Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-18T21:46:02.341Z Has data issue: false hasContentIssue false

Direct numerical simulation of H2/O2/N2 flames with complex chemistry in two-dimensional turbulent flows

Published online by Cambridge University Press:  26 April 2006

M. Baum
Affiliation:
Laboratoire EM2C, CNRS, Ecole Centrale, Paris
T. J. Poinsot
Affiliation:
Centre de Recherche sur la Combustion Turbulente and IMFT/CERFACS, 42 av. G. Coriolis, 31057 Toulouse, France
D. C. Haworth
Affiliation:
General Motors NAO Research and Development Center, Warren, MI 48090, USA
N. Darabiha
Affiliation:
Laboratoire EM2C, CNRS, Ecole Centrale, Paris

Abstract

Premixed H2/O2/N2 flames propagating in two-dimensional turbulence have been studied using direct numerical simulations (DNS: simulations in which all fluid and thermochemical scales are fully resolved). Simulations include realistic chemical kinetics and molecular transport over a range of equivalence ratios Φ (Φ = 0.35, 0.5, 0.7, 1.0, 1.3). The validity of the flamelet assumption for premixed turbulent flames is checked by comparing DNS data and results obtained for steady strained premixed flames with the same chemistry (flamelet ‘library’). This comparison shows that flamelet libraries overestimate the influence of stretch on flame structure. Results are also compared with earlier zero-chemistry (flame sheet) and one-step chemistry simulations. Consistent with the simpler models, the turbulent flame with realistic chemistry aligns preferentially with extensive strain rates in the tangent plane and flame curvature probability density functions are close to symmetric with near-zero means. For very lean flames it is also found that the local flame structure correlates with curvature as predicted by DNS based on simple chemistry. However, for richer flames, by contrast to simple-chemistry results with non-unity Lewis numbers (ratio of thermal to species diffusivity), local flame structure does not correlate with curvature but rather with tangential strain rate. Turbulent straining results in substantial thinning of the flame relative to the steady unstrained laminar case. Heat-release and H2O2 contours remain thin and connected (‘flamelet-like’) while species including H-atom and OH are more diffuse. Peak OH concentration occurs well behind the peak heat-release zone when the flame temperature is high (of the order of 2800 K). For cooler and leaner flames (about 1600 K and for an equivalence ratio below 0.5) the OH radical is concentrated near the reaction zone and the maximum OH level provides an estimate of the local flamelet speed as assumed by Becker et al. (1990).

Type
Research Article
Copyright
© 1994 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ashurst, W. T. 1990 Geometry of premixed flames in three-dimensional turbulence. In Proc. 1990 Summer Program, pp. 245253. Center for Turbulence Research, Stanford University and NASA Ames
Ashurst, W. T. & Barr, P. K. 1983 Stochastic calculation of laminar wrinkled flame propagation via vortex dynamics. Combust. Sci. Technol. 34, 227256.Google Scholar
Ashurst, W. T., Peters, N. & Smooke, M. D. 1987 Numerical simulation of turbulent flame structure with non-unity Lewis number. Combust. Sci. Technol. 53, 339375.Google Scholar
Ashurst, W. T., Shivashinsky, G. I. & Yakhot, V. 1988 Flame-front propagation in non-steady hydrodynamic fields. Combust. Sci. Technol. 62, 273284.Google Scholar
Batchelor, G. K. 1953 The Theory of Homogeneous Turbulence. Cambridge University Press.
Becker, H., Monkhouse, P. B., Wolfrum, J., Cant, R. S., Bray, K. N. C., Maly, R., Pfister, W., Stahl, G. & Warnatz, J. 1990 Investigation of extinction in unsteady flames in turbulent combustion by 2D-LIF of OH radicals and flamelet analysis. In 23rd Symp. (Intl) on Combustion, pp. 817823. The Combustion Institute, Pittsburgh.
