Hostname: page-component-8448b6f56d-jr42d Total loading time: 0 Render date: 2024-04-16T20:46:08.675Z Has data issue: false hasContentIssue false

Reattachment of a Two-Dimensional, Incompressible Jet to an Adjacent Flat Plate*

Published online by Cambridge University Press:  07 June 2016

Get access

Summary

As part of a general investigation into Coanda effect, a study has been made of the reattachment of a two-dimensional, incompressible, turbulent jet to an adjacent, inclined, flat plate. The jet separates from the boundaries at the slot lips and reattaches to the plate downstream, a phenomenon which is associated with the lowering of the pressure between the jet and the plate accompanying the entrainment of fluid there. It is found that the flow becomes independent of both the length of the plate and the Reynolds number when these parameters are sufficiently large: the flow, scaled with respect to the width of the slot, is then uniquely determined by the plate inclination. Two approximate theories are developed for the mean pressure within the separation bubble, the position of reattachment and the increase in volume flow from the slot: the agreement with experiment is fairly satisfactory. These theories are a development of Dodds's analysis for the reattachment of a jet to a plate offset from, and parallel to, the axis of the slot and, for the purpose of comparison, a limited study is also made of this flow.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1960

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.)

Footnotes

*

This report is abstracted from the thesis “Déviation d'un Jet Turbulent Incompressible par un Volet Incliné–Effet Coanda” presented by the first author to the Université Laval for the degree of M.Sc. The work was supported by the Defence Research Board of Canada under grant number 9550-05.

References

1. Young, D. W. and Zonars, D. Wind Tunnel Tests of the Coanda Wing and Nozzle. U.S.A.F. Technical Report 6199, September 1950.Google Scholar
2. Sproule, R. S., Adderley, J. W. and Robinson, S. T. The Coanda Effect. C.I.O.S., S.H.A.E.F., Item No. 5, 1944.Google Scholar
3. Metral, A. Sur un Phénomène de Déviation des Veines Fluides et ses Applications. Effet Coanda. Cabinet Technique du Ministére de 1'Air, November 1938.Google Scholar
4. Metral, A. and Zerner, F. L'Effet Coanda. Publications Scientifiques et Techniques du Ministère de l'Air, No. 218, 1948; Ministry of Supply TIB/T4027, 1953.Google Scholar
5. Voedisch, A. Analytical Investigation of the Coanda Effect. Air Materiel Command, U.S.A.F. Wright Field, Technical Report F-TR-2155-ND, 1948.Google Scholar
6. Von kármán, T. Theoretical Remarks on Thrust Augmentation. Reissner Anniversary Volume, Edwards, Ann Arbor, Michigan, 1949.Google Scholar
7. Squire, H. B. Jet Flow and its Effect on Aircraft. Aircraft Engineering, Vol. 22, March 1950.Google Scholar
8. Von Glahn, U. H. Use of the Coanda Effect for Jet Deflection and Vertical Lift with Multiple-Flat-Plate and Curved-Plate Deflection Surfaces. N.A.C.A. T.N. 4377, 1958.Google Scholar
9. Newman, B. G. The Deflection of Plane Jets by Adjacent Boundaries—Coanda Effect. Boundary Layer Control Principles and Applications, edited by Lachmann, G. V., Pergamon Press, in print.Google Scholar
10. Von Glahn, U. H. Use of the Coanda Effect for Obtaining Jet Deflection and Lift with a Single Flat-Plate Deflection Surface. N.A.C.A. T.N. 4272, 1958.Google Scholar
11. Lighthill, M. J. Notes on the Deflection of Jets by Insertion of Curved Surfaces and on the Design of Bends in Wind Tunnels. R. & M. 2105, 1945.Google Scholar
12. Yen, K. T. A Theoretical Evaluation of the Coanda Nozzle. Rensselaer Polytechnic Institute, T.R. AE5501, July 1955.Google Scholar
13. Head, M. R. Entrainment in the Turbulent Boundary Layer. A.R.C. 20,383, September 1958.Google Scholar
14. Dodds, J. I. Private communication, 1958.Google Scholar
15. Chapman, D. R., Kuehn, D. M. and Larson, H. K. Investigation of Separated Hows in Supersonic and Subsonic Streams with Emphasis on the Effect of Transition. N.A.C.A. T.N. 3869, 1957.Google Scholar
16. Townsend, A. A. The Structure of Turbulent Shear Flow. Cambridge University Press, 1956.Google Scholar
17. Taylor, G. I. The Use of a Vertical Air Jet as a Windscreen. Mémoires sur la Mecanique des Fluides, offerts à Riabouchinsky, Ministère de l'Air, 1954.Google Scholar
18. Schlichting, H. Boundary-Layer Theory. Pergamon Press, p. 498, 1955.Google Scholar
19. Föthmann, E. Uber turbulente Strahlausbreitung. Ingenieur-Archiv, Vol. 5, pp. 4254, 1934; N.A.C.A. T.M. 789, 1936.CrossRefGoogle Scholar
20. Sigalla, A. Measurements of Skin Friction in a Plane Turbulent Wall Jet. Journal of the Royal Aeronautical Society, Vol. 62, December 1958.CrossRefGoogle Scholar
21. Glauert, M. B. The Wall Jet. Journal of Fluid Mechanics, Vol. 1, 1956.CrossRefGoogle Scholar