TY - JOUR
AU - Sung, Hyung Jin
AU - Lee, Jae Hwa
AU - Kim, Kyoungyoun
AU - Sung, Hyung Jin
DA - 2008/06
UR - https://scholarworks.unist.ac.kr/handle/201301/13343
UR - http://www.kci.go.kr/kciportal/ci/sereArticleSearch/ciSereArtiView.kci?sereArticleSearchBean.artiId=ART001253378&locale=en&SID=U278MC5OPZAlH6VbDaQ
AB - Turbulent coherent structures near rod-roughened wall are investigated by analyzing the database of direct numerical simulation of turbulent boundary layer. The surface roughness rods with the height k/δ=0.05 are arranged periodically in Reδ=9000. The roughness sublayer is defined as two-point correlations are not independent of streamwise locations around roughness. The roughness sublayer based on the two-point spatial correlation is different from that given by one-point statistics. Quadrant analysis and probability-weighted Reynolds shear stress indicate that turbulent structures are not affected by surface roughness above the roughness sublayer defined by the spatial correlations. The conditionally-averaged flow fields associated with Reynolds shear stress producing Q2/Q4 events show that though turbulent vortices are affected in the roughness sublayer, these are very similar at different streamwise locations above the roughness sublayer. The Reynolds stress producing turbulent vortices in the log layer (y/δ=0.15) have almost the same geometrical shape as those in the smooth wall-bounded turbulent flows. This suggests that the mechanism by which the Reynolds stress is produced in the log layer has not been significantly affected by the present surface roughness
LA - KOR
PB - 대한기계학회
KW - Direct numerical Simulation (직접수치모사)
KW - Turbulent Boundary Layer (난류경계층)
KW - Surface Roughness (표면조도)
KW - Turbulent Structure (난류구조)
TI - Organized Structure of Turbulent Boundary Layer with Rod-roughened Wall
TT - Organized structure of turbulent boundary layer rod roughened-wall
ER -