Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-21T12:20:24.791Z Has data issue: false hasContentIssue false
  • English
  • Français

The evolution of a jet with vortex-generating tabs: real-time visualization and quantitative measurements

Published online by Cambridge University Press:  26 April 2006

M. F. Reeder  and
M. Samimy
M. F. Reeder
Affiliation:
The Ohio State University, Department of Mechanical Engineering, Columbus, OH 43210–1107, USA
M. Samimy
Affiliation:
The Ohio State University, Department of Mechanical Engineering, Columbus, OH 43210–1107, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental study involving flow visualization and two-component LDV measurements has been undertaken to elucidate the deformation of an axisymmetric jet (ReD ≈ 1950 and 4160) caused by tabs placed at the nozzle exit. Previous studies have shown the profound distortion of high-speed jets with tabs and have demonstrated that a pair of counter-rotating streamwise vortices generated by each tab are responsible for the deformation of the jet core. This work illustrates the distortion as well as some of the more subtle features of the tab effect. Extensive visualizations taken simultaneously from two perspectives reveal the real-time evolution of complex three-dimensional flow structures. Velocity data show the expected overall distortion, and the existence and strength of the streamwise vortices responsible for this deformation. Furthermore, a second set of weaker streamwise vortices was detected near each tab, the size and location of which was consistent with a horseshoe vortex system. The data showed a widespread increase in both Reynolds normal and shear stresses and generally indicated the accelerated development of the mixing layer when tabs were inserted. A brief analysis employing vortex dynamics - an alternative to previous work which utilized pressure gradient arguments-is used to explain the tab effect, resulting in similar conclusions.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 311 , 25 March 1996 , pp. 73 - 118
Copyright
© 1996 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

