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The behaviour of circular synthetic jets in a laminar boundary layer

Published online by Cambridge University Press:  03 February 2016

S. Zhong ,
F. Millet  and
N. J. Wood
S. Zhong
Affiliation:
School of Mechanical, Aerospace and Civil Engineering, Manchester University, UK
F. Millet
Affiliation:
School of Mechanical, Aerospace and Civil Engineering, Manchester University, UK
N. J. Wood
Affiliation:
School of Mechanical, Aerospace and Civil Engineering, Manchester University, UK
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Abstract

Dye flow visualisation of circular synthetic jets was carried out in laminar boundary layers developing over a flat plate at a range of actuator operating conditions and freestream velocities of 0·05 and 0·1ms–1. The purpose of this work was to study the interaction of synthetic jets with the boundary layer and the nature of vortical structures produced as a result of this interaction. The effects of Reynolds number (Re), velocity ratio (VR) and Strouhal number (St) on the behaviour of synthetic jets were studied. At low Re and VR, the vortical structures produced by synthetic jets appear as highly stretched hairpin vortices attached to the wall. At intermediate Re and VR, these structures roll up into vortex rings which experience a considerable amount of tilting and stretching as they enter the boundary layer. These vortex rings will eventually propagate outside the boundary layer hence the influence of the synthetic jets on the near wall flow will be confined in the near field of the jet exit. At high Re and VR, the vortex rings appear to experience a certain amount of tilting but no obvious stretching. They penetrate the edge of the boundary layer quickly, producing very limited impact on the near wall flow. Hence it is believed that the hairpin vortices produced at low Re and VR are likely to be the desirable structures for effective flow separation control. In this paper, a vortex model was also described to explain the mechanism of vortex tilting.

Type
Research Article
Information
The Aeronautical Journal , Volume 109 , Issue 1100 , October 2005 , pp. 461 - 470
Copyright
Copyright © Royal Aeronautical Society 2005 

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References

1. James, R.D., Jacobs, J.W. and Glezer, A.. A round turbulent jet produced by an oscillating diaphragm, Phys of Fluids, 1996, 8, (9), pp 2481–2495.Google Scholar
2. Smith, B.L. and Glezer, A.. The formation and evolution of synthetic jets, Phys of Fluids, 1998, 10, pp 2281–2297.Google Scholar
3. Seifert, A., Bachar, T., Koss, D., Shepshelovich, M. and Wygnanski, I.. Oscillatory blowing: a tool to delay boundary-layer separation, AIAA J, 1993, 31, (11).Google Scholar
4. McMichael, J.M.. Progress and prospects for active flow control using microfabricated electro-mechanical systems (MEMS), AIAA paper 96-0306, 1996.Google Scholar
5. Gad-el-Hak, M.. Modern developments in flow control, Applied Mech Rev, 1996, 49, (7), pp 365–379.Google Scholar
6. Amitay, M., Smith, B.L. and Glezer, A.. Aerodynamic flow control using synthetic jet technology, AIAA Paper 98-0208, 1998.Google Scholar
7. Amitay, M., Kinbens, V., Parekh, D. and Glezer, A.. The dynamics of flow reattachment over a thick airfoil controlled by synthetic jet actuators, AIAA Paper 99-1001, 1999.Google Scholar
8. Crook, A. and Wood, N.J.. A parametric study of a synthetic jet in quiescent conditions, 9th International Symposium on Flow Visualisation, Paper 67, Edinburgh, UK, 2000.Google Scholar
9. Crook, A., Sadri, A.M. and Wood, N.J.. The development and implementation of synthetic jets for the control of separated flow, AIAA paper 99-3176, 17th Applied Aerodynamics Conference, Norfolk, July 1999.Google Scholar
10. Crook, A., Crowther, W.J. and Wood, N.J.. A parametric study of a synthetic jet in a cross flow, 22nd International Congress of Aeronautical Sciences, Harrogate, UK, 2000.Google Scholar
11. Crook, A., Crowther, W.J. and Wood, N.J.. Measurements and visualisations of synthetic jets, AIAA paper 2001-0145, 39th Aerospace Sciences Meeting and Exhibit, Reno, Nevada, January 2001.Google Scholar
12. Glezer, A. and Amitay, M.. Synthetic jets, Annual Review Fluid Mech, 2002, 34, pp 503–529.Google Scholar
13. Tang, H. and Zhong, S.. Development of prediction models for synthetic jets in quiescent conditions using FLUENT, AIAA paper 2005-0104, The 43rd Aerospace Sciences Meeting and Exhibit, Reno, Nevada, USA, January 2005.Google Scholar
14. Tang, H. and Zhong, S.. 2D simulation of circular synthetic jets in quiescent conditions, Aeronaut J, 2005, 109, (1092), pp 89–97.Google Scholar
15. Head, M.R. and Bandyopadyay, P.. New aspects of turbulent boundary-layer structure, J Fluid Mech, 1981, 107, pp 297–338.Google Scholar
16. Chang, Y.K. and Vakili, A.D.. Dynamics of vortex rings in crossflow, Physics of Fluids, 1995, 7, pp 1583–1597.Google Scholar
17. Ting, L. and Tung, C.. Motion and decay of a vortex in a non-uniform stream, Physics of Fluids, 1965, 8, p 1039.Google Scholar