Cinematic particle image velocimetry of high-Reynolds-number turbulent free shear layer

The objective of this research was to study the time-evolving velocity field in a two-stream, turbulent, planar free shear layer using a cinematic partide image velocimetry technique. The water shear layer had a velocity ratio of 0.23 and a Reynolds number of 2.62 X 10 4 based on velocity thickness and velocity difference. The cinematic particle image velocimetry system employed an argon-ion laser, a scanning mirror, and a 35-mm movie camera. Experimental data obtained by this technique yielded a combined spatial and temporal evolution of the two-dimensional velocity and spanwise vorticity fields. The detailed velocity field structure of the shear layer was significantly different from previous lower Reynolds number flow visualizations in that the classical well-defined eddies and braids were replaced with complex three-dimensional agglomerated vortices of both signs. The velocity field evolution was also notably different from that of the passive scalar field, where the former exhibited stronger temporal variations and reduced spatial coherency. Temporal and spatial correlations yielded transverse distributions of convection velocities based on both streamwise velocity perturbations and vorticity.

[1]  Manoochehr Koochesfahani,et al.  Particle streak velocity field measurements in a two­ dimensional mixing layer , 1981 .

[2]  J. Wallace,et al.  The Statistical Properties of the Vorticity Field of a Two-Stream Turbulent Mixing Layer , 1989 .

[3]  B. G. Jones,et al.  Statistical investigation of pressure and velocity fields in the turbulent two-stream mixing layer , 1971 .

[4]  D. Lang,et al.  Two-Point LDV Measurements in a Plane Mixing Layer , 1979 .

[5]  Donald Rockwell,et al.  Cinematographic system for high-image-density particle image velocimetry , 1994 .

[6]  A Two-Phase Cinematic PIV Method for Bubbly Flows , 1997 .

[7]  P. Dimotakis,et al.  The mixing layer at high Reynolds number: large-structure dynamics and entrainment , 1976, Journal of Fluid Mechanics.

[8]  Clive A. Greated,et al.  An analysis of the scanning beam PIV illumination system , 1991 .

[9]  H. P. Planchon,et al.  Turbulent correlation measurements in a two-stream mixing layer. , 1973 .

[10]  R. Adrian,et al.  Effect of resolution on the speed and accuracy of particle image velocimetry interrogation , 1992 .

[11]  H. E. Fiedler,et al.  Limitation and improvement of PIV , 1993 .

[12]  J. Lasheras,et al.  Three-dimensional instability of a plane free shear layer: an experimental study of the formation and evolution of streamwise vortices , 1988, Journal of Fluid Mechanics.

[13]  C. Willert,et al.  Digital particle image velocimetry , 1991 .

[14]  J. Wills,et al.  On convection velocities in turbulent shear flows , 1964, Journal of Fluid Mechanics.

[15]  Donald Rockwell,et al.  High image-density particle image velocimetry using laser scanning techniques , 1993 .

[16]  J. J. Wang,et al.  Limitation and improvement of PIV: Part I: Limitation of conventional techniques due to deformation of particle image patterns , 1993 .

[17]  Richard D. Keane,et al.  Theory of cross-correlation analysis of PIV images , 1992 .

[18]  Jürgen Köhler,et al.  Cycle Resolved Flow Field Measurements Using a PIV Movie Technique in a SI Engine , 1992 .

[19]  D. D. Trump,et al.  Two-color particle-imaging velocimetry using a single argon-ion laser , 1994 .

[20]  Michael Fisher,et al.  The characteristics of the turbulence in the mixing region of a round jet , 1963, Journal of Fluid Mechanics.

[21]  Richard D. Keane,et al.  Optimization of particle image velocimeters. I, Double pulsed systems , 1990 .

[22]  R. G. Batt,et al.  Turbulent mixing of passive and chemically reacting species in a low-speed shear layer , 1977, Journal of Fluid Mechanics.

[23]  H. Fiedler,et al.  Transport of Heat Across a Plane Turbulent Mixing Layer , 1975 .

[24]  Robert D. Moser,et al.  Direct Simulation of a Self-Similar Turbulent Mixing Layer , 1994 .

[25]  A. T. Tung.  Properties of conditional eddies in free shear flows , 1982 .

[26]  R. Adrian.  Particle-Imaging Techniques for Experimental Fluid Mechanics , 1991 .

[27]  A Vogel,et al.  Time-resolved particle image velocimetry used in the investigation of cavitation bubble dynamics. , 1988, Applied optics.

[28]  R. J. Moffat,et al.  Contributions to the Theory of Single-Sample Uncertainty Analysis , 1982 .

[29]  P. Dimotakis.  Turbulent Free Shear Layer Mixing and Combustion , 1991 .

[30]  A. Roshko,et al.  On density effects and large structure in turbulent mixing layers , 1974, Journal of Fluid Mechanics.

[31]  D. Papamoschou,et al.  Evolution of large eddies in compressible shear layers , 1997 .

[32]  I. Wygnanski,et al.  The two-dimensional mixing region , 1970, Journal of Fluid Mechanics.

[33]  Javier Jiménez,et al.  Computer analysis of a high-speed film of the plane turbulent mixing layer , 1982, Journal of Fluid Mechanics.

[34]  Carl D. Meinhart,et al.  A parallel digital processor system for particle image velocimetry , 1993 .