Blint, R. J. 1988 Flammability limits for exhaust gas diluted flames. In 22nd Symp. (Intl) on Combustion, pp. 15471554. The Combustion Institute, Pittsburgh.
Blint, R. J. 1991 Stretch in premixed laminar flames under IC engine conditions. Combust. Sci. Technol. 75, 115128.Google Scholar
Boudier, P., Henriot, S., Poinsot, T. & Baritaud, T. 1992 A model for turbulent flame ignition and propagation in spark ignition engines. In 24th Symp. (Intl) on Combustion, pp. 503510. The Combustion Institute, Pittsburgh.
Bray, K. N. C. & Cant, R. S. 1991 Some applications of Kolmogorov's turbulence research in the field of combustion. Proc. R. Soc. Lond. A, 434, 217240.Google Scholar
Candel, S. M. & Poinsot, T. J. 1990 Flame stretch and the balance equation for the flame area. Combust. Sci. Technol. 70, 115.Google Scholar
Cant, R. S., Rutland, C. J. & Trouvé, A. 1990 Statistics for laminar flamelet modeling. In Proc. 1990 Summer Program, pp. 271279. Center for Turbulence Research, Stanford University & NASA Ames.
Chelliah, H. K. & Williams, F. A. 1987 Asymptotic analysis of two-reactant flames with variable properties and Stefan–Maxwell transport. Combust. Sci. Technol. 51, 129144.Google Scholar
Clavin, P. & Williams, F. 1982 Effects of molecular diffusion and of thermal expansion on the structure and dynamics of premixed flames in turbulent flows of large scale and low intensity. J. Fluid Mech. 116, 251282.Google Scholar
Darabiha, N. & Candel, S. 1992 The influence of the temperature on extinction and ignition limits of strained hydrogen-air diffusion flames. Combust. Sci. Technol. 86, 6785.Google Scholar
Darabiha, N., Giovangigli, V., Candel, S. & Smooke, M. D. 1989 Vectorized computation of complex chemistry flames. In Proc. Intl Symp. on High Performance Computing, Montpellier, France (ed. J. Delhaye & E. Gelenbe). Elsevier.
Dixon-Lewis, G. & Missaghi 1988 Structure and extinction limits of counterflow diffusion flames of hydrogen nitrogen mixture in air. In 22nd Symp. (Intl) on Combustion, pp. 14611470. The Combustion Institute, Pittsburgh.
Dixon-Lewis, G. & Williams, D. 1979 The oxidation of hydrogen and carbon monoxide. Phil. Trans. R. Soc. Lond. A 292, 4599.Google Scholar
Drake, M. C. & Blint, R. J. 1988 Structure of laminar opposed-flow diffusion flames with CO/H2/N2 fuel. Combust. Sci. Technol. 61, 187224.Google Scholar
El Tahry, S. H. 1990 A turbulence combustion model for premixed charge engines. Combust. flame 79, 122140.Google Scholar
El Tahry, S. H., Rutland, S. H. & Ferziger, J. H. 1991 Structure and propagation speeds of turbulent premixed flames – a numerical study. Combust. Flame 83, 155173.Google Scholar
Garcia-Ybarra, P., Nicoli, C. & Calvin, P. 1984 Soret and dilution effects on premixed flames. Combust. Sci. Technol. 42, 87109.Google Scholar
Ghoniem, A. F. & Krishnan, A. 1988 Origin and manifestation of flow combustion interactions in a premixed shear layer. In 22nd Symp. (Intl) on Combustion, pp. 665657. The Combustion Institute, Pittsburgh.
