On the modification of the near-wall coherent structure in a three-dimensional turbulent boundary layer on a free rotating disk
作者:
Hyung Suk Kang,
Haecheon Choi,
Jung Yul Yoo,
期刊:
Physics of Fluids
(AIP Available online 1998)
卷期:
Volume 10,
issue 9
页码: 2315-2322
ISSN:1070-6631
年代: 1998
DOI:10.1063/1.869750
出版商: AIP
数据来源: AIP
摘要:
An experimental study has been performed on a shear-driven three-dimensional turbulent boundary layer in equilibrium over a rotating disk. The objective of the present study is to investigate the modification of the near-wall coherent structure in the three-dimensional turbulent boundary layer developed in this flow. Two-point velocity measurements are carried out with two X-wire probes which are aligned in the local wall-parallel mean velocity direction, which show that strong asymmetries exist in the velocity cross-correlation coefficient in the spanwise direction, and also in the conditionally averaged velocity signals in the vicinity of a strong ejection or sweep, as was shown by Littell and Eaton [J. Fluid Mech.266, 175 (1994)]. However, a quadrant analysis reveals that the Reynolds-shear-stress-producing eddies are nearly symmetric in the spanwise direction and those asymmetries are attributed to the changes in the negative-Reynolds-shear-stress-producing motions which have less relation to the streamwise coherent structures. ©1998 American Institute of Physics.
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