlinear systems, ODE
Intel MKL
• linear solvers
• efficient mathematical operations
Set of non-linear algebraic equations
Ns : number of species in the mechanism
Flame details
Fuel: CO/H2/N2 (40%, 30%, 30% mass)
Air: O2/N2 (23.2%, 76.8% mass)
Temperature: 298 K
Pressure: 1 atm
Vfuel (flame A): 76 m/s
Vfuel (flame B): 45 m/s
Vair: 0.75 m/s
Reynolds number: 16,700
OpenSMOKE Framework
Complex Gas-Phase Chemistry
• homogeneous reactions
• detailed transport properties
• CHEMKIN compatible
• ~100 species, ~1000 reactions
• Sensitivity Analysis, ROPA, etc.
Name
Language
Linear system
solution
Code
available
Web address
BzzMath6
C++
Direct
No
http://homes.chem.polimi.it/gbuzzi/index.htm
DVODE
FORTRAN
Direct
Yes
https://computation.llnl.gov/casc/odepack/odepack_home.html
CVODE
C
Direct/Iterative
Yes
https://computation.llnl.gov/casc/sundials/main.html
DLSODE
FORTRAN
Direct
Yes
https://computation.llnl.gov/casc/odepack/odepack_home.html
DLSODA
FORTRAN
Direct
Yes
https://computation.llnl.gov/casc/odepack/odepack_home.html
RADAU5
FORTRAN
Direct
Yes
http://www.unige.ch/~hairer/software.html
LIMEX4
FORTRAN
Direct
Yes
http://www.zib.de/en/numerik/software/codelib
MEBDF
FORTRAN
Direct
Yes
http://www2.imperial.ac.uk/~jcash/IVP_software
The code is specifically conceived for managing complex kinetic
mechanisms and detailed transport properties in CHEMKIN format
Syngas flames
Methane flame
Sandia/ETH-Zurich CO/H2/N2 Jet Flames
Sandia/TUD Piloted CH4/Air Jet Flame D
Geometry
Flame A
Fuel nozzle inner diameter: 4.58 mm
outer diameter: 6.34 mm
Flame B
Fuel nozzle inner diameter: 7.72 mm
outer diameter: 9.46 mm
Flame details
Fuel: CH4/Air (25%, 75% mass)
Pilot: mixture of C2H2/H2 /air/CO2 /N2
Temperature: 294 K
Pressure: 1 atm
Vfuel: 49.6 m/s
Vair: 0.9 m/s
Reynolds number: 22,400
Polimi COH2 kinetic scheme
32 species
178 reactions
Freely available in CHEMKIN format at:
http://creckmodeling.chem.polimi.it/
Computational details
Domain: 3D axisymmetric (75 x 600 mm)
Computational grid: ~5,000 cells
Geometry
Fuel nozzle diameter: 7.2 mm
Coflow diameter: 18.2 mm
Numerical predictions
Computational details
Domain: 3D axisymmetric (150 x 650 mm)
Computational grid: ~4600 cells
Flame B
Flame A
Kinetic schemes
GRI30: 53 species, 325 reactions
PolimiC1C3HTNOX: 114 species, 2,105 reactions
Figure 8 – Temperature, CH4 and OH fields for flame D
Figure 2 – Temperature, H2 and CO fields for flame A
Figure 3 – Temperature, H2 and CO fields for flame B
Comparison with experimental data
Comparison with experimental data
Figure 4 – Temperature profile
Figure 5 – NO profile
Figure 6 – Temperature profile
Figure 7 – NO profile
References
[1] Gran IR, Magnussen BF., Comb. Sci. Tech 1996;119:191-217.
[2] A. Cuoci, A. Frassoldati, T. Faravelli, E. Ranzi. OpenSMOKE: Numerical modeling of reacting
systems with detailed kinetic mechanisms. XXXIV Meeting of the Italian Section of
the Combustion Institute.
[3] Barlow, R. S., Fiechtner, G. J., Carter, C. D., Chen, J.-Y., "Experiments on the Scalar Structure
of Turbulent CO/H2/N2 Jet Flames," Combust. and Flame 120:549-569 (2000).
Figure 9 – O2 profile
Figure 10 – O2 profile
Figure 11 – Temperature profiles
[4] Smith GP, Golden DM et al. GRI 3.0. http://www.me.berkeley.edu/gri_mech/
[5] A. Cuoci, A. Frassoldati, G. Buzzi Ferraris, T. Faravelli, E. Ranzi. International Journal of Hydrogen Energy, 32: 3486-3500 (2007).
[6] A. Cuoci, A. Frassoldati, T. Faravelli, E. Ranzi. Combustion and Flame 156 (10), pp. 2010-2022 (2009).

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