Advancing turbulent combustion modeling using the · PDF fileAdvancing turbulent combustion...

Advancing turbulent combustion modeling using the Eddy Dissipation Concept with detailed chemistry

Dmitry Lysenko1, Ivar Ertesvåg1 Kjell Eric Rian2

1Norwegian University of Science and Technology, Trondheim, Norway 2Computational Industry Technologies, Trondheim, Norway

OSCIC’13, Hamburg, Germany, October 24-25, 2013

Agenda

• Motivation & background • Turbulent combustion modeling

• Multi-scales and multi-physics • Maths and numerics • HPC

• Results • Sandia flame CHNa • Sydney bluff-body flame HM1E • Sandia flame D

• Summary


Motivation & background (I)

• Advancing the numerical modeling of interactions between turbulent flow and chemical kinetics for Large-eddy simulation • The Eddy Dissipation Concept (EDC) has been developed by Bjørn F. Magnussen and co-workers at NTNU/SINTEF over nearly four decades

o Eddy Dissipation Model / Magnussen and Hjertager (1976) o Eddy Dissipation Concept / Gran and Magnussen (1996) Ertesvåg and

Magnussen (2000), Lilleberg et al. (2013) • EDM (EDC) has become the standard model almost in all commercial CFD codes • Although considerable success, there is still potential for further development ☺ • Continues evaluation of the previous efforts resulted in PhD studies by Panjwani (NTNU), Lilleberg (NTNU) and Christ (RWTH Aachen University) • The main emphasis is development of the compressible RAS/LES solver for turbulent combustion simulations using EDC with detailed chemistry


Motivation & background (II) • Previously, the excessive validation was carried out for the turbulent flows using

RANS/LES approaches:

o Modeling of turbulent separated flows using OpenFOAM // Comput. Fluids, 80, 408-422 (2013) o Large-Eddy Simulation of the Flow Over a Circular Cylinder at Reynolds Number 3900 Using

the OpenFOAM Toolbox // Flow Turbulence Combustion (2012) 89:491-518 o Large-eddy simulation of the flow over a circular cylinder at Reynolds number 20000 // Flow,

Turbulence Combustion, DOI 10.1007/s10494-013-9509-1 o Towards simulation of far-field aerodynamic sound from a circular cylinder using OpenFOAM //

submitted to special issue of Int J AeroAcoustics / proceedings of the seminar Computational Experiment in AeroAcoustics (2012)

o Numerical simulation of turbulent flames using the Eddy Dissipation Concept with detailed chemistry, In: Skallerud B., Andersson H.I., editors. Computational mechanics, Trondheim, p.159-178 (2013)


Turbulent combustion modeling


• Heat and mass transfer • Turbulence • Unsteady combustion physics • Radiation • Steam injection • Gaseous/Liquid fuels • Emissions (NOx, CO, soot) • Thermo-acoustics (dynamics)

Turbulent combustion modeling (I) Multi-scales and multi-physics

Classifications of time scales in a chemically reacting flow (Warnatz 2006)

Sandia Flame D

Heavy-duty gas turbine GTE-150 (LMZ/Power Machines)


Turbulent combustion modeling (II) Mathematical modeling

Fine structures:

Results from recent DNS of combustion at moderate Re and Da numbers from Tanahashi, Sato, Shimura, Miyauchi, J. Therm. Sci. Technol (2008). Iso-surfaces of the heat-release (yellow) and vorticity (gray) from a planar flame in homogeneous isotropic turbulence at Re = 515, Da= 21, and Ka =1.3

EDC for reaction rates:

Transport equation for the mean mass fraction of an individual species Ys:

Perfectly Stirred Reactor (PSR) concept


ωs* - reaction rate from chemical kinetics

mechanism;

τ* - reactor residence time (mixing time scale)

Spatial discretization

• FVM based on PISO algorithm • URANS - 2nd order upwind (linearUpwind) scheme for viscous terms • Reacting LES – Gamma (CDS-2/NVD) for momentum; linearLimited (TVD) for scalars

Temporal discretization • 2nd order implicit backward Euler method (BDF-2) • Dynamic adjustable time stepping (CFL<0.4)

Linear algebra and accuracy • ICCG (1x10-7)/Gauss-Seidel smoother (1x10-7)

