Transactions of the Korean Society of Mechanical Engineers (대한기계학회논문집)
- Volume 18 Issue 9
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- Pages.2443-2453
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- 1994
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- 1225-5963(pISSN)
DOI QR Code
Turbulence Structures of Flow in Concentric Annuli with Rough Outer Wall
외벽에 거칠기가 있는 이중동심관 유동의 난류구조
Abstract
The structure of turbulence of fully developed flow through four concentric annuli with the rough outer wall was investigated experimentally for a Reynolds number range Re=15, 000-93, 000. Turbulence intensities were measured in three(u, v, w) directions, and turbulence shear stresses in annuli of radius=0.13, 0.26, 0.4 and 0.56, respectively. Due to the square roughness element attached periodically along the axial direction, the radial velocity fluctuations show similar distribution regardless of the different .alpha.cases. However, the axial and circumferential velocity fluctuation profiles demonstrate the longitudinal turbulence structures are strongly influenced by the .alpha. values. The turbulent eddy viscosity deduced form mean velocity distributions and the measured Reynolds shear stresses are also presented and discussed.