Influence of Surface Curvature on Coanda Effect for Vertical Jet Impacting Horizontal Cylinder

Document Type : Regular Article

Authors

1 Shen Wai International School (SWIS), 29 Baishi Third Road, Nanshan, Shenzhen, China

2 Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China

Abstract

The Coanda effect is a tendency of flowing fluid to follow the solid surface rather than to separate under the inertial effect. This paper presents the effects of surface curvature on the Coanda angle and jet deflection for a vertical jet impacting a horizontal cylinder (of diameter D) with Froude numbers Fr = 4.74 and 6.33. The penetration depth h of the cylinder in the jet is varied from h/D = 0.01-0.4 while the jet-to-cylinder diameter ratio d/D is varied from 0.11 to 2.0. For Fr = 4.74, the round jet impacting the cylinder evolves into a planar jet for d/D £ 0.40 where the jet deflection is positive, dictated by the Coanda effect. The deflection of the jet is negative for d/D = 0.60 and 0.83 where the bouncing (inertial) effect overwhelms the Coanda effect. Fr = 4.74, the jet deflects in the positive direction, regardless of d/D. With increasing h/D or decreasing d/D, both deflection and Coanda angles monotonically increase. An intermittent switch of the jet from one side of the cylinder to the other is observed for certain curvature of the cylinder, ascribed to the competition between bouncing and Coanda effects.

Keywords

References

Abdelhamid, T., M. M. Alam and M. Islam (2021). Heat transfer and flow around cylinder: Effect of corner radius and Reynolds number. International Journal of Heat and Mass Transfer 171, 121105.##
Alam, M. M., T. Abdelhamid and A. Sohankar (2020). Effect of cylinder corner radius and attack angle on heat transfer and flow topology. International Journal of Mechanical Sciences 179, 105566.##
Alam, M. M., H. Sakamoto and Y. Zhou (2005). Determination of flow configurations and fluid forces acting on two staggered circular cylinders of equal diameter in cross-flow. Journal of Fluids and Structures 21, 363-394.##
Alam, M. M. and Y. Zhou (2007). Flow around two side-by-side closely spaced circular cylinders. Journal of Fluids and Structures 23, 799-805.##
Alam, M. M., M. Moriya and H. Sakamoto (2003). Aerodynamic characteristics of two side-by-side circular cylinders and application of wavelet analysis on the switching phenomenon. Journal of Fluids and Structures 18, 325-346.##
Alharib, M. and R. Farah (2020). Effect of water-jet flossing on surface roughness and color stability of dental resin-based composites. Journal Clinical and Experimental Dentistry 12(2), 169-177.##
Eisner, T. and D. J. Aneshansley (1982). Spray aiming in bombardier beetles: jet deflection by the coanda effect. Science 215(4528), 83-85.##
Esmond, S. E., L. Quinn and R. K. Weir (2004). Rain and storm water filtration systems (U.S. Patent 6705049).##
Ishigai, S., E. Nishikawa, E. Nishimura and K. Cho (1972). Experimental study of structure of gas flow in tube banks axes normal to flow. Bulletin of the Japan Society of Mechanical Engineers 15, 949-956.##
Jackson, R. R. (1971). Self-Inflating Endotracheal Tube (U. S. Patent 3707151).##
Jambon-Puillet, E., W. Bouwhuis, J. H. Snoeijer and D. Bonn (2019). Liquid helix: how capillarity jets adhere to vertical cylinders. Physical Review Letters 122, 184501.##
Jolkovsky, D. L. and D. M. Lyle (2015). Safety of a water flosser: a literature review. Compendium of Continuing Education in Dentistry 36(2), 146-155.##
Lai, J. C. S. and D. Lu (1996). Effect of wall inclination on the mean flow and turbulence characteristics in a two-dimensional wall jet. International Journal of Heat Fluid Flow 17(4), 377-385.##
Lubert, C. (2010, November). On some recent applications of the coanda effect to acoustics. In Proceedings of Meetings on Acoustics 160ASA. Acoustical Society of America.##
Schuh, H. and B. Person (1964). Heat transfer on circular cylinders exposed to free jet flow. International Journal of Heat and Mass Transfer 7, 1257.##
Skotnicka‑Siepsiak, A. (2022). Pressure distribution on a fat plate in the context of the phenomenon of the Coanda effect hysteresis. Scientific Reports 12, 12687.##

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History

  • Received: 22 September 2022
  • Revised: 29 October 2022
  • Accepted: 24 November 2022
  • Available online: 01 April 2023

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