Turbulence • Compressible URANS with the family of k-ε (k-ω) models • Compressible LES with k-equation eddy-viscosity SGS model (Yoshizawa , 1986), sub-grid

scale incompressibility hypothesis Turbulence-chemistry interaction

• Eddy-Dissipation Concept ODE for chemistry integration

• Implicit RK5 method (RADAU5) with abs tolerance of 10-6

Thermodynamics • Ideal gas

Turbulent combustion modeling (III) Numerics


Turbulent combustion modeling (IV) High Performance Computing

VILJE@NTNU SGI Altix 8600 cluster

Number of nodes 1440

Number of cores 23040

CPU type Intel Sandy Bridge

Cores/node 2x8

Memory/node 32 Gb

Network FDR Infiniband

OpenFOAM parallel performance. Strong scalability studies for 2D and 3D non-reacting (a,b) flows over a circular cylinder and for 2D and 3D reacting simulations of the Sandia Flame D (c,d) as function of number of nodes (a,c) and total number of cores (b,d), respectively. The

grid size is shown in brackets for each case. One node has 16 cores


Results • International Workshop on Measurements and Computations of Turbulent

Flames [http://www.sandia.gov] is an excellent example of the successful interrelationship between theoreticians, modelers, and laser diagnosticians for the development and validation of combustion models

• Outstanding example of the sort of validation experiments that are needed for the project goals and objectives


Results (I) - Sandia Flame CHNa Dimensions: Nozzle inner diameter, d = 4.58 mm; Outer diameter = 6.34 mm; Ujet = 76 m/s, Uco-flow = 0.75 m/s Fuel composition: 40% CO, 30% H2, 30% N2 (by volume) Reynolds jet number: 16,700 Scalar Measurements: Simultaneous Raman/Rayleigh/LIF measurements of T, N2, O2, CO2, H2O, H2, CO, OH, and NO were obtained with a spatial resolution of 0.75 mm. Velocity Measurements: Three-component LDV measurements References: 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)

Details of the grid near the inlet (a) and a general view of the computational domain (b) for the Sandia CHNa flame; 20 iso-contours of mean temperature (c) in a range of 400-2100 K


• Sandia Flame CHNa • Syngas combustion

40%CO,30%H2,30%N2 • Compressible URANS, standard k-ε model • Turbulence-chemistry interaction: EDC,

assumed β-PDF • Chemistry: FFR (14 species/34 reactions,

Frassoldati, Faravelli, Ranzi 2007); GRI3.0 (53 species/325 reactions, Bowman et al. 2008)

• P1 radiation

Mean temperature and mean composition profiles along the axis for the Sandia flame CHNa

Scatter plots of mixture fraction at different downstream positions for the Sandia flame CHNa: x/d = 20 (a) and x/d = 40 (b)

a b

Results (II) – Sandia Flame CHNa


Results (III) - Sydney Bluff-Body Flame HM1E

Dimensions: Bluff-Body (DB = 50 mm body, 3.6 mm jet) Ujet = 108m/s, Uco-flow = 35m/s, 50% blowoff Fuel: CNG/H2 (1/1); Reynolds jet number: 15,800 Velocity measurements: Laser Doppler velocimetry (LDV), Scalar measurements: Raman/Rayleigh/LIF techniques References: Dally, B.B., Masri, A.R., Barlow, R.S. and Fiechtner, G.J., Instantaneous and mean compositional structure of bluff- body stabilised nonpremixed flames. Combust. Flame, 114, 119-148 (1998)

General view of the computational domain (a) and details of the grid near the inlet (b) and for the Sydney bluff-body HM1E flame; 20 iso-contours of mean temperature (c) in a range of 400-2100 K


x/DB = 0.2

x/DB = 0.4

Results (IV) – Sydney Bluff-Body Flame HM1E

Radial profiles of the mean axial (a) and radial (b) velocity for the Sydney bluff-body flame HM1E

Time-averaged streamlines for the Sydney bluff-body flame HM1E

• Sydney Flame HM1E; Main jet CH4/H2 (1:1) • Compressible URANS, standard k-ε model • Turbulence-chemistry interaction: EDC • Chemistry: GRI-3.0 (53 species/325 reactions) • P1 radiation


x/DB = 0.8

a b

• Sydney Flame HM1E; Main jet CH4/H2 (1:1) • Compressible URANS, standard k-ε model • Turbulence-chemistry interaction: EDC • Chemistry: GRI-3.0 (53 species/325 reactions) • P1 radiation

