Identification and analysis of coherent structures in the near field of a turbulent unconfined annular swirling jet using large eddy simulation

Large eddy simulations of incompressible turbulent flow in an unconfined annular swirling jet at Reynolds number 81500 are reported, based on the outer radius of the jet. The results are in excellent agreement with experimental data for mean flow, turbulent statistics, and power spectral densities of velocity fluctuations. Two dominant families of large-scale coherent structures are identified in the flow. Both are orthogonal to the mean three-dimensional streamlines, which suggests that they are formed as the result of a Kelvin-Helmholtz instability. Instantaneous vortex structures as well as different types of spectra and two-point correlations are presented to further elucidate the properties of the flow.

[1]  János M. Beér,et al.  Combustion in swirling flows: A review , 1974 .

[2]  P. Moin,et al.  Large-eddy simulation of turbulent confined coannular jets , 1996, Journal of Fluid Mechanics.

[3]  D. Lilly,et al.  A proposed modification of the Germano subgrid‐scale closure method , 1992 .

[4]  Alan V. Oppenheim,et al.  Discrete-Time Signal Pro-cessing , 1989 .

[5]  Jörg Uwe Schlüter.  Large Eddy Simulations of flow and mixing in jets and swirl flows : application to a gas turbine , 2000 .

[6]  Johannes Janicka,et al.  Assessment of Unsteady RANS in Predicting Swirl Flow Instability Based on LES and Experiments , 2004 .

[7]  D Froud,et al.  The Interaction of the Precessing Vortex Core and Reverse Flow Zone in the Exhaust of a Swirl Burner , 1994 .

[8]  Jochen Fröhlich,et al.  Highly resolved large-eddy simulation of separated flow in a channel with streamwise periodic constrictions , 2005, Journal of Fluid Mechanics.

[9]  C. Külsheimer,et al.  Combustion dynamics of turbulent swirling flames , 2002 .

[10]  A. Mestre,et al.  Combustion in swirling flow , 1973 .

[11]  X. Bai,et al.  Large eddy simulation and experimental studies of a confined turbulent swirling flow , 2004 .

[12]  J. Fröhlich,et al.  On the Sensitivity of a Free Annular Swirling Jet to the Level of Swirl and a Pilot Jet , 2005 .

[13]  T. Maxworthy,et al.  Three-dimensional vortex breakdown in swirling jets and wakes: direct numerical simulation , 2003, Journal of Fluid Mechanics.

[14]  Parviz Moin,et al.  An improvement of fractional step methods for the incompressible Navier-Stokes equations , 1991 .

[15]  C. Rhie,et al.  Numerical Study of the Turbulent Flow Past an Airfoil with Trailing Edge Separation , 1983 .

[16]  Y. Dubief,et al.  On coherent-vortex identification in turbulence , 2000 .

[17]  Andrew Pollard,et al.  Large eddy simulation of the effects of mild swirl on the near field of a round free jet , 2002 .

[18]  N. Syred,et al.  The Effect of the Precessing Vortex Core on Combustion in a Swirl Burner , 1997 .

[19]  François Gallaire,et al.  Mode selection in swirling jet experiments: a linear stability analysis , 2003, Journal of Fluid Mechanics.

[20]  R. Blevins,et al.  Flow-Induced Vibration , 1977 .

[21]  B. E. Launder,et al.  Closure Strategies for Turbulent and Transitional Flows , 2002 .

[22]  W. Rodi,et al.  Closure Strategies for Turbulent and Transitional Flows: Introduction to Large Eddy Simulation of Turbulent Flows , 2002 .

[23]  C. Pierce,et al.  LARGE EDDY SIMULATION OF A CONFINED COAXIAL JET WITH SWIRL AND HEAT RELEASE , 1998 .

[24]  S. Vanka,et al.  Application of Laser Velocimetry for Characterization of Confined Swirling Flow , 1988 .

[25]  T. Sarpkaya.  On stationary and travelling vortex breakdowns , 1971, Journal of Fluid Mechanics.

[26]  Christian Oliver Paschereit,et al.  Coherent structures in swirling flows and their role in acoustic combustion control , 1999 .

[27]  John K. Harvey,et al.  Some observations of the vortex breakdown phenomenon , 1962, Journal of Fluid Mechanics.

[28]  Jinhee Jeong,et al.  On the identification of a vortex , 1995, Journal of Fluid Mechanics.

[29]  T. O’Doherty,et al.  Vortex breakdown: a review , 2001 .

[30]  V. Yang,et al.  Unsteady flow evolution in swirl injectors with radial entry. II. External excitations , 2005 .

[31]  Vigor Yang,et al.  Large-Eddy Simulation of Combustion Dynamics of Lean-Premixed Swirl-Stabilized Combustor , 2003 .

[32]  P. Moin,et al.  A dynamic subgrid‐scale eddy viscosity model , 1990 .

[33]  S. Leibovich.  Vortex stability and breakdown - Survey and extension , 1984 .

[34]  C. M. Coats,et al.  Coherent structures in combustion , 1996 .

[35]  S. Sarkar,et al.  Large eddy simulation of a plane jet , 1999 .

[36]  Martin Sommerfeld,et al.  Detailed measurements in a swirling particulate two-phase flow by a phase-Doppler anemometer , 1991 .

[37]  Rhj Sellin,et al.  Engineering Turbulence - Modelling and experiments 3 , 1996 .

[38]  S. Menon,et al.  LES of spray combustion in swirling flows , 2002 .

[39]  Amsini Sadiki,et al.  Large eddy simulation of combustion processes under gas turbine conditions , 2004 .

[40]  T. Sarpkaya.  Turbulent vortex breakdown , 1995 .

[41]  H. Mongia,et al.  Large-Eddy Simulation of a Gas Turbine Combustor Flow , 1999 .

[42]  R. Roback,et al.  Mass and Momentum Turbulent Transport. Experiments with Confined Swirling Coaxial Jets , 1984 .

[43]  P. Moin,et al.  Large-eddy simulation of swirling particle-laden flows in a coaxial-jet combustor , 2003 .

[44]  J. Chomaz,et al.  Experimental study of vortex breakdown in swirling jets , 1998, Journal of Fluid Mechanics.

[45]  H. L. Stone.  ITERATIVE SOLUTION OF IMPLICIT APPROXIMATIONS OF MULTIDIMENSIONAL PARTIAL DIFFERENTIAL EQUATIONS , 1968 .

[46]  Christof Hinterberger,et al.  Dreidimensionale und tiefengemittelte Large-Eddy-Simulation von Flachwasserströmungen , 2004 .

[47]  Dennis K. McLaughlin,et al.  Experiments on the instabilities of a swirling jet , 1994 .

[48]  V. Yang,et al.  Large-eddy simulations of turbulent swirling flows injected into a dump chamber , 2005, Journal of Fluid Mechanics.

[49]  V. Yang,et al.  Unsteady flow evolution in swirl injector with radial entry. I. Stationary conditions , 2005 .

[50]  G. Balarac,et al.  Transition in high velocity ratio coaxial jets analysed from direct numerical simulations , 2003 .

[51]  Timothy O'Doherty,et al.  Phase averaging of the precessing vortex core in a swirl burner under piloted and premixed combustion conditions , 1995 .