On the Internal Order and Structures in a Transitional Spot
A transitional (laminar to turbulent) spot which develops on a slightly heated laminar boundary layer is investigated. Flow structures of nearly the same scale as the spot have been identified within the spot. The number of structures in the spot increases with streamwise distance, however all structures are convected with the same velocity. This convection velocity depends on the normalized distance from the wall and is almost identical to that of the leading edge of the spot. The increase in the number of structures accounts for the streamwise growth of the spot. There is sufficient evidence to suggest that, the new structures are formed near the trailing edge of the spot.
KeywordsLaminar Boundary Layer Convection Velocity Wire Array Hairpin Vortex Turbulent Spot
Unable to display preview. Download preview PDF.
- ANTONIA, R.A., CHAMBERS, A.J. and SANKARAN, R.: 1985. A Low Speed Wind Tunnel to Study the Structure of a Boundary Layer with Pressure Gradient, Report T.N. - FM 85/1, Department of Mechanical Engineering, University of Newcastle.Google Scholar
- SANKARAN, R., CHAMBERS, A.J. and ANTONIA, R.A.: 1986. The Influence of a Favourable Pressure Gradient on the Growth of a Turbulent Spot, Proc. 9th Australasian Fluid Mechanics Conference, Auckland, 342–345.Google Scholar
- WYGNANSKI, I.: 1983. On Turbulent Spots, in G.K. Patterson and J.L. Zakin (eds.) Symposium on Turbulence: Proc. Seventh Symposium on Turbulence, September, 1981, University of Missouri-Rolla, 390–400.Google Scholar