著者

Sakakibara Jun Machida Nobuteru

出版者

American Institute of Physics

雑誌

Physics of fluids (ISSN:10706631)

巻号頁・発行日

vol.24, no.4, pp.041702, 2012-04

被引用文献数

32 9

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We measured velocity distribution in cross sections of a fully developed turbulentpipe flow upstream and downstream of a 90◦ bend by synchronizing two sets ofa particle image velocimetry (PIV) system. Unsteady undulation of Dean vorticesformed downstream from the bend was characterized by the azimuthal position ofthe stagnation point found on the inner and outer sides of the bend. Linear stochasticestimationwas applied to capture the upstream flowfield conditioned by the azimuthallocation of the stagnation point downstream from the bend. When the inner-sidestagnation point stayed below(above) the symmetry plane, the conditional streamwisevelocity upstream from the bend exhibited high-speed streaks extended in a quasistreamwisedirection on the outer side of the curvature above (below) the symmetryplane.