Radial profiles of mean temperature and mean composition at x/DB=0.6 for the Sydney flame HM1E

Time-averaged streamlines for the Sydney bluff-body flame HM1E

x/DB = 0.6

Results (V) – Sydney Bluff-Body Flame HM1E


Dimensions: Nozzle diameter, d = 7.2 mm; Pilot diameter = 18.2 mm Main jet: 25% CH4, 75% air; Reynolds jet number: 22,400 Pilot: The pilot flame burns a premixture of C2H2, H2, air, CO2, and N2 having nominally the same equilibrium composition and enthalpy as CH4/air. The pilot is operated lean, φ = 0.77 Velocity Measurements: Two-component LDV measurements Scalar Measurements: Raman/Rayleigh/LIF measurements of F, T, N2, O2, CH4, CO2, H2O, H2, CO, OH, and NO were obtained with a spatial resolution of 0.75 mm References Barlow, R. S. and Frank, J. H., Proc. Combust. Inst. 27:1087-1095 (1998) Barlow, R. S., Frank, J. H., A. N. Karpetis, and Chen, J.-Y., "Piloted Methane/Air Jet Flames: Scalar Structure and Transport Effects," Combust. Flame 143:433-449 (2005). Schneider, Ch., Dreizler, A., Janicka, J., "Flow Field Measurements of Stable and Locally Extinguishing Hydrocarbon-Fuelled Jet Flames," Combust. Flame 135:185-190 (2003).

Results (VI) – Sandia Flame D


• Sandia Flame D • Compressible URANS • Standard k-ε model • Turbulence-chemistry interaction: EDC,

assumed β-PDF • Chemistry: GRI-3.0 (53 species/325 reactions)

and several reduced schemes • P1 radiation

Mean temperature and mean composition profiles along the axis for the Sandia flame D

Details of the grid near the inlet (a) and a general view of the computational domain (b) for the Sandia flame D; 20 iso-contours of mean temperature (c) in a range of 400-2000 K

Results (VII) – Sandia Flame D


• Sandia Flame D • Compressible LES • Convective schemes: Blended CDC-

2/NVD for momentum, TVD for other scalars

• Time integration: BDF-2 • One-equation eddy-viscosity SGS

model • Turbulence-chemistry interaction: EDC

Chemistry: single-step and DRM22 (22 species and 105 reactions)

• P1 radiation • Two grids: A1-240×60×90 and A2-

480×80×80

Instantaneous iso-surfaces of temperature (a) and λ2 (b) obtained by LES-A1 for the Sandia flame D

Results (VIII) – Sandia Flame D

Details of the LES-A2 grid: general view of the computational domain (a) and zoom of the grid near the inlet in x-r (b) and x-ϴ (c) planes and general scheme (d) for the Sandia Flame D: ϴ is the circumferential coordinate, x and r are the domain coordinates in stream-wise and radial directions


Results (IX) – Sandia Flame D

Fourier power spectra (WPD) and wavelet coefficient energy (CWT) with its associated scalogram of the axial velocity at x/d = 20 obtained by LES-A2 for the Sandia flame D

Mean temperature and composition as well as its fluctuations along the axis for the Sandia flame D

Potential limitations: • Fixed Inlet profiles/dilatation effects (Hossain

2001) • Simple turbulent inlet BCs • Grid resolution

Mean axial velocity (a) and its fluctuations (b) along the axis for the Sandia flame D


Summary

• The Eddy Dissipation Concept with detailed chemistry approach was implemented for compressible RAS and LES • Excessive validation was carried out for reacting URANS calculations, which demonstrate good match with the experimental data. It is believed that one of the main reasons for the observed discrepancies between the predictions and experimental data is the round-jet anomaly of the k-ε (ω) turbulence models • In future, one of the natural extension of EDC could be coupling with Scale-Adaptive Simulation (SAS) or Detached-Eddy Simulation (DES) • EDC-LES for Sandia flame D demonstrated very promising results in spite of some OpenFOAM limitations. However, more validation is required, especially for premixed flames


Acknowledgements

• This work was conducted as a part of the CenBio Center for environmentally-friendly energy

• We are very appreciated to the Norwegian Meta Center for Computational Science (NOTUR) for providing the uninterrupted HPC computational resources and the useful technical support

OSCIS’13, Hamburg, Germany, October 24-25, 2013

Advancing turbulent combustion modeling using the · PDF fileAdvancing turbulent combustion...

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