Wake dynamics of a 3D curved cylinder in oblique flows

초록

Three-dimensional numerical simulations were performed to study the effects of flow direction and flow velocity on the flow regime behind a curved pipe represented by a curved circular cylinder. The cylinder is based on a previous study and consists of a quarter segment of a ring and a horizontal part at the end of the ring. The cylinder was rotated in the computational domain to examine five incident flow angles of 0-180 degrees with 45 degrees intervals at Reynolds numbers of 100 and 500. The detailed wake topologies represented by lambda(2) criterion were captured using a Large Eddy Simulation (LES). The curved cylinder leads to different flow regimes along the span, which shows the three-dimensionality of the wake field. At a Reynolds number of 100, the shedding was suppressed after flow angle of 135 degrees, and oblique flow was observed at 90 degrees. At a Reynolds number of 500, vortex dislocation was detected at 90 degrees and 135 degrees. These observations are in good agreement with the three-dimensionality of the wake field that arose due to the curved shape. (C) 2020 Production and hosting by Elsevier B.V. on behalf of Society of Naval Architects of Korea.

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