Abstract
Coherent structures of a turbulent boundary layer were investigated by hydrogen bubble method. A kind of fast changing structure was observed. That is a spot in which all the hydrogen bubbles vanish much faster than in other regions. This investigation verified that dark-spot is formed by a strong sweep from outer layer. Inside a dark-spot the local instantaneous flow speed might be four times of its neighboring high-speed streaks. Comparing with the low/high speed streaks, both dark-spot and the vortical structures around it are changing very fast. Around dark-spot intensive shear layers are formed and indications of the generation of small-scale structures could be observed.
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References
Cantwell B. Future direction in turbulence research and the role of organized motion. In Lumley JL ed. Whither Turbulence? Turbulence at Crossroads. Proc of a Workshop on Turbulence, Cornell University, March 22–24, 1989. New York: Springer-Verlag. 1990. 97–131
Kline SJ, Reynolds WC, Schraub FA, Runstadler PW. Structures of turbulent boundary layer.J Fluid Mech, 1967, 37: 741–773
Kim HT, Kline SJ, Reynolds WC. The production of turbulence near a smooth wall in a turbulent boundary layer.J Fluid Mech, 1971, 50: 133–160
Smith CR, Walker DA. Sustain mechanism of turbulent boundary layer: The role of vortex development and interactions. In Panton RL ed. Advances in Fluid Mechanics. Vol. 15. Boston, USA: Computational Mechanics Publications, 1997. 13–47
Praturi AK, Brodkey RS. A stereoscopic visual study of the coherent structures in turbulent shear flow.J Fluid Mech, 1978, 89: 251–272
Talmon AM, Kunen JMG, Oom G. Simultaneous flow visualization and Reynolds-stress measurement in a turbulent boundary layer.J Fluid Mech, 1986, 163: 459–478
Lian QX. A visual study of the coherent structure of turbulent boundary layer in flow with adverse pressure gradient.J Fluid Mech, 1990, 215: 101–124
Lian QX, Su TC. The applications of the hydrogen bubble method in the investigations of complex flows.Atlas of Visualization, 1996, 2: 105–115
Lian QX, Su TC. Large vortex in front stagnation region of a square plate induced by a fine interference wire.Science in China (Series A), 1994, 37: 469–477
Xu C, Zhang Z, den Tooder JMJ, Niewstadt FTM. Origin of high kurtosis in the viscous sublayer.Phys Fluids, 1996, 8(7): 1938–1944
Brooke JW, Hanratty TJ. Origin of turbulence producing-eddies in a turbulent channel flow.Phys Fluids A, 1993, 5(4): 1011–1022
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The project supported by the National Natural Science Foundation of China (No. 19672004) and the National Climbing Project
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Qixiang, L. A kind of fast changing coherent structure in a turbulent boundary layer. Acta Mech Sinica 15, 193–200 (1999). https://doi.org/10.1007/BF02486147
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DOI: https://doi.org/10.1007/BF02486147