角柱のギャロッピングに対する下流平板の影響(流体工学,流体機械)  [in Japanese] Influence of a Downstream Strip-Plate on Galloping of a Square Cylinder in Cruciform Arrangement(Fluids Engineering)  [in Japanese]

Galloping of a square cylinder can be suppressed by the downstream strip-plate set in cruciform arrangement with a gap s. In addition, another strong vibration is generated at certain conditions of the flow velocity and gap s. The specific aim of this work is to confirm generality of these phenomena for various dimension systems and nondimensional parameters by the wind tunnel experiment. When the width of the downstream strip-plate w is equal to the side length of the square cylinder d, the suppression of galloping and the strong vibration are observed for all the square cylinders. The effective region of suppression is affected by w. The strong vibration is confirmed to be the longitudinal vortex excitation from measurement of the dominant frequency of the velocity fluctuation near the cross and flow visualization.