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A PIV investigation of the characteristics of micro-scale synthetic jets

Published online by Cambridge University Press:  03 February 2016

F. Guo
Affiliation:
School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester, UK
S. Zhong
Affiliation:
School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester, UK

Abstract

Although macro-scale synthetic jets are well studied, our knowledge of the behaviour of micro-scale synthetic jets is still extremely limited due to the difficulty in performing detailed measurements with a desirable spatial solution. In the work presented in this paper, a PIV study of the characteristics of synthetic jets issued into quiescent air from orifices of 5mm and 0·5mm diameter respectively is undertaken. It is found that the vortex rollup is much weaker for the 0·5mm jets due to their low Stokes number which results in a near parabolic exit velocity profile. To ensure an appreciable vortex rollup that is desirable for effective flow control, the actuator has to be operated at much higher frequencies to ensure that the Stokes number is greater than a certain threshold value. Furthermore the study shows that the characteristics of synthetic jets of different scales are identical when the dimensionless stroke length (L), Stokes number (S) and Reynolds number (ReL) are the same. On the basis of these scaling parameters, the finding acquired from the studies on macro-scale actuators can be applicable to micro-scale actuators, which are more difficult to measure. Finally, it is also found that although the linear relationships between (L and ReL) and actuator operating conditions observed for macro-scale synthetic jets are no longer valid for micro-scale synthetic jets, the linear relationships between the dimensionless jet performance parameters and (L and ReL) still exist for micro-scale synthetic jets.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 2007 

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References

1. Glezer, A. and Amitay, M. Synthetic jets, Ann Rev Fluid Mech, 2002, 34, pp 503529.Google Scholar
2. Smith, B.L. and Glezer, A. The formation and evolution of synthetic jets, Physics of Fluids, 1998, 10, (9), pp 22812297.Google Scholar
3. Cater, J.E. and Soria, J. The evolution of round zero-net-mass-flux jets. J Fluid Mechanics, 2002, 472, pp 167200.Google Scholar
4. Crook, A. and Wood, N.J. Measurements and visualisation of synthetic jets, January 2001, AIAA Paper 2001-0145, 39th Aerospace Meeting and Exhibit, Reno, Nevada, USA.Google Scholar
5. Zhong, S., Mullet, F. and Wood, N.J. Interaction of circular synthetic jets with a laminar boundary layer, Aeronaut J, 2005, 109, (1100), pp 461470.Google Scholar
6. Tang, H. and Zhong, S. Incompressible flow model for synthetic jets actuators, AIAA J, 2006, 44, (4), pp 908912.Google Scholar
7. Crittenden, T.M. and Glezer, A. A high-speed compressible synthetic jet, Physics of Fluids, 2006, 18, 017107.Google Scholar
8. Jabbal, M., Wu, J. and Zhong, S. The performance of round synthetic jets in quiescent flow, Aeronaut J, 2006, 110, (1108), pp 385393.Google Scholar
9. Crook, A. and Wood, N.J. A Parametric investigation of a synthetic jet in quiescent conditions, 2000, Ninth International Symposium on Flow Visualization, Edinburgh.Google Scholar
10. Tang, H. and Zhong, S. The effect of actuator geometry on the performance of synthetic jets, 2005, CEAS/KATnet Conference on Key Aerodynamic Technologies, Bremen, Germany.Google Scholar
11. Lin, J.C. Control of turbulent boundary-layer separation using micro-vortex generators, 1999, AIAA Paper 99-3404.Google Scholar
12. Tang, H. Performance Modelling of Synthetic Jet Actuators for Flow Separation Control, 2006, PhD thesis, School of Mechanical, Aerospace and Civil Engineering, Manchester University.Google Scholar
13. Jabbal, M. and Zhong, S. The near-wall effect of synthetic jets in a laminar boundary layer, 2006, Third AIAA Flow Control Conference, AIAA-2006-3180, San Francisco, USA.Google Scholar
14. Private communication with Wood, N.J., 2005.Google Scholar
15. Tang, H. and Zhong, S. Modelling of the characteristics of synthetic jet actuators using the lumped element model, 2006, Third AIAA Flow Control Conference, AIAA-2006-3696, San Francisco, USA.Google Scholar