Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)
- Volume 21 Issue 3
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- Pages.427-435
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- 1997
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- 1226-4881(pISSN)
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- 2288-5324(eISSN)
DOI QR Code
Correlation of the Wall Skin-Friction and Streamwise Velocity Fluctuations in a Turbulent Boundary Layer(II)
난류경계층에서 벽마찰력과 유동방향 속도성분과의 상관관계(II)
- Yang, Jun-Mo (Dept.of Mechanical Engineering, Graduate School of Seoul National University) ;
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Yu, Jeong-Yeol
;
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Choe, Hae-Cheon
- Published : 1997.03.01
Abstract
Conditional sampling techniques are utilized to investigate the relation between the wall skin-friction and stream wise velocity fluctuations in a turbulent boundary layer. Conditionally averaged results using a peak detection and the VITA (variable-interval time-averaging) technique show that a high skin friction is associated with high frequency components of the wall skin-friction fluctuations. The conditionally averaged wall skin-friction fluctuations obtained by using the VITA technique have a positively-skewed characteristics compared with the conditionally averaged stream wise velocity fluctuations. It is confirmed that there exists a phase shift between the wall skin-friction and stream wise velocity fluctuations, which was also found from the long-time averaged space-time correlations. The amount of phase shift between the wall skin-friction and stream wise velocity fluctuations is the same as that from the long-time averaged space-time correlations and does not change despite the variation of the detection threshold.
Keywords