@article{oai:uec.repo.nii.ac.jp:00009721, author = {Hara, S. and Mamori, H. and Miyazaki, T.}, journal = {International Journal of Heat and Fluid Flow}, month = {Oct}, note = {Opposition controlled fully developed turbulent flow along a thin cylinder is analyzed by means of direct numerical simulations. The influence of cylinder curvature on the skin-friction drag reduction effect by the classical opposition control (i.e., the radial velocity control) is investigated. The curvature of the cylinder affects the uncontrolled flow statistics; for instance, skin-friction coefficient increases while Reynolds shear stress (RSS) and turbulent intensity decrease. However, the control effect in the case of a small curvature is similar to that in channel flow. When the curvature is large, the maximum drag reduction rate decreased. However, the optimal location of the detection plane is the same as that in a flat plate. Further, the drag reduction effect is achieved even on a high detection plane where the drag increases in the flat plate. Although a difference in the drag reduction effect can be observed with a change in the curvature, its mechanism considered in this analysis based on the transport of the Reynolds stress is similar to that of the flat plate.}, title = {Influence of curvature on drag reduction by opposition control in turbulent flow along a thin cylinder}, volume = {85}, year = {2020} }