On the formation of the counter-rotating vortex pair in transverse jets

Among the important physical phenomena associated with the jet in crossflow is the formation and evolution of vortical structures in the flow field, in particular the counter-rotating vortex pair (CVP) associated with the jet cross-section. The present computational study focuses on the mechanisms for the dynamical generation and evolution of these vortical structures. Transient numerical simulations of the flow field are performed using three-dimensional vortex elements. Vortex ring rollup, interactions, tilting, and folding are observed in the near field, consistent with the ideas described in the experimental work of Kelso, Lim & Perry (1996), for example. The time-averaged effect of these jet shear layer vortices, even over a single period of their evolution, is seen to result in initiation of the CVP. Further insight into the topology of the flow field, the formation of wake vortices, the entrainment of crossflow, and the effect of upstream boundary layer thickness is also provided in this study.

[1]  T. Sarpkaya.  Computational Methods With Vortices—The 1988 Freeman Scholar Lecture , 1989 .

[2]  W. Dahm,et al.  Vortex structure and dynamics in the near field of a coaxial jet , 1992, Journal of Fluid Mechanics.

[3]  D. M. Kuzo,et al.  An experimental study of the turbulent transverse jet , 1996 .

[4]  Alexander J. Smits,et al.  Horseshoe vortex systems resulting from the interaction between a laminar boundary layer and a transverse jet , 1995 .

[5]  Adnan Eroglu,et al.  Effects of periodic disturbances on structure and flame length of a jet in a crossflow , 1991 .

[6]  Hamid Johari,et al.  Duty-Cycle Effects on Penetration of Fully Modulated, Turbulent Jets in Crossflow , 1998 .

[7]  M. Mungal,et al.  Mixing, structure and scaling of the jet in crossflow , 1998, Journal of Fluid Mechanics.

[8]  Ann Karagozian,et al.  Transverse gas jet injection behind a rearward-facing step , 1996 .

[9]  Ann Karagozian.  An analytical model for the vorticity associated with a transverse jet , 1986 .

[10]  Eckart Meiburg,et al.  Numerical investigation of three-dimensionally evolving jets under helical perturbations , 1992, Journal of Fluid Mechanics.

[11]  R. C. Rogers,et al.  Numerical predictions of a rearward-facing-step flow in a supersonic combustor , 1989 .

[12]  Yasuhiro Kamotani,et al.  Experiments on a Turbulent Jet in a Cross Flow , 1972 .

[13]  Eckart Meiburg,et al.  Three-dimensional shear layers via vortex dynamics , 1988, Journal of Fluid Mechanics.

[14]  A. Roshko,et al.  Vortical structure in the wake of a transverse jet , 1994, Journal of Fluid Mechanics.

[15]  A. Karagozian,et al.  The flame structure and vorticity generated by a chemically reacting transverse jet , 1986 .

[16]  Robert Krasny,et al.  A numerical study of vortex ring formation at the edge of a circular tube , 1994, Journal of Fluid Mechanics.

[17]  W. Ashurst,et al.  LARGE EDDY SIMULATION via VORTEX DYNAMICS , 1983 .

[18]  Z. Moussa,et al.  The near field in the mixing of a round jet with a cross-stream , 1977, Journal of Fluid Mechanics.

[19]  J. Hermanson,et al.  Penetration and Mixing of Fully Modulated Turbulent Jets in Crossflow , 1999 .

[20]  Eckart Meiburg,et al.  Numerical investigation of three-dimensionally evolving jets subject to axisymmetric and azimuthal perturbations , 1991, Journal of Fluid Mechanics.

[21]  T. Brzustowski,et al.  The hydrocarbon turbulent diffusion flame in subsonic cross-flow , 1977 .

[22]  J. Broadwell,et al.  Structure and mixing of a transverse jet in incompressible flow , 1984, Journal of Fluid Mechanics.

[23]  F. Steward.  Prediction of the Height of Turbulent Diffusion Buoyant Flames , 1970 .

[24]  R. P. Weston,et al.  Vorticity Associated with a Jet in a Cross Flow , 1974 .

[25]  A. Leonard.  Computing Three-Dimensional Incompressible Flows with Vortex Elements , 1985 .

[26]  Lester L. Yuan,et al.  Large-eddy simulations of a round jet in crossflow , 1999, Journal of Fluid Mechanics.

[27]  Ahmed F. Ghoniem,et al.  Three-Dimensional Vortex Simulation of Time Dependent Incompressible Internal Viscous Flows , 1997 .

[28]  A. Roshko,et al.  Structure in the Near Field of the Transverse Jet , 1989 .

[29]  H. C. Hottel.  Burning in laminar and turbulent fuel jets , 1953 .

[30]  Petros Koumoutsakos,et al.  Vortex Methods: Theory and Practice , 2000 .

[31]  Lester L. Yuan,et al.  Trajectory and entrainment of a round jet in crossflow , 1998 .

[32]  Roland H. Krauss,et al.  Experimental Supersonic Hydrogen Combustion Employing Staged Injection Behind a Rearward-Facing Step , 1993 .

[33]  W. Rodi,et al.  Experimental investigation of jets in a crossflow , 1982, Journal of Fluid Mechanics.

[34]  J. Hunt,et al.  The dynamics of the near field of strong jets in crossflows , 1989, Journal of Fluid Mechanics.

[35]  A. Leonard,et al.  Bifurcating jets at high Reynolds numbers , 1988 .

[36]  Anjaneyulu Krothapalli,et al.  Separated flow upstream of a jet in a crossflow , 1990 .

[37]  A. Perry,et al.  An experimental study of round jets in cross-flow , 1996, Journal of Fluid Mechanics.