Giovangigli, V. & Smooke, M. 1987a Calculation of extinction limits for premixed laminar flames in a stagnation point flow. J. Comput. Phys. 68, 327345.Google Scholar
Giovangigli, V. & Smooke, M. 1987b Extinction of strained premixed laminar flames with complex chemistry. Combust. Sci. Technol. 53, 2349.Google Scholar
Giovangigli, V. & Smooke, M. 1988 Adaptive continuation algorithms with applications to combustion problems. Appl. Numer. Math. 5, 305.Google Scholar
Girimaji, S. S. & Pope, S. B. 1992 Propagating surfaces in isotropic turbulence. J. Fluid Mech. 234, 247277.Google Scholar
Haworth, D. C. & Poinsot, T. J. 1992 Numerical simulations of Lewis number effects in turbulent premixed flames. J. Fluid Mech. 244, 405436.Google Scholar
Herring, J. R., Orszag, S. A., Kraichnan, R. H. & Fox, D. G. 1974 Decay of two-dimensional homogeneous turbulence. J. Fluid Mech. 66, 417444.Google Scholar
Hinze, J. O. 1975 Turbulence, 2nd edn. McGraw-Hill.
Hurle, I., Price, R., Sugden, T. & Thomas, A. 1968 Sound emission from open turbulent premixed flames. Proc. R. Soc. Lond. A 303, 409427.Google Scholar
Joulin, G. & Mitani, T. 1981 Linear stability analysis of two-reactant flames. Combust. Flame 40, 235246.Google Scholar
Kee, R., Miller, J., Evans, G. & Dixon-Lewis, G. 1988 A computational model of the structure and extinction of strained opposed flow, premixed methane air flames. In 22nd Symp. (Intl) on Combustion, pp. 14791494. The Combustion Institute.
Kee, R. J., Miller, J. A. & Jefferson, T. H. 1980 Chemkin: a general-purpose, problem-independent, transportable, fortran chemical-kinetics code package. Sandia Tech. Rep. SAND80–8003.
Kee, R. J., Warnatz, J. & Miller, J. A. 1983 A fortran computer code package for the evaluation of gas-phase viscosities, conductivities, and diffusion coefficients. Sandia Tech. Rep. SAND83–8209.
Kerstein, A. R., Ashurst, W. T. & Williams, F. A. 1988 Field equations for interface propagation in an unsteady homogeneous flowfield. Phys. Rev. A 37, 27282731.Google Scholar
Kwon, S., Tseng, L.-K. & Faeth, G. 1992 Laminar burning velocities and transition to unstable flames in H2/O2/N2 and C3H8/O2/N2 mixtures. Combust. Flame 90, 230246.Google Scholar
Lee, T.-W., Lee, J., Nye, D. & Santavicca, D. A. 1993 Local response and surface properties of premixed flames during interactions with kármán vortex streets. Combust. Flame 94, 146160.Google Scholar
Lee, T.-W., North, G. L. & Santavicca, D. A. 1992 Curvature and orientation statistics of turbulent premixed flame fronts. Combust. Sci. Technol. 84, 121132.Google Scholar
Lele, S. 1992 Compact finite difference schemes with spectral-like resolution. J. Comput. Phys. 103, 1642.Google Scholar
Lesieur, M. 1987 Turbulence in Fluids. Martinus Nijhoff.
Mantzaras, J., Felton, P. G. & Bracco, F. V. 1988 Three-dimensional visualization of premixed-charge engine flames. SAE. Tech. Rep. 881635.
Meneveau, C. & Poinsot, T. 1990 Stretching and quenching of flamelets in premixed turbulent combustion. Combust. Flame 86, 311332.Google Scholar
Miller, J. A., Mitchell, R. E., Smooke, M. D. & Lee, R. J. 1982 Toward a comprehensive chemical kinetic mechanism for the oxidation of acetylene: comparison of model predictions with results from flame and shock tube experiments. In 19th Symp. (Intl) on Combustion, pp. 181196. The Combustion Institute, Pittsburgh.
Montgomery, C. J., Kosaly, G. & Riley, J. 1993 Direct numerical simulation of turbulent reacting flow using a reduced hydrogen–oxygen mechanism. Combust. Flame 94, 247260.Google Scholar
Oran, E. S. & Boris, J. P. 1987 Numerical Simulation of Reactive Flow, Elsevier.
