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Visualization of Microbubbles Affecting Drag Reduction in Turbulent Boundary Layer
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 Title & Authors
Visualization of Microbubbles Affecting Drag Reduction in Turbulent Boundary Layer
Paik, Bu-Geun; Yim, Geun-Tae; Kim, Kwang-Soo; Kim, Kyoung-Youl; Kim, Yoo-Chul;
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 Abstract
Microbubbles moving in the turbulent boundary layer are visualized and investigated in the point of frictional drag reduction. The turbulent boundary layer is formed beneath the surface of the 2-D flat plate located in the tunnel test section. The microbubble generator produces mean bubble diameter of 30 – 50 μm. To capture the micro-bubbles passing through the tiny measurement area of 5.6 mm2 to 200 mm2, the shadowgraphy system is employed appropriately to illuminate bubbles. The velocity field of bubbles reveals that Reynolds stress is reduced in the boundary layer by microbubbles’ activity. To understand the contribution of microbubbles to the drag reduction rate more, much smaller field-of-view is required to visualize the bubble behaviors and to find the 2-D void fraction in the inner boundary layer.
 Keywords
Microbubble;Turbulent boundary layer;Skin friction;PIV(particle image velocimetry);Shadowgraphy;
 Language
Korean
 Cited by
 References
1.
Jacob, B. Olivieri, A. Campana, E.F. & Piva, R., 2010. Drag Reduction by Microbubbles in a Turbulent Boundary Layer. Physics of Fluids, 22, pp.115104-11. crossref(new window)

2.
Kim, D.S. Kim, H.T. & Kim, W.J., 2003. Experimental Study of Friction Drag Reduction in Turbulent Flow with Microbubble Injection. Journal of the Society of Naval Architects of Korea, 40(3), pp.1-8.

3.
Kim, J. Moin, P. & Moser R., 1987. Turbulence Statistics in Fully Developed Channel Flow at Low Reynolds number. Journal of Fluids Mechanics, 177, pp.133-166. crossref(new window)

4.
Kim, J.H. Oh, J.Y. Seo, D.W. & Lee, S.H., 2011. A Study on the Characteristics of an Air Cavity Attached under a Flat Plate. Journal of the Society of Naval Architects of Korea, 48(5), pp.396-403. crossref(new window)

5.
Paik, B.G. Kim, K.Y. & Ahn, J.W., 2009. Measurements of High Velocity Gradient Flow using Bubble Tracers in a Cavitation Tunnel. Journal of Fluids Engineering, 131, pp.091301. crossref(new window)

6.
Paik, B.G. Kim, K.Y. Cho, S.R. Ahn, J.W. Cho, S.R. Kim, K.R. & Chung, Y.U., 2013. Study on the Drag Performance of the Flat Plates Treated by Antifouling Paints. Journal of the Society of Naval Architects of Korea, 50(6), pp.399-406. crossref(new window)