Near-wall structure in separated flows
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Results obtained from flow-visualisation experiments and skin-friction measurements in the near-wall region of a separation bubble indicate the existence of large coherent structures. The observed patterns can be divided into large low-velocity “pockets” and smaller high-velocity streaks. The existence of these structures can be explained partly by high-velocity material from the free shear layer penetrating to the wall from above. Both the form and the frequency of occurence of these structures differ considerably from those observed in turbulent boundary layers.
KeywordsWall Shear Stress Skin Friction Turbulent Boundary Layer Light Sheet Separation Bubble
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- 8.S. Tardu, C.T. Pham & G. Binder (1991), Effects of longitudinal diffusion in the fluid and of heat conduction to the substrate on the response of wall hot-film gages. In Advances in turbulence 3 (ed. A. V. Johansson & P.H. Alfredsson )Google Scholar
- 9.P.M. Wagner (1991), The use of near-wall hot-wire probes for time-resolved skin-friction measurements. In Advances in turbulence 3 (ed. A. V. Johansson & P.H. Alfredsson )Google Scholar
- 10.A. Dahm & J.D. Vagt (1981), Entwicklung and Herstellung interferenzarmer Hitzdrahtsonden. HFI Institutsbericht IB-0177, TU Berlin.Google Scholar
- 11.P. Dengel, H.H. Fernholz & M. Hess (1987), Skin-friction measurements in two- and three-dimensional highly turbulent flows with separation. In Advances in turbulence 1 (ed. G. Compte-Bellot & J. Mathieu )Google Scholar
- 12.S.W. Pronchik (1983), An experimental investigation of the structure of a turbulent reattaching flow behind a backward-facing step. Ph.D. Thesis, Stanford University.Google Scholar
- 14.M.P. Jaroch & H.H. Fernholz (19899), The three-dimensional character of a nominally two-dimensional separated turbulent shear flow. J. Fluid Mech. 205, 523Google Scholar