Poinsot, T. 1991 Flame ignition in a premixed turbulent flow. In Center for Turbulence Research Annual Research Briefs, pp. 122, Stanford University. Center for Turbulence Research & NASA Ames.
Poinsot, T., Echekki, T. & Mungal, M. G. 1992 A study of the laminar flame tip and implications for premixed turbulent combustion. Combust. Sci. Technol. 81, 4555.Google Scholar
Poinsot, T. J., Haworth, D. C. & Bruneaux, G. 1993 Direct simulation and modelling of flame-wall interaction for turbulent premixed combustion. Combust. Flame 94, 118132.Google Scholar
Poinsot, T. & Lele, S. 1992 Boundary conditions for direct simulations of compressible viscous flows. J. Comput. Phys. 101, 104129.Google Scholar
Poinsot, T., Trouvé, A., Veynante, D., Candel, S. & Esposito, E. 1987 Vortex driven acoustically coupled combustion instabilities. J. Fluid Mech. 177, 265292.Google Scholar
Poinsot, T., Veynante, D. & Candel, S. 1990 Diagrams of premixed turbulent combustion based on direct simulation. In 23rd Symp. (Intl) on Combustion, pp. 613619. The Combustion Institute, Pittsburgh.
Poinsot, T., Veynante, D. & Candel, S. 1991 Quenching processes and premixed turbulent combustion diagrams. J. Fluid Mech. 228, 561606.Google Scholar
Pope, S. B. 1988 Evolution of surfaces in turbulence. Intl J. Engng. Sci. 26, 445469.Google Scholar
Pope, S. B. 1991 Numerical issues in p.d.f. methods. In Fourth Intl Conf. on Numerical Combustion, St. Petersburg, FL, p. 165. SIAM.
Rutland, C. J., Ferziger, J. H. & El Tahry, S. H. 1990 Full numerical simulation and modeling of turbulent premixed flames. In 23rd Symp. (Intl) on Combustion, pp. 621627. The Combustion Institute, Pittsburgh.
Rutland, C. & Trouvé, A. 1990 Premixed flame simulations for nonunity lewis numbers. In Proc. 1990 Summer Program, pp. 299309, Stanford University. Center for Turbulence Research & NASA Ames.
Rutland, C. & Trouvé, A. 1993 Direct simulations of premixed turbulent flames with nonunity Lewis numbers. Combust. Flame 94, 4157.Google Scholar
Searby, G. & Quinard, J. 1990 Direct and indirect measurements of markstein numbers of premixed flames. Combust. Flame 82, 289311.Google Scholar
Smooke, M. 1982 Solution of burner stabilized premixed laminar flames by boundary value method. J. Comput. Phys. 48, 72105.Google Scholar
Smooke, M. D., Lin, P., Lam, J. & Long, M. B. 1990 Computational and experimental study of a laminar axisymmetric methane–air diffusion flame. In 23rd Symp. (Intl) on Combustion, pp. 575582. The Combustion Institute, Pittsburgh.
Trouvé, A. & Poinsot, T. 1994 The evolution equation for the flame surface density in turbulent premixed combustion. J. Fluid Mech. 278, 131.Google Scholar
Warnatz, J. 1981 Concentration-, pressure-, and temperature-dependence of the flame velocity in hydrogen–oxygen–nitrogen mixtures. Combust. Sci. Technol. 26, 203213.Google Scholar
Westbrook, C. & Dryer, F. 1984 Chemical kinetic modelling of hydrocarbon combustion. Prog. Energ. Combust. Sci. 10, 157.Google Scholar
Wu, M., Kwon, S., Driscoll, J. & Faeth, G. 1990 Turbulent premixed hydrogen/air flames at high reynolds numbers. Combust. Sci. Technol. 73, 327350.Google Scholar
Xu, Y. & Smooke, M. D. 1991 Primitive variable solution of a confined laminar diffusion flame using a detailed reaction mechanism. In Fourth Intl Conf. on Numerical Combustion, St Petersburg, FL, pp. 228229. SIAM.