Acarlar, M. S. & Smith, C. R. 1987 A study of hairpin vortices in a laminar boundary layer. Part 1. Hairpin vortices generated by a hemisphere protuberance. J. Fluid Mech. 175, 1–41.Google Scholar
Ahuja, K. K. & Brown, W. H. 1989 Shear flow control by mechanical tabs. AIAA Paper 89-0994.Google Scholar
Andreopouolos, J. & Rodi, W. 1984 Experimental investigation of jets in crossflow. J. Fluid Mech. 138, 93–127.Google Scholar
Ashurst, W. T. & Meiburg, E. 1988 Three-dimensional shear layers via vortex dynamics. J. Fluid Mech. 189, 87–116.Google Scholar
Bell, J. H. & Mehta, R. D. 1992 Measurements of the streamwise vortical structures in a plane mixing layer. J. Fluid Mech. 239, 213–248.Google Scholar
Bell, J. H. & Mehta, R. D. 1993 Effects of spanwise perturbations on plane mixing-layer structure. J. Fluid Mech. 257, 33–63.Google Scholar
Bernal, L. P. & Roshko, A. 1986 Streamwise vortex structures in plane mixing layers. J. Fluid Mech. 170, 499–525.Google Scholar
Bradbury, L. J. S. & Khadem, A. H. 1975 The distortion of a jet by tabs. J. Fluid Mech. 70, 801–813.Google Scholar
Bradshaw, P. 1987 Turbulent secondary flows. Ann. Rev. Fluid Mech. 19, 53–74.Google Scholar
Breidenthal, R. 1981 Structure in turbulent shear layers and wakes using a chemical reaction. J. Fluid Mech. 109, 1–24.Google Scholar
Browand, F. K. & Troutt, T. R. 1980 A note on spanwise structure in the two-dimensional mixing layer. J. Fluid Mech. 97, 771–781.Google Scholar
Brown, G. L. & Roshko, A. 1974 On density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775–816.Google Scholar
Cantwell, B. J. 1981 Organized motions in turbulent flow. Ann. Rev. Fluid Mech. 13, 457–515.Google Scholar
Corcos, G. M. & Lin, S. J. 1984 The mixing layer: deterministic models of turbulent flow. Part 2: the origin of three-dimensional motion. J. Fluid Mech. 139, 67–95.Google Scholar
Crow, S. C. & Champagne, F. H. 1971 Orderly structure in jet turbulence. J. Fluid Mech. 48, 547–591.Google Scholar
Dimotakis, P. E., Miake-Lye, R. C. & Papantoniou, D. A. 1983 Structure and dynamics of round turbulent jets. Phys. Fluids 26, 3185–3192.Google Scholar
Ho, C. M. & Huerre, P. 1984 Perturbed free shear layers. Ann. Rev. Fluid Mech. 16, 365–424.Google Scholar
Hussain, F. & Husain, H. S. 1989 Elliptic jets. Part 1. Characteristics of unexcited and excited jets. J. Fluid Mech. 206, 257–320.Google Scholar
Jimenez, J. 1983 A spanwise structure in the plane shear layer. J. Fluid Mech. 132, 319–336.Google Scholar
Konrad, J. H. 1976 An experimental study of mixing in two-dimensional turbulent shear flows with applications to diffusion limited chemical reactions. Project SQUID Tech. Rep. CIT-8-PU.Google Scholar
Lasheras, J. C., Cho, J. S. & Maxworthy, T. 1986 On the origin and evolution of streamwise vortical structure in a plane, free shear layer. J. Fluid Mech. 172, 231–258.Google Scholar
Lasheras, J. C. & Choi, H. 1988 Three-dimensional instability of a plane free shear layer: an experimental study of the formation and evolution of streamwise vortices. J. Fluid Mech. 189, 53–86.Google Scholar
Liepmann, D. & Gharib, M. 1992 The role of streamwise vorticity in near-field entrainment of round jets. J. Fluid Mech. 245, 643–668.Google Scholar
Longmire, E. K., Eaton, J. K. & Elkins, C. J. 1992 Control of jet structure by crown-shaped nozzles. AIAA J. 30, 505–512.Google Scholar
Martin, J. E. & Meiburg, E. 1991 Numerical investigation of three-dimensionally evolving jets subject to axisymmetric and azimuthal perturbations. J. Fluid Mech. 230, 271–318.Google Scholar
Perkins, H. J. 1970 The formation of streamwise vorticity in turbulent flow. J. Fluid Mech. 44, 721–740.Google Scholar
Pierrehumbert, R. T. & Widnall, S. E. 1982 The two-and three-dimensional instabilities of a spatially periodic shear layer. J. Fluid Mech. 114, 59–82.Google Scholar
Prandtl, L. 1952 Essentials of Fluid Dynamics, pp. 145–149. Hafner Publishing Co..
Reeder, M. F. & Zaman, K. B. M. Q. 1994 The impact of ‘tab’ location relative to the nozzle exit on jet distortion. AIAA Paper 94-3385.Google Scholar
Reynolds, W. C. & Carr, L. W. 1985 Review of unsteady, driven separated flows. AIAA Paper 85-0527.Google Scholar
Samimy, M., Reeder, M. F. & Elliott, G. S. 1992 Compressibility effects on large structures in free shear flows. AIAA J. 4, 1251–1258.Google Scholar
Samimy, M., Zaman, K. B. M. Q. & Reeder, M. F. 1993 Effect of tabs on the flow and noise field of an axisymmetric jet. AIAA J. 31, 609–619.Google Scholar
Tanna, H. K. 1977 An experimental study of jet noise. Part 2: shock associated noise. J. Sound Vib. 50, 429–444.Google Scholar
Tillman, T. G., Paterson, R. W. & Presz, W. M. 1992 Supersonic mixer ejector. J Propulsion and Power 8, 513–519.Google Scholar
Winant, C. D. & Browand, F. K. 1974 Vortex pairing: the mechanism of structure growth at moderate Reynolds number. J. Fluid Mech. 63, 237–255.Google Scholar
Wishart, D. P., Krothapalli, A. & Mungal, M. G. 1993 Supersonic jet control via point disturbances inside the nozzle. AIAA J. 31, 1340–1341.Google Scholar
Yoda, M., Hesselink, L. & Mungal, M. G. 1992 The evolution and nature of large-scale structures in the turbulent jet.. Phys. Fluids A 4, 803–811.Google Scholar
Yule, A. J. 1978 Large scale structure in the mixing layer of a round jet. J. Fluid Mech. 89, 413–432.Google Scholar
Zaman, K. B. M. Q. 1993 Streamwise vorticity generation and mixing enhancement in free jets by ‘delta tabs’. AIAA Paper 93-3253.Google Scholar
Zaman, K. B. M. Q., Reeder, M. F. & Samimy, M. 1994 Control of an axisymmetric jet using vortex generators. Phys. Fluids 6, 778–793.